From 1bdb78a89f6618527f2dc23f8f76e83ee77e3ea5 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Fri, 7 Feb 2020 00:09:13 +0200
Subject: vscode: add FIXME about language client shared resource protection

---
 editors/code/src/ctx.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/editors/code/src/ctx.ts b/editors/code/src/ctx.ts
index aa75943bf..a4dcc3037 100644
--- a/editors/code/src/ctx.ts
+++ b/editors/code/src/ctx.ts
@@ -11,6 +11,9 @@ export class Ctx {
     // deal with it.
     //
     // Ideally, this should be replaced with async getter though.
+    // FIXME: this actually needs syncronization of some kind (check how
+    // vscode deals with `deactivate()` call when extension has some work scheduled
+    // on the event loop to get a better picture of what we can do here)
     client: lc.LanguageClient | null = null;
     private extCtx: vscode.ExtensionContext;
     private onDidRestartHooks: Array<(client: lc.LanguageClient) => void> = [];
-- 
cgit v1.2.3


From 3e0e4e90aeeff25db674f8db562c611bd8016482 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Fri, 7 Feb 2020 03:11:24 +0200
Subject: added fetchLatestArtifactMetadata() and downloadFile() functions

---
 editors/code/package-lock.json                     | 25 ++++++++++
 editors/code/package.json                          |  6 ++-
 editors/code/src/github/download_file.ts           | 26 ++++++++++
 .../src/github/fetch_latest_artifact_metadata.ts   | 55 ++++++++++++++++++++++
 4 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 editors/code/src/github/download_file.ts
 create mode 100644 editors/code/src/github/fetch_latest_artifact_metadata.ts

diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index 353af06bf..5c056463e 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -82,6 +82,15 @@
             "integrity": "sha512-nf1LMGZvgFX186geVZR1xMZKKblJiRfiASTHw85zED2kI1yDKHDwTKMdkaCbTlXoRKlGKaDfYywt+V0As30q3w==",
             "dev": true
         },
+        "@types/node-fetch": {
+            "version": "2.5.4",
+            "resolved": "https://registry.npmjs.org/@types/node-fetch/-/node-fetch-2.5.4.tgz",
+            "integrity": "sha512-Oz6id++2qAOFuOlE1j0ouk1dzl3mmI1+qINPNBhi9nt/gVOz0G+13Ao6qjhdF0Ys+eOkhu6JnFmt38bR3H0POQ==",
+            "dev": true,
+            "requires": {
+                "@types/node": "*"
+            }
+        },
         "@types/resolve": {
             "version": "0.0.8",
             "resolved": "https://registry.npmjs.org/@types/resolve/-/resolve-0.0.8.tgz",
@@ -91,6 +100,12 @@
                 "@types/node": "*"
             }
         },
+        "@types/throttle-debounce": {
+            "version": "2.1.0",
+            "resolved": "https://registry.npmjs.org/@types/throttle-debounce/-/throttle-debounce-2.1.0.tgz",
+            "integrity": "sha512-5eQEtSCoESnh2FsiLTxE121IiE60hnMqcb435fShf4bpLRjEu1Eoekht23y6zXS9Ts3l+Szu3TARnTsA0GkOkQ==",
+            "dev": true
+        },
         "@types/vscode": {
             "version": "1.41.0",
             "resolved": "https://registry.npmjs.org/@types/vscode/-/vscode-1.41.0.tgz",
@@ -536,6 +551,11 @@
             "integrity": "sha512-nnbWWOkoWyUsTjKrhgD0dcz22mdkSnpYqbEjIm2nhwhuxlSkpywJmBo8h0ZqJdkp73mb90SssHkN4rsRaBAfAA==",
             "dev": true
         },
+        "node-fetch": {
+            "version": "2.6.0",
+            "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.0.tgz",
+            "integrity": "sha512-8dG4H5ujfvFiqDmVu9fQ5bOHUC15JMjMY/Zumv26oOvvVJjM67KF8koCWIabKQ1GJIa9r2mMZscBq/TbdOcmNA=="
+        },
         "nth-check": {
             "version": "1.0.2",
             "resolved": "https://registry.npmjs.org/nth-check/-/nth-check-1.0.2.tgz",
@@ -719,6 +739,11 @@
                 "has-flag": "^3.0.0"
             }
         },
+        "throttle-debounce": {
+            "version": "2.1.0",
+            "resolved": "https://registry.npmjs.org/throttle-debounce/-/throttle-debounce-2.1.0.tgz",
+            "integrity": "sha512-AOvyNahXQuU7NN+VVvOOX+uW6FPaWdAOdRP5HfwYxAfCzXTFKRMoIMk+n+po318+ktcChx+F1Dd91G3YHeMKyg=="
+        },
         "tmp": {
             "version": "0.0.29",
             "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.29.tgz",
diff --git a/editors/code/package.json b/editors/code/package.json
index 11d37053e..8e23718cd 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -25,18 +25,22 @@
     },
     "dependencies": {
         "jsonc-parser": "^2.1.0",
+        "node-fetch": "^2.6.0",
+        "throttle-debounce": "^2.1.0",
         "vscode-languageclient": "^6.1.0"
     },
     "devDependencies": {
         "@rollup/plugin-commonjs": "^11.0.2",
         "@rollup/plugin-node-resolve": "^7.1.1",
         "@types/node": "^12.12.25",
+        "@types/node-fetch": "^2.5.4",
+        "@types/throttle-debounce": "^2.1.0",
         "@types/vscode": "^1.41.0",
         "rollup": "^1.31.0",
         "tslib": "^1.10.0",
         "tslint": "^5.20.1",
-        "typescript-formatter": "^7.2.2",
         "typescript": "^3.7.5",
+        "typescript-formatter": "^7.2.2",
         "vsce": "^1.71.0"
     },
     "activationEvents": [
diff --git a/editors/code/src/github/download_file.ts b/editors/code/src/github/download_file.ts
new file mode 100644
index 000000000..f40750be9
--- /dev/null
+++ b/editors/code/src/github/download_file.ts
@@ -0,0 +1,26 @@
+import fetch from "node-fetch";
+import { throttle } from "throttle-debounce";
+import * as fs from "fs";
+
+export async function downloadFile(
+    url: string,
+    destFilePath: fs.PathLike,
+    onProgress: (readBytes: number, totalBytes: number) => void
+): Promise<void> {
+    onProgress = throttle(100, /* noTrailing: */ true, onProgress);
+
+    const response = await fetch(url);
+
+    const totalBytes = Number(response.headers.get('content-length'));
+    let readBytes = 0;
+
+    return new Promise<void>((resolve, reject) => response.body
+        .on("data", (chunk: Buffer) => {
+            readBytes += chunk.length;
+            onProgress(readBytes, totalBytes);
+        })
+        .on("end", resolve)
+        .on("error", reject)
+        .pipe(fs.createWriteStream(destFilePath))
+    );
+}
diff --git a/editors/code/src/github/fetch_latest_artifact_metadata.ts b/editors/code/src/github/fetch_latest_artifact_metadata.ts
new file mode 100644
index 000000000..52641ca67
--- /dev/null
+++ b/editors/code/src/github/fetch_latest_artifact_metadata.ts
@@ -0,0 +1,55 @@
+import fetch from "node-fetch";
+
+const GITHUB_API_ENDPOINT_URL = "https://api.github.com";
+
+export interface FetchLatestArtifactMetadataOpts {
+    repoName: string;
+    repoOwner: string;
+    artifactFileName: string;
+}
+
+export interface ArtifactMetadata {
+    releaseName: string;
+    releaseDate: Date;
+    downloadUrl: string;
+}
+
+export async function fetchLatestArtifactMetadata(
+    opts: FetchLatestArtifactMetadataOpts
+): Promise<ArtifactMetadata | null> {
+
+    const repoOwner = encodeURIComponent(opts.repoOwner);
+    const repoName  = encodeURIComponent(opts.repoName);
+
+    const apiEndpointPath = `/repos/${repoOwner}/${repoName}/releases/latest`;
+    const requestUrl = GITHUB_API_ENDPOINT_URL + apiEndpointPath;
+
+    // We skip runtime type checks for simplicity (here we cast from `any` to `Release`)
+
+    const response: GithubRelease = await fetch(requestUrl, {
+            headers: { Accept: "application/vnd.github.v3+json" }
+        })
+        .then(res => res.json());
+
+    const artifact = response.assets.find(artifact => artifact.name === opts.artifactFileName);
+
+    return !artifact ? null : {
+        releaseName: response.name,
+        releaseDate: new Date(response.published_at),
+        downloadUrl: artifact.browser_download_url
+    };
+
+    // Noise denotes tremendous amount of data that we are not using here
+    interface GithubRelease {
+        name: string;
+        published_at: Date;
+        assets: Array<{
+            browser_download_url: string;
+
+            [noise: string]: unknown;
+        }>;
+
+        [noise: string]: unknown;
+    }
+
+}
-- 
cgit v1.2.3


From 5d88c1db38200896d2e4af7836fec95097adf509 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sat, 8 Feb 2020 04:22:44 +0200
Subject: vscode: amended config to use binary from globalStoragePath, added ui
 for downloading

---
 editors/code/package-lock.json                     |  13 +++
 editors/code/package.json                          |   6 +-
 editors/code/src/client.ts                         |  22 +---
 editors/code/src/config.ts                         |  56 ++++++++--
 editors/code/src/ctx.ts                            |   6 +-
 editors/code/src/github/download_file.ts           |  26 -----
 .../src/github/fetch_latest_artifact_metadata.ts   |  55 ----------
 editors/code/src/installation/download_file.ts     |  26 +++++
 .../installation/fetch_latest_artifact_metadata.ts |  47 ++++++++
 editors/code/src/installation/interfaces.ts        |  26 +++++
 editors/code/src/installation/language_server.ts   | 119 +++++++++++++++++++++
 editors/code/tsconfig.json                         |   2 +
 12 files changed, 296 insertions(+), 108 deletions(-)
 delete mode 100644 editors/code/src/github/download_file.ts
 delete mode 100644 editors/code/src/github/fetch_latest_artifact_metadata.ts
 create mode 100644 editors/code/src/installation/download_file.ts
 create mode 100644 editors/code/src/installation/fetch_latest_artifact_metadata.ts
 create mode 100644 editors/code/src/installation/interfaces.ts
 create mode 100644 editors/code/src/installation/language_server.ts

diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index 5c056463e..1b7c8910e 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -753,6 +753,19 @@
                 "os-tmpdir": "~1.0.1"
             }
         },
+        "ts-not-nil": {
+            "version": "1.0.1",
+            "resolved": "https://registry.npmjs.org/ts-not-nil/-/ts-not-nil-1.0.1.tgz",
+            "integrity": "sha512-19+u+3okJddVZlrIdTOdFBaMsHYDInIGDPiujxfRa0RS2Ch5055zVG4GAqa+CZ/Rd1a+7ORSm8O4+2kesPymtw==",
+            "requires": {
+                "ts-typedefs": ">=3.2.0"
+            }
+        },
+        "ts-typedefs": {
+            "version": "3.2.0",
+            "resolved": "https://registry.npmjs.org/ts-typedefs/-/ts-typedefs-3.2.0.tgz",
+            "integrity": "sha512-NglEH2YiY40YxNAvwBISqqXRTKlQq6x+qoCF+tkjPxwrPbrkmq7V3LXavmxrD63fENtMhFkcqgMJtOirtow9iA=="
+        },
         "tslib": {
             "version": "1.10.0",
             "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.10.0.tgz",
diff --git a/editors/code/package.json b/editors/code/package.json
index 8e23718cd..c0a62619d 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -27,6 +27,7 @@
         "jsonc-parser": "^2.1.0",
         "node-fetch": "^2.6.0",
         "throttle-debounce": "^2.1.0",
+        "ts-not-nil": "^1.0.1",
         "vscode-languageclient": "^6.1.0"
     },
     "devDependencies": {
@@ -173,10 +174,11 @@
                 },
                 "rust-analyzer.raLspServerPath": {
                     "type": [
+                        "null",
                         "string"
                     ],
-                    "default": "ra_lsp_server",
-                    "description": "Path to ra_lsp_server executable"
+                    "default": null,
+                    "description": "Path to ra_lsp_server executable (points to bundled binary by default)"
                 },
                 "rust-analyzer.excludeGlobs": {
                     "type": "array",
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 7e7e909dd..7639ed44b 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -1,24 +1,18 @@
-import { homedir } from 'os';
 import * as lc from 'vscode-languageclient';
-import { spawnSync } from 'child_process';
 
 import { window, workspace } from 'vscode';
 import { Config } from './config';
+import { ensureLanguageServerBinary } from './installation/language_server';
 
-export function createClient(config: Config): lc.LanguageClient {
+export async function createClient(config: Config): Promise<null | lc.LanguageClient> {
     // '.' Is the fallback if no folder is open
     // TODO?: Workspace folders support Uri's (eg: file://test.txt).
     // It might be a good idea to test if the uri points to a file.
     const workspaceFolderPath = workspace.workspaceFolders?.[0]?.uri.fsPath ?? '.';
 
-    const raLspServerPath = expandPathResolving(config.raLspServerPath);
-    if (spawnSync(raLspServerPath, ["--version"]).status !== 0) {
-        window.showErrorMessage(
-            `Unable to execute '${raLspServerPath} --version'\n\n` +
-            `Perhaps it is not in $PATH?\n\n` +
-            `PATH=${process.env.PATH}\n`
-        );
-    }
+    const raLspServerPath = await ensureLanguageServerBinary(config.raLspServerSource);
+    if (!raLspServerPath) return null;
+
     const run: lc.Executable = {
         command: raLspServerPath,
         options: { cwd: workspaceFolderPath },
@@ -87,9 +81,3 @@ export function createClient(config: Config): lc.LanguageClient {
     res.registerProposedFeatures();
     return res;
 }
-function expandPathResolving(path: string) {
-    if (path.startsWith('~/')) {
-        return path.replace('~', homedir());
-    }
-    return path;
-}
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 524620433..aca5dab5a 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -1,4 +1,6 @@
+import * as os from "os";
 import * as vscode from 'vscode';
+import { BinarySource, BinarySourceType } from "./installation/interfaces";
 
 const RA_LSP_DEBUG = process.env.__RA_LSP_SERVER_DEBUG;
 
@@ -16,10 +18,24 @@ export interface CargoFeatures {
 }
 
 export class Config {
+    readonly raLspServerGithubArtifactName = {
+        linux: "ra_lsp_server-linux",
+        darwin: "ra_lsp_server-mac",
+        win32: "ra_lsp_server-windows.exe",
+        aix: null,
+        android: null,
+        freebsd: null,
+        openbsd: null,
+        sunos: null,
+        cygwin: null,
+        netbsd: null,
+    }[process.platform];
+
+    raLspServerSource!: null | BinarySource;
+
     highlightingOn = true;
     rainbowHighlightingOn = false;
     enableEnhancedTyping = true;
-    raLspServerPath = RA_LSP_DEBUG || 'ra_lsp_server';
     lruCapacity: null | number = null;
     displayInlayHints = true;
     maxInlayHintLength: null | number = null;
@@ -45,11 +61,20 @@ export class Config {
     private prevCargoWatchOptions: null | CargoWatchOptions = null;
 
     constructor(ctx: vscode.ExtensionContext) {
-        vscode.workspace.onDidChangeConfiguration(_ => this.refresh(), null, ctx.subscriptions);
-        this.refresh();
+        vscode.workspace.onDidChangeConfiguration(_ => this.refresh(ctx), null, ctx.subscriptions);
+        this.refresh(ctx);
+    }
+
+    private static expandPathResolving(path: string) {
+        if (path.startsWith('~/')) {
+            return path.replace('~', os.homedir());
+        }
+        return path;
     }
 
-    private refresh() {
+    // FIXME: revisit the logic for `if (.has(...)) config.get(...)` set default
+    // values only in one place (i.e. remove default values from non-readonly members declarations)
+    private refresh(ctx: vscode.ExtensionContext) {
         const config = vscode.workspace.getConfiguration('rust-analyzer');
 
         let requireReloadMessage = null;
@@ -82,9 +107,26 @@ export class Config {
             this.prevEnhancedTyping = this.enableEnhancedTyping;
         }
 
-        if (config.has('raLspServerPath')) {
-            this.raLspServerPath =
-                RA_LSP_DEBUG || (config.get('raLspServerPath') as string);
+        {
+            const raLspServerPath = RA_LSP_DEBUG ?? config.get<null | string>("raLspServerPath");
+            if (raLspServerPath) {
+                this.raLspServerSource = {
+                    type: BinarySourceType.ExplicitPath,
+                    path: Config.expandPathResolving(raLspServerPath)
+                };
+            } else if (this.raLspServerGithubArtifactName) {
+                this.raLspServerSource = {
+                    type: BinarySourceType.GithubBinary,
+                    dir: ctx.globalStoragePath,
+                    file: this.raLspServerGithubArtifactName,
+                    repo: {
+                        name: "rust-analyzer",
+                        owner: "rust-analyzer",
+                    }
+                };
+            } else {
+                this.raLspServerSource = null;
+            }
         }
 
         if (config.has('cargo-watch.enable')) {
diff --git a/editors/code/src/ctx.ts b/editors/code/src/ctx.ts
index a4dcc3037..f0e2d72f7 100644
--- a/editors/code/src/ctx.ts
+++ b/editors/code/src/ctx.ts
@@ -29,7 +29,11 @@ export class Ctx {
             await old.stop();
         }
         this.client = null;
-        const client = createClient(this.config);
+        const client = await createClient(this.config);
+        if (!client) {
+            throw new Error("Rust Analyzer Language Server is not available");
+        }
+
         this.pushCleanup(client.start());
         await client.onReady();
 
diff --git a/editors/code/src/github/download_file.ts b/editors/code/src/github/download_file.ts
deleted file mode 100644
index f40750be9..000000000
--- a/editors/code/src/github/download_file.ts
+++ /dev/null
@@ -1,26 +0,0 @@
-import fetch from "node-fetch";
-import { throttle } from "throttle-debounce";
-import * as fs from "fs";
-
-export async function downloadFile(
-    url: string,
-    destFilePath: fs.PathLike,
-    onProgress: (readBytes: number, totalBytes: number) => void
-): Promise<void> {
-    onProgress = throttle(100, /* noTrailing: */ true, onProgress);
-
-    const response = await fetch(url);
-
-    const totalBytes = Number(response.headers.get('content-length'));
-    let readBytes = 0;
-
-    return new Promise<void>((resolve, reject) => response.body
-        .on("data", (chunk: Buffer) => {
-            readBytes += chunk.length;
-            onProgress(readBytes, totalBytes);
-        })
-        .on("end", resolve)
-        .on("error", reject)
-        .pipe(fs.createWriteStream(destFilePath))
-    );
-}
diff --git a/editors/code/src/github/fetch_latest_artifact_metadata.ts b/editors/code/src/github/fetch_latest_artifact_metadata.ts
deleted file mode 100644
index 52641ca67..000000000
--- a/editors/code/src/github/fetch_latest_artifact_metadata.ts
+++ /dev/null
@@ -1,55 +0,0 @@
-import fetch from "node-fetch";
-
-const GITHUB_API_ENDPOINT_URL = "https://api.github.com";
-
-export interface FetchLatestArtifactMetadataOpts {
-    repoName: string;
-    repoOwner: string;
-    artifactFileName: string;
-}
-
-export interface ArtifactMetadata {
-    releaseName: string;
-    releaseDate: Date;
-    downloadUrl: string;
-}
-
-export async function fetchLatestArtifactMetadata(
-    opts: FetchLatestArtifactMetadataOpts
-): Promise<ArtifactMetadata | null> {
-
-    const repoOwner = encodeURIComponent(opts.repoOwner);
-    const repoName  = encodeURIComponent(opts.repoName);
-
-    const apiEndpointPath = `/repos/${repoOwner}/${repoName}/releases/latest`;
-    const requestUrl = GITHUB_API_ENDPOINT_URL + apiEndpointPath;
-
-    // We skip runtime type checks for simplicity (here we cast from `any` to `Release`)
-
-    const response: GithubRelease = await fetch(requestUrl, {
-            headers: { Accept: "application/vnd.github.v3+json" }
-        })
-        .then(res => res.json());
-
-    const artifact = response.assets.find(artifact => artifact.name === opts.artifactFileName);
-
-    return !artifact ? null : {
-        releaseName: response.name,
-        releaseDate: new Date(response.published_at),
-        downloadUrl: artifact.browser_download_url
-    };
-
-    // Noise denotes tremendous amount of data that we are not using here
-    interface GithubRelease {
-        name: string;
-        published_at: Date;
-        assets: Array<{
-            browser_download_url: string;
-
-            [noise: string]: unknown;
-        }>;
-
-        [noise: string]: unknown;
-    }
-
-}
diff --git a/editors/code/src/installation/download_file.ts b/editors/code/src/installation/download_file.ts
new file mode 100644
index 000000000..7b537e114
--- /dev/null
+++ b/editors/code/src/installation/download_file.ts
@@ -0,0 +1,26 @@
+import fetch from "node-fetch";
+import { throttle } from "throttle-debounce";
+import * as fs from "fs";
+
+export async function downloadFile(
+    url: string,
+    destFilePath: fs.PathLike,
+    onProgress: (readBytes: number, totalBytes: number) => void
+): Promise<void> {
+    onProgress = throttle(1000, /* noTrailing: */ true, onProgress);
+
+    const response = await fetch(url);
+
+    const totalBytes = Number(response.headers.get('content-length'));
+    let readBytes = 0;
+
+    return new Promise<void>((resolve, reject) => response.body
+        .on("data", (chunk: Buffer) => {
+            readBytes += chunk.length;
+            onProgress(readBytes, totalBytes);
+        })
+        .on("end", resolve)
+        .on("error", reject)
+        .pipe(fs.createWriteStream(destFilePath))
+    );
+}
diff --git a/editors/code/src/installation/fetch_latest_artifact_metadata.ts b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
new file mode 100644
index 000000000..f07431aac
--- /dev/null
+++ b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
@@ -0,0 +1,47 @@
+import fetch from "node-fetch";
+import { GithubRepo, ArtifactMetadata } from "./interfaces";
+
+const GITHUB_API_ENDPOINT_URL = "https://api.github.com";
+
+export interface FetchLatestArtifactMetadataOpts {
+    repo: GithubRepo;
+    artifactFileName: string;
+}
+
+export async function fetchLatestArtifactMetadata(
+    opts: FetchLatestArtifactMetadataOpts
+): Promise<null | ArtifactMetadata> {
+
+    const repoOwner = encodeURIComponent(opts.repo.owner);
+    const repoName  = encodeURIComponent(opts.repo.name);
+
+    const apiEndpointPath = `/repos/${repoOwner}/${repoName}/releases/latest`;
+    const requestUrl = GITHUB_API_ENDPOINT_URL + apiEndpointPath;
+
+    // We skip runtime type checks for simplicity (here we cast from `any` to `Release`)
+
+    const response: GithubRelease = await fetch(requestUrl, {
+            headers: { Accept: "application/vnd.github.v3+json" }
+        })
+        .then(res => res.json());
+
+    const artifact = response.assets.find(artifact => artifact.name === opts.artifactFileName);
+
+    return !artifact ? null : {
+        releaseName: response.name,
+        downloadUrl: artifact.browser_download_url
+    };
+
+    // Noise denotes tremendous amount of data that we are not using here
+    interface GithubRelease {
+        name: string;
+        assets: Array<{
+            browser_download_url: string;
+
+            [noise: string]: unknown;
+        }>;
+
+        [noise: string]: unknown;
+    }
+
+}
diff --git a/editors/code/src/installation/interfaces.ts b/editors/code/src/installation/interfaces.ts
new file mode 100644
index 000000000..f54e24e26
--- /dev/null
+++ b/editors/code/src/installation/interfaces.ts
@@ -0,0 +1,26 @@
+export interface GithubRepo {
+    name: string;
+    owner: string;
+}
+
+export interface ArtifactMetadata {
+    releaseName: string;
+    downloadUrl: string;
+}
+
+
+export enum BinarySourceType { ExplicitPath, GithubBinary }
+
+export type BinarySource = EplicitPathSource | GithubBinarySource;
+
+export interface EplicitPathSource {
+    type: BinarySourceType.ExplicitPath;
+    path: string;
+}
+
+export interface GithubBinarySource {
+    type: BinarySourceType.GithubBinary;
+    repo: GithubRepo;
+    dir: string;
+    file: string;
+}
diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
new file mode 100644
index 000000000..2b3ce6621
--- /dev/null
+++ b/editors/code/src/installation/language_server.ts
@@ -0,0 +1,119 @@
+import { unwrapNotNil } from "ts-not-nil";
+import { spawnSync } from "child_process";
+import * as vscode from "vscode";
+import * as path from "path";
+import { strict as assert } from "assert";
+import { promises as fs } from "fs";
+
+import { BinarySource, BinarySourceType, GithubBinarySource } from "./interfaces";
+import { fetchLatestArtifactMetadata } from "./fetch_latest_artifact_metadata";
+import { downloadFile } from "./download_file";
+
+export async function downloadLatestLanguageServer(
+    {file: artifactFileName, dir: installationDir, repo}: GithubBinarySource
+) {
+    const binaryMetadata = await fetchLatestArtifactMetadata({ artifactFileName, repo });
+
+    const {
+        releaseName,
+        downloadUrl
+    } = unwrapNotNil(binaryMetadata, `Latest GitHub release lacks "${artifactFileName}" file`);
+
+    await fs.mkdir(installationDir).catch(err => assert.strictEqual(
+        err && err.code,
+        "EEXIST",
+        `Couldn't create directory "${installationDir}" to download `+
+        `language server binary: ${err.message}`
+    ));
+
+    const installationPath = path.join(installationDir, artifactFileName);
+
+    await vscode.window.withProgress(
+        {
+            location: vscode.ProgressLocation.Notification,
+            cancellable: false, // FIXME: add support for canceling download?
+            title: `Downloading language server ${releaseName}`
+        },
+        async (progress, _) => {
+            let lastPrecentage = 0;
+            await downloadFile(downloadUrl, installationPath, (readBytes, totalBytes) => {
+                const newPercentage = (readBytes / totalBytes) * 100;
+                progress.report({
+                    message: newPercentage.toFixed(0) + "%",
+                    increment: newPercentage - lastPrecentage
+                });
+
+                lastPrecentage = newPercentage;
+            });
+        }
+    );
+
+    await fs.chmod(installationPath, 111); // Set xxx permissions
+}
+export async function ensureLanguageServerBinary(
+    langServerSource: null | BinarySource
+): Promise<null | string> {
+
+    if (!langServerSource) {
+        vscode.window.showErrorMessage(
+            "Unfortunately we don't ship binaries for your platform yet. " +
+            "You need to manually clone rust-analyzer repository and " +
+            "run `cargo xtask install --server` to build the language server from sources. " +
+            "If you feel that your platform should be supported, please create an issue " +
+            "about that [here](https://github.com/rust-analyzer/rust-analyzer/issues) and we " +
+            "will consider it."
+        );
+        return null;
+    }
+
+    switch (langServerSource.type) {
+        case BinarySourceType.ExplicitPath: {
+            if (isBinaryAvailable(langServerSource.path)) {
+                return langServerSource.path;
+            }
+            vscode.window.showErrorMessage(
+                `Unable to execute ${'`'}${langServerSource.path} --version${'`'}. ` +
+                "To use the bundled language server, set `rust-analyzer.raLspServerPath` " +
+                "value to `null` or remove it from the settings to use it by default."
+            );
+            return null;
+        }
+        case BinarySourceType.GithubBinary: {
+            const bundledBinaryPath = path.join(langServerSource.dir, langServerSource.file);
+
+            if (!isBinaryAvailable(bundledBinaryPath)) {
+                const userResponse = await vscode.window.showInformationMessage(
+                    `Language server binary for rust-analyzer was not found. ` +
+                    `Do you want to download it now?`,
+                    "Download now", "Cancel"
+                );
+                if (userResponse !== "Download now") return null;
+
+                try {
+                    await downloadLatestLanguageServer(langServerSource);
+                } catch (err) {
+                    await vscode.window.showErrorMessage(
+                        `Failed to download language server from ${langServerSource.repo.name} ` +
+                        `GitHub repository: ${err.message}`
+                    );
+                    return null;
+                }
+
+
+                assert(
+                    isBinaryAvailable(bundledBinaryPath),
+                    "Downloaded language server binary is not functional"
+                );
+
+                vscode.window.showInformationMessage(
+                    "Rust analyzer language server was successfully installed"
+                );
+            }
+            return bundledBinaryPath;
+        }
+    }
+
+    function isBinaryAvailable(binaryPath: string) {
+        return spawnSync(binaryPath, ["--version"]).status === 0;
+    }
+}
diff --git a/editors/code/tsconfig.json b/editors/code/tsconfig.json
index e60eb8e5e..0c7702974 100644
--- a/editors/code/tsconfig.json
+++ b/editors/code/tsconfig.json
@@ -6,6 +6,8 @@
         "lib": [
             "es2019"
         ],
+        "esModuleInterop": true,
+        "allowSyntheticDefaultImports": true,
         "sourceMap": true,
         "rootDir": "src",
         "strict": true,
-- 
cgit v1.2.3


From f7ef72db64e75dadf6f7cae9d739a0a6e8d8f4b4 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sat, 8 Feb 2020 20:07:00 +0200
Subject: vscode: changed chmod value to 755 as per @lnicola

---
 editors/code/src/installation/language_server.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index 2b3ce6621..8d8c62952 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -12,7 +12,7 @@ import { downloadFile } from "./download_file";
 export async function downloadLatestLanguageServer(
     {file: artifactFileName, dir: installationDir, repo}: GithubBinarySource
 ) {
-    const binaryMetadata = await fetchLatestArtifactMetadata({ artifactFileName, repo });
+    const binaryMetadata = await fetchLatestArtifactMetadata(repo, artifactFileName);
 
     const {
         releaseName,
@@ -20,7 +20,7 @@ export async function downloadLatestLanguageServer(
     } = unwrapNotNil(binaryMetadata, `Latest GitHub release lacks "${artifactFileName}" file`);
 
     await fs.mkdir(installationDir).catch(err => assert.strictEqual(
-        err && err.code,
+        err?.code,
         "EEXIST",
         `Couldn't create directory "${installationDir}" to download `+
         `language server binary: ${err.message}`
@@ -48,7 +48,7 @@ export async function downloadLatestLanguageServer(
         }
     );
 
-    await fs.chmod(installationPath, 111); // Set xxx permissions
+    await fs.chmod(installationPath, 755); // Set (rwx, r_x, r_x) permissions
 }
 export async function ensureLanguageServerBinary(
     langServerSource: null | BinarySource
-- 
cgit v1.2.3


From 6ef912f9259a78495fdba6a37bef7d78c4e0a4fd Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sat, 8 Feb 2020 20:18:33 +0200
Subject: vscode: converted fetchLatestArtifactMetadata params to positional,
 added docs

---
 .../installation/fetch_latest_artifact_metadata.ts   | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/editors/code/src/installation/fetch_latest_artifact_metadata.ts b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
index f07431aac..cda955af2 100644
--- a/editors/code/src/installation/fetch_latest_artifact_metadata.ts
+++ b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
@@ -3,29 +3,28 @@ import { GithubRepo, ArtifactMetadata } from "./interfaces";
 
 const GITHUB_API_ENDPOINT_URL = "https://api.github.com";
 
-export interface FetchLatestArtifactMetadataOpts {
-    repo: GithubRepo;
-    artifactFileName: string;
-}
-
+/**
+ * Fetches the latest release from GitHub `repo` and returns metadata about
+ * `artifactFileName` shipped with this release or `null` if no such artifact was published.
+ */
 export async function fetchLatestArtifactMetadata(
-    opts: FetchLatestArtifactMetadataOpts
+    repo: GithubRepo, artifactFileName: string
 ): Promise<null | ArtifactMetadata> {
 
-    const repoOwner = encodeURIComponent(opts.repo.owner);
-    const repoName  = encodeURIComponent(opts.repo.name);
+    const repoOwner = encodeURIComponent(repo.owner);
+    const repoName  = encodeURIComponent(repo.name);
 
     const apiEndpointPath = `/repos/${repoOwner}/${repoName}/releases/latest`;
     const requestUrl = GITHUB_API_ENDPOINT_URL + apiEndpointPath;
 
-    // We skip runtime type checks for simplicity (here we cast from `any` to `Release`)
+    // We skip runtime type checks for simplicity (here we cast from `any` to `GithubRelease`)
 
     const response: GithubRelease = await fetch(requestUrl, {
             headers: { Accept: "application/vnd.github.v3+json" }
         })
         .then(res => res.json());
 
-    const artifact = response.assets.find(artifact => artifact.name === opts.artifactFileName);
+    const artifact = response.assets.find(artifact => artifact.name === artifactFileName);
 
     return !artifact ? null : {
         releaseName: response.name,
@@ -36,6 +35,7 @@ export async function fetchLatestArtifactMetadata(
     interface GithubRelease {
         name: string;
         assets: Array<{
+            name: string;
             browser_download_url: string;
 
             [noise: string]: unknown;
-- 
cgit v1.2.3


From 4e85254444cfaf34fefc253ecd0b43b786e31dd8 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sat, 8 Feb 2020 21:03:27 +0200
Subject: vscode: add docs to installation module interfaces and sanity check
 to donloadFile()

---
 editors/code/src/installation/download_file.ts | 10 +++++++-
 editors/code/src/installation/interfaces.ts    | 33 +++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/editors/code/src/installation/download_file.ts b/editors/code/src/installation/download_file.ts
index 7b537e114..0cc5fc0cb 100644
--- a/editors/code/src/installation/download_file.ts
+++ b/editors/code/src/installation/download_file.ts
@@ -1,17 +1,25 @@
 import fetch from "node-fetch";
 import { throttle } from "throttle-debounce";
 import * as fs from "fs";
+import { strict as assert } from "assert";
 
+/**
+ * Downloads file from `url` and stores it at `destFilePath`.
+ * `onProgress` callback is periodically called to track the progress of downloading,
+ * it gets the already read and total amount of bytes to read as its parameters.
+ */
 export async function downloadFile(
     url: string,
     destFilePath: fs.PathLike,
     onProgress: (readBytes: number, totalBytes: number) => void
 ): Promise<void> {
-    onProgress = throttle(1000, /* noTrailing: */ true, onProgress);
+    onProgress = throttle(500, /* noTrailing: */ true, onProgress);
 
     const response = await fetch(url);
 
     const totalBytes = Number(response.headers.get('content-length'));
+    assert(!Number.isNaN(totalBytes), "Sanity check of content-length protocol");
+
     let readBytes = 0;
 
     return new Promise<void>((resolve, reject) => response.body
diff --git a/editors/code/src/installation/interfaces.ts b/editors/code/src/installation/interfaces.ts
index f54e24e26..03eac5b79 100644
--- a/editors/code/src/installation/interfaces.ts
+++ b/editors/code/src/installation/interfaces.ts
@@ -3,24 +3,51 @@ export interface GithubRepo {
     owner: string;
 }
 
+/**
+ * Metadata about particular artifact retrieved from GitHub releases.
+ */
 export interface ArtifactMetadata {
     releaseName: string;
     downloadUrl: string;
 }
 
-
+/**
+ * Type tag for `BinarySource` discriminated union.
+ */
 export enum BinarySourceType { ExplicitPath, GithubBinary }
 
-export type BinarySource = EplicitPathSource | GithubBinarySource;
+/**
+ * Represents the source of a binary artifact which is either specified by the user
+ * explicitly, or bundled by this extension from GitHub releases.
+ */
+export type BinarySource = ExplicitPathSource | GithubBinarySource;
+
 
-export interface EplicitPathSource {
+export interface ExplicitPathSource {
     type: BinarySourceType.ExplicitPath;
+
+    /**
+     * Filesystem path to the binary specified by the user explicitly.
+     */
     path: string;
 }
 
 export interface GithubBinarySource {
     type: BinarySourceType.GithubBinary;
+
+    /**
+     * Repository where the binary is stored.
+     */
     repo: GithubRepo;
+
+    /**
+     * Directory on the filesystem where the bundled binary is stored.
+     */
     dir: string;
+
+    /**
+     * Name of the binary file. It is stored under the same name on GitHub releases
+     * and in local `.dir`.
+     */
     file: string;
 }
-- 
cgit v1.2.3


From 9791b6a8de7149d97cdf9880d86bfc9e640c8297 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sat, 8 Feb 2020 21:24:29 +0200
Subject: vscode: add name to the second unused argument of withProgress()
 callback

---
 editors/code/src/installation/language_server.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index 8d8c62952..b75d3a00a 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -34,7 +34,7 @@ export async function downloadLatestLanguageServer(
             cancellable: false, // FIXME: add support for canceling download?
             title: `Downloading language server ${releaseName}`
         },
-        async (progress, _) => {
+        async (progress, _cancellationToken) => {
             let lastPrecentage = 0;
             await downloadFile(downloadUrl, installationPath, (readBytes, totalBytes) => {
                 const newPercentage = (readBytes / totalBytes) * 100;
-- 
cgit v1.2.3


From bdd88c2fad272f96a8212e5230010f7c02b4d15d Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sat, 8 Feb 2020 21:25:03 +0200
Subject: vscode: reduce throttle latency of downloadFile() progress callback
 for smoother UX

---
 editors/code/src/installation/download_file.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/editors/code/src/installation/download_file.ts b/editors/code/src/installation/download_file.ts
index 0cc5fc0cb..ec16dcd66 100644
--- a/editors/code/src/installation/download_file.ts
+++ b/editors/code/src/installation/download_file.ts
@@ -13,7 +13,7 @@ export async function downloadFile(
     destFilePath: fs.PathLike,
     onProgress: (readBytes: number, totalBytes: number) => void
 ): Promise<void> {
-    onProgress = throttle(500, /* noTrailing: */ true, onProgress);
+    onProgress = throttle(200, /* noTrailing: */ true, onProgress);
 
     const response = await fetch(url);
 
-- 
cgit v1.2.3


From 539daf4454e3f11424a469e8fba26cacb325176a Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 00:27:04 +0200
Subject: vscode: refactor platform artifact name query to switch statement,
 move BinarySource union variants into a namespace

---
 editors/code/src/client.ts                       |  2 +-
 editors/code/src/config.ts                       | 89 ++++++++++++++----------
 editors/code/src/installation/interfaces.ts      | 58 +++++++--------
 editors/code/src/installation/language_server.ts | 10 +--
 4 files changed, 89 insertions(+), 70 deletions(-)

diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 7639ed44b..2e3d4aba2 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -10,7 +10,7 @@ export async function createClient(config: Config): Promise<null | lc.LanguageCl
     // It might be a good idea to test if the uri points to a file.
     const workspaceFolderPath = workspace.workspaceFolders?.[0]?.uri.fsPath ?? '.';
 
-    const raLspServerPath = await ensureLanguageServerBinary(config.raLspServerSource);
+    const raLspServerPath = await ensureLanguageServerBinary(config.langServerSource);
     if (!raLspServerPath) return null;
 
     const run: lc.Executable = {
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index aca5dab5a..f216ab461 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -1,6 +1,6 @@
 import * as os from "os";
 import * as vscode from 'vscode';
-import { BinarySource, BinarySourceType } from "./installation/interfaces";
+import { BinarySource } from "./installation/interfaces";
 
 const RA_LSP_DEBUG = process.env.__RA_LSP_SERVER_DEBUG;
 
@@ -18,20 +18,7 @@ export interface CargoFeatures {
 }
 
 export class Config {
-    readonly raLspServerGithubArtifactName = {
-        linux: "ra_lsp_server-linux",
-        darwin: "ra_lsp_server-mac",
-        win32: "ra_lsp_server-windows.exe",
-        aix: null,
-        android: null,
-        freebsd: null,
-        openbsd: null,
-        sunos: null,
-        cygwin: null,
-        netbsd: null,
-    }[process.platform];
-
-    raLspServerSource!: null | BinarySource;
+    langServerSource!: null | BinarySource;
 
     highlightingOn = true;
     rainbowHighlightingOn = false;
@@ -72,6 +59,56 @@ export class Config {
         return path;
     }
 
+    /**
+     * Name of the binary artifact for `ra_lsp_server` that is published for
+     * `platform` on GitHub releases. (It is also stored under the same name when
+     * downloaded by the extension).
+     */
+    private static prebuiltLangServerFileName(platform: NodeJS.Platform): null | string {
+        switch (platform) {
+            case "linux":  return "ra_lsp_server-linux";
+            case "darwin": return "ra_lsp_server-mac";
+            case "win32":  return "ra_lsp_server-windows.exe";
+
+            // Users on these platforms yet need to manually build from sources
+            case "aix":
+            case "android":
+            case "freebsd":
+            case "openbsd":
+            case "sunos":
+            case "cygwin":
+            case "netbsd": return null;
+            // The list of platforms is exhaustive see (`NodeJS.Platform` type definition)
+        }
+    }
+
+    private static langServerBinarySource(
+        ctx: vscode.ExtensionContext,
+        config: vscode.WorkspaceConfiguration
+    ): null | BinarySource {
+        const raLspServerPath = RA_LSP_DEBUG ?? config.get<null | string>("raLspServerPath");
+
+        if (raLspServerPath) {
+            return {
+                type: BinarySource.Type.ExplicitPath,
+                path: Config.expandPathResolving(raLspServerPath)
+            };
+        }
+
+        const prebuiltBinaryName = Config.prebuiltLangServerFileName(process.platform);
+
+        return !prebuiltBinaryName ? null : {
+            type: BinarySource.Type.GithubRelease,
+            dir: ctx.globalStoragePath,
+            file: prebuiltBinaryName,
+            repo: {
+                name: "rust-analyzer",
+                owner: "rust-analyzer",
+            }
+        };
+    }
+
+
     // FIXME: revisit the logic for `if (.has(...)) config.get(...)` set default
     // values only in one place (i.e. remove default values from non-readonly members declarations)
     private refresh(ctx: vscode.ExtensionContext) {
@@ -107,27 +144,7 @@ export class Config {
             this.prevEnhancedTyping = this.enableEnhancedTyping;
         }
 
-        {
-            const raLspServerPath = RA_LSP_DEBUG ?? config.get<null | string>("raLspServerPath");
-            if (raLspServerPath) {
-                this.raLspServerSource = {
-                    type: BinarySourceType.ExplicitPath,
-                    path: Config.expandPathResolving(raLspServerPath)
-                };
-            } else if (this.raLspServerGithubArtifactName) {
-                this.raLspServerSource = {
-                    type: BinarySourceType.GithubBinary,
-                    dir: ctx.globalStoragePath,
-                    file: this.raLspServerGithubArtifactName,
-                    repo: {
-                        name: "rust-analyzer",
-                        owner: "rust-analyzer",
-                    }
-                };
-            } else {
-                this.raLspServerSource = null;
-            }
-        }
+        this.langServerSource = Config.langServerBinarySource(ctx, config);
 
         if (config.has('cargo-watch.enable')) {
             this.cargoWatchOptions.enable = config.get<boolean>(
diff --git a/editors/code/src/installation/interfaces.ts b/editors/code/src/installation/interfaces.ts
index 03eac5b79..8039d0b90 100644
--- a/editors/code/src/installation/interfaces.ts
+++ b/editors/code/src/installation/interfaces.ts
@@ -11,43 +11,45 @@ export interface ArtifactMetadata {
     downloadUrl: string;
 }
 
-/**
- * Type tag for `BinarySource` discriminated union.
- */
-export enum BinarySourceType { ExplicitPath, GithubBinary }
-
 /**
  * Represents the source of a binary artifact which is either specified by the user
  * explicitly, or bundled by this extension from GitHub releases.
  */
-export type BinarySource = ExplicitPathSource | GithubBinarySource;
-
-
-export interface ExplicitPathSource {
-    type: BinarySourceType.ExplicitPath;
+export type BinarySource = BinarySource.ExplicitPath | BinarySource.GithubRelease;
 
+export namespace BinarySource {
     /**
-     * Filesystem path to the binary specified by the user explicitly.
+     * Type tag for `BinarySource` discriminated union.
      */
-    path: string;
-}
+    export const enum Type { ExplicitPath, GithubRelease }
 
-export interface GithubBinarySource {
-    type: BinarySourceType.GithubBinary;
+    export interface ExplicitPath {
+        type: Type.ExplicitPath;
 
-    /**
-     * Repository where the binary is stored.
-     */
-    repo: GithubRepo;
+        /**
+         * Filesystem path to the binary specified by the user explicitly.
+         */
+        path: string;
+    }
 
-    /**
-     * Directory on the filesystem where the bundled binary is stored.
-     */
-    dir: string;
+    export interface GithubRelease {
+        type: Type.GithubRelease;
+
+        /**
+         * Repository where the binary is stored.
+         */
+        repo: GithubRepo;
+
+        /**
+         * Directory on the filesystem where the bundled binary is stored.
+         */
+        dir: string;
+
+        /**
+         * Name of the binary file. It is stored under the same name on GitHub releases
+         * and in local `.dir`.
+         */
+        file: string;
+    }
 
-    /**
-     * Name of the binary file. It is stored under the same name on GitHub releases
-     * and in local `.dir`.
-     */
-    file: string;
 }
diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index b75d3a00a..522d59eb5 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -5,12 +5,12 @@ import * as path from "path";
 import { strict as assert } from "assert";
 import { promises as fs } from "fs";
 
-import { BinarySource, BinarySourceType, GithubBinarySource } from "./interfaces";
+import { BinarySource } from "./interfaces";
 import { fetchLatestArtifactMetadata } from "./fetch_latest_artifact_metadata";
 import { downloadFile } from "./download_file";
 
 export async function downloadLatestLanguageServer(
-    {file: artifactFileName, dir: installationDir, repo}: GithubBinarySource
+    {file: artifactFileName, dir: installationDir, repo}: BinarySource.GithubRelease
 ) {
     const binaryMetadata = await fetchLatestArtifactMetadata(repo, artifactFileName);
 
@@ -67,7 +67,7 @@ export async function ensureLanguageServerBinary(
     }
 
     switch (langServerSource.type) {
-        case BinarySourceType.ExplicitPath: {
+        case BinarySource.Type.ExplicitPath: {
             if (isBinaryAvailable(langServerSource.path)) {
                 return langServerSource.path;
             }
@@ -78,7 +78,7 @@ export async function ensureLanguageServerBinary(
             );
             return null;
         }
-        case BinarySourceType.GithubBinary: {
+        case BinarySource.Type.GithubRelease: {
             const bundledBinaryPath = path.join(langServerSource.dir, langServerSource.file);
 
             if (!isBinaryAvailable(bundledBinaryPath)) {
@@ -106,7 +106,7 @@ export async function ensureLanguageServerBinary(
                 );
 
                 vscode.window.showInformationMessage(
-                    "Rust analyzer language server was successfully installed"
+                    "Rust analyzer language server was successfully installed 🦀"
                 );
             }
             return bundledBinaryPath;
-- 
cgit v1.2.3


From 8f291c0089700ab17fafddde33dc12515ba45662 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 00:28:32 +0200
Subject: vscode: refactor comment

---
 editors/code/src/config.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index f216ab461..5aed8c9f3 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -78,7 +78,7 @@ export class Config {
             case "sunos":
             case "cygwin":
             case "netbsd": return null;
-            // The list of platforms is exhaustive see (`NodeJS.Platform` type definition)
+            // The list of platforms is exhaustive (see `NodeJS.Platform` type definition)
         }
     }
 
-- 
cgit v1.2.3


From fd6a98ef6e8cb3ee4d578bf90ad327df548dd1c5 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 00:42:51 +0200
Subject: vscode: rename raLspServer variable to langServer

---
 editors/code/src/config.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 5aed8c9f3..46394600b 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -86,12 +86,12 @@ export class Config {
         ctx: vscode.ExtensionContext,
         config: vscode.WorkspaceConfiguration
     ): null | BinarySource {
-        const raLspServerPath = RA_LSP_DEBUG ?? config.get<null | string>("raLspServerPath");
+        const langServerPath = RA_LSP_DEBUG ?? config.get<null | string>("raLspServerPath");
 
-        if (raLspServerPath) {
+        if (langServerPath) {
             return {
                 type: BinarySource.Type.ExplicitPath,
-                path: Config.expandPathResolving(raLspServerPath)
+                path: Config.expandPathResolving(langServerPath)
             };
         }
 
-- 
cgit v1.2.3


From d08ae7e82f9eb4abb92f1274ea361acb21fd7b87 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 00:58:53 +0200
Subject: vscode: minor names and message contents changes

---
 editors/code/src/ctx.ts                          |  5 ++++-
 editors/code/src/installation/language_server.ts | 16 ++++++++--------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/editors/code/src/ctx.ts b/editors/code/src/ctx.ts
index f0e2d72f7..70042a479 100644
--- a/editors/code/src/ctx.ts
+++ b/editors/code/src/ctx.ts
@@ -31,7 +31,10 @@ export class Ctx {
         this.client = null;
         const client = await createClient(this.config);
         if (!client) {
-            throw new Error("Rust Analyzer Language Server is not available");
+            throw new Error(
+                "Rust Analyzer Language Server is not available. " +
+                "Please, ensure its [proper installation](https://github.com/rust-analyzer/rust-analyzer/tree/master/docs/user#vs-code)."
+            );
         }
 
         this.pushCleanup(client.start());
diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index 522d59eb5..d09fc63a7 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -72,19 +72,19 @@ export async function ensureLanguageServerBinary(
                 return langServerSource.path;
             }
             vscode.window.showErrorMessage(
-                `Unable to execute ${'`'}${langServerSource.path} --version${'`'}. ` +
-                "To use the bundled language server, set `rust-analyzer.raLspServerPath` " +
+                `Unable to run ${langServerSource.path} binary. ` +
+                "To use the pre-built language server, set `rust-analyzer.raLspServerPath` " +
                 "value to `null` or remove it from the settings to use it by default."
             );
             return null;
         }
         case BinarySource.Type.GithubRelease: {
-            const bundledBinaryPath = path.join(langServerSource.dir, langServerSource.file);
+            const prebuiltBinaryPath = path.join(langServerSource.dir, langServerSource.file);
 
-            if (!isBinaryAvailable(bundledBinaryPath)) {
+            if (!isBinaryAvailable(prebuiltBinaryPath)) {
                 const userResponse = await vscode.window.showInformationMessage(
-                    `Language server binary for rust-analyzer was not found. ` +
-                    `Do you want to download it now?`,
+                    "Language server binary for rust-analyzer was not found. " +
+                    "Do you want to download it now?",
                     "Download now", "Cancel"
                 );
                 if (userResponse !== "Download now") return null;
@@ -101,7 +101,7 @@ export async function ensureLanguageServerBinary(
 
 
                 assert(
-                    isBinaryAvailable(bundledBinaryPath),
+                    isBinaryAvailable(prebuiltBinaryPath),
                     "Downloaded language server binary is not functional"
                 );
 
@@ -109,7 +109,7 @@ export async function ensureLanguageServerBinary(
                     "Rust analyzer language server was successfully installed 🦀"
                 );
             }
-            return bundledBinaryPath;
+            return prebuiltBinaryPath;
         }
     }
 
-- 
cgit v1.2.3


From a3e3fba7bf9cbaa51d39ecfd2b111472fdbf4cb3 Mon Sep 17 00:00:00 2001
From: Veetaha <veetaha2@gmail.com>
Date: Sun, 9 Feb 2020 12:54:51 +0200
Subject: vscode: fix chmod to octal literal

Co-Authored-By: Aleksey Kladov <aleksey.kladov@gmail.com>
---
 editors/code/src/installation/language_server.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index d09fc63a7..ea1228e46 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -48,7 +48,7 @@ export async function downloadLatestLanguageServer(
         }
     );
 
-    await fs.chmod(installationPath, 755); // Set (rwx, r_x, r_x) permissions
+    await fs.chmod(installationPath, 0o755); // Set (rwx, r_x, r_x) permissions
 }
 export async function ensureLanguageServerBinary(
     langServerSource: null | BinarySource
-- 
cgit v1.2.3


From 3159e87c49cd43677927ba7baa8f12c1232183a1 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 13:36:36 +0200
Subject: vscode: refactor levels of code nesting and string literals quotes

---
 editors/code/src/installation/language_server.ts | 56 +++++++++++++-----------
 1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index ea1228e46..e571cbc98 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -71,9 +71,10 @@ export async function ensureLanguageServerBinary(
             if (isBinaryAvailable(langServerSource.path)) {
                 return langServerSource.path;
             }
+
             vscode.window.showErrorMessage(
                 `Unable to run ${langServerSource.path} binary. ` +
-                "To use the pre-built language server, set `rust-analyzer.raLspServerPath` " +
+                `To use the pre-built language server, set "rust-analyzer.raLspServerPath" ` +
                 "value to `null` or remove it from the settings to use it by default."
             );
             return null;
@@ -81,34 +82,37 @@ export async function ensureLanguageServerBinary(
         case BinarySource.Type.GithubRelease: {
             const prebuiltBinaryPath = path.join(langServerSource.dir, langServerSource.file);
 
-            if (!isBinaryAvailable(prebuiltBinaryPath)) {
-                const userResponse = await vscode.window.showInformationMessage(
-                    "Language server binary for rust-analyzer was not found. " +
-                    "Do you want to download it now?",
-                    "Download now", "Cancel"
-                );
-                if (userResponse !== "Download now") return null;
-
-                try {
-                    await downloadLatestLanguageServer(langServerSource);
-                } catch (err) {
-                    await vscode.window.showErrorMessage(
-                        `Failed to download language server from ${langServerSource.repo.name} ` +
-                        `GitHub repository: ${err.message}`
-                    );
-                    return null;
-                }
-
-
-                assert(
-                    isBinaryAvailable(prebuiltBinaryPath),
-                    "Downloaded language server binary is not functional"
-                );
+            if (isBinaryAvailable(prebuiltBinaryPath)) {
+                return prebuiltBinaryPath;
+            }
 
-                vscode.window.showInformationMessage(
-                    "Rust analyzer language server was successfully installed 🦀"
+            const userResponse = await vscode.window.showInformationMessage(
+                "Language server binary for rust-analyzer was not found. " +
+                "Do you want to download it now?",
+                "Download now", "Cancel"
+            );
+            if (userResponse !== "Download now") return null;
+
+            try {
+                await downloadLatestLanguageServer(langServerSource);
+            } catch (err) {
+                await vscode.window.showErrorMessage(
+                    `Failed to download language server from ${langServerSource.repo.name} ` +
+                    `GitHub repository: ${err.message}`
                 );
+                return null;
             }
+
+
+            assert(
+                isBinaryAvailable(prebuiltBinaryPath),
+                "Downloaded language server binary is not functional"
+            );
+
+            vscode.window.showInformationMessage(
+                "Rust analyzer language server was successfully installed 🦀"
+            );
+
             return prebuiltBinaryPath;
         }
     }
-- 
cgit v1.2.3


From 34241b9af966208d73f37f1cdf7f862f2590d846 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 13:39:54 +0200
Subject: vscode: remove noise data fields declarations as per @matklad

---
 editors/code/src/installation/fetch_latest_artifact_metadata.ts | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/editors/code/src/installation/fetch_latest_artifact_metadata.ts b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
index cda955af2..f1019e089 100644
--- a/editors/code/src/installation/fetch_latest_artifact_metadata.ts
+++ b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
@@ -31,17 +31,12 @@ export async function fetchLatestArtifactMetadata(
         downloadUrl: artifact.browser_download_url
     };
 
-    // Noise denotes tremendous amount of data that we are not using here
+    // We omit declaration of tremendous amount of fields that we are not using here
     interface GithubRelease {
         name: string;
         assets: Array<{
             name: string;
             browser_download_url: string;
-
-            [noise: string]: unknown;
         }>;
-
-        [noise: string]: unknown;
     }
-
 }
-- 
cgit v1.2.3


From 7a09274e52dc00f7d4e3a040686aa1eb1e075671 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 13:45:06 +0200
Subject: vscode: refactor inverted ternaries to if statements as per @matklad

---
 editors/code/src/config.ts                                      | 4 +++-
 editors/code/src/installation/fetch_latest_artifact_metadata.ts | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 46394600b..d5f3da2ed 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -97,7 +97,9 @@ export class Config {
 
         const prebuiltBinaryName = Config.prebuiltLangServerFileName(process.platform);
 
-        return !prebuiltBinaryName ? null : {
+        if (!prebuiltBinaryName) return null;
+
+        return {
             type: BinarySource.Type.GithubRelease,
             dir: ctx.globalStoragePath,
             file: prebuiltBinaryName,
diff --git a/editors/code/src/installation/fetch_latest_artifact_metadata.ts b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
index f1019e089..9141c92ef 100644
--- a/editors/code/src/installation/fetch_latest_artifact_metadata.ts
+++ b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
@@ -26,7 +26,9 @@ export async function fetchLatestArtifactMetadata(
 
     const artifact = response.assets.find(artifact => artifact.name === artifactFileName);
 
-    return !artifact ? null : {
+    if (!artifact) return null;
+
+    return {
         releaseName: response.name,
         downloadUrl: artifact.browser_download_url
     };
-- 
cgit v1.2.3


From a63659badb75d22ad834b7524e77505790c10dd0 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 13:59:27 +0200
Subject: vscode: replaced unwrapNotNil() with ! as per @matklad

---
 editors/code/package-lock.json                   | 13 -------------
 editors/code/package.json                        |  1 -
 editors/code/src/installation/language_server.ts | 10 +++-------
 3 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index 1b7c8910e..5c056463e 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -753,19 +753,6 @@
                 "os-tmpdir": "~1.0.1"
             }
         },
-        "ts-not-nil": {
-            "version": "1.0.1",
-            "resolved": "https://registry.npmjs.org/ts-not-nil/-/ts-not-nil-1.0.1.tgz",
-            "integrity": "sha512-19+u+3okJddVZlrIdTOdFBaMsHYDInIGDPiujxfRa0RS2Ch5055zVG4GAqa+CZ/Rd1a+7ORSm8O4+2kesPymtw==",
-            "requires": {
-                "ts-typedefs": ">=3.2.0"
-            }
-        },
-        "ts-typedefs": {
-            "version": "3.2.0",
-            "resolved": "https://registry.npmjs.org/ts-typedefs/-/ts-typedefs-3.2.0.tgz",
-            "integrity": "sha512-NglEH2YiY40YxNAvwBISqqXRTKlQq6x+qoCF+tkjPxwrPbrkmq7V3LXavmxrD63fENtMhFkcqgMJtOirtow9iA=="
-        },
         "tslib": {
             "version": "1.10.0",
             "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.10.0.tgz",
diff --git a/editors/code/package.json b/editors/code/package.json
index c0a62619d..f687eb8d4 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -27,7 +27,6 @@
         "jsonc-parser": "^2.1.0",
         "node-fetch": "^2.6.0",
         "throttle-debounce": "^2.1.0",
-        "ts-not-nil": "^1.0.1",
         "vscode-languageclient": "^6.1.0"
     },
     "devDependencies": {
diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index e571cbc98..a169eae47 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -1,4 +1,3 @@
-import { unwrapNotNil } from "ts-not-nil";
 import { spawnSync } from "child_process";
 import * as vscode from "vscode";
 import * as path from "path";
@@ -12,12 +11,9 @@ import { downloadFile } from "./download_file";
 export async function downloadLatestLanguageServer(
     {file: artifactFileName, dir: installationDir, repo}: BinarySource.GithubRelease
 ) {
-    const binaryMetadata = await fetchLatestArtifactMetadata(repo, artifactFileName);
-
-    const {
-        releaseName,
-        downloadUrl
-    } = unwrapNotNil(binaryMetadata, `Latest GitHub release lacks "${artifactFileName}" file`);
+    const { releaseName, downloadUrl } = (await fetchLatestArtifactMetadata(
+        repo, artifactFileName
+    ))!;
 
     await fs.mkdir(installationDir).catch(err => assert.strictEqual(
         err?.code,
-- 
cgit v1.2.3


From f3240e22c6de69b408a83b59e85f40fb913acfab Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 14:18:05 +0200
Subject: vscode: move throtting of download progress to call site

---
 editors/code/src/installation/download_file.ts   |  8 +++----
 editors/code/src/installation/language_server.ts | 27 ++++++++++++++----------
 2 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/editors/code/src/installation/download_file.ts b/editors/code/src/installation/download_file.ts
index ec16dcd66..53bf46d78 100644
--- a/editors/code/src/installation/download_file.ts
+++ b/editors/code/src/installation/download_file.ts
@@ -1,20 +1,18 @@
 import fetch from "node-fetch";
-import { throttle } from "throttle-debounce";
 import * as fs from "fs";
 import { strict as assert } from "assert";
 
 /**
  * Downloads file from `url` and stores it at `destFilePath`.
- * `onProgress` callback is periodically called to track the progress of downloading,
- * it gets the already read and total amount of bytes to read as its parameters.
+ * `onProgress` callback is called on recieveing each chunk of bytes
+ * to track the progress of downloading, it gets the already read and total
+ * amount of bytes to read as its parameters.
  */
 export async function downloadFile(
     url: string,
     destFilePath: fs.PathLike,
     onProgress: (readBytes: number, totalBytes: number) => void
 ): Promise<void> {
-    onProgress = throttle(200, /* noTrailing: */ true, onProgress);
-
     const response = await fetch(url);
 
     const totalBytes = Number(response.headers.get('content-length'));
diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index a169eae47..c1f37f978 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -1,8 +1,9 @@
-import { spawnSync } from "child_process";
 import * as vscode from "vscode";
 import * as path from "path";
 import { strict as assert } from "assert";
 import { promises as fs } from "fs";
+import { spawnSync } from "child_process";
+import { throttle } from "throttle-debounce";
 
 import { BinarySource } from "./interfaces";
 import { fetchLatestArtifactMetadata } from "./fetch_latest_artifact_metadata";
@@ -28,19 +29,23 @@ export async function downloadLatestLanguageServer(
         {
             location: vscode.ProgressLocation.Notification,
             cancellable: false, // FIXME: add support for canceling download?
-            title: `Downloading language server ${releaseName}`
+            title: `Downloading language server (${releaseName})`
         },
         async (progress, _cancellationToken) => {
             let lastPrecentage = 0;
-            await downloadFile(downloadUrl, installationPath, (readBytes, totalBytes) => {
-                const newPercentage = (readBytes / totalBytes) * 100;
-                progress.report({
-                    message: newPercentage.toFixed(0) + "%",
-                    increment: newPercentage - lastPrecentage
-                });
-
-                lastPrecentage = newPercentage;
-            });
+            await downloadFile(downloadUrl, installationPath, throttle(
+                200,
+                /* noTrailing: */ true,
+                (readBytes, totalBytes) => {
+                    const newPercentage = (readBytes / totalBytes) * 100;
+                    progress.report({
+                        message: newPercentage.toFixed(0) + "%",
+                        increment: newPercentage - lastPrecentage
+                    });
+
+                    lastPrecentage = newPercentage;
+                })
+            );
         }
     );
 
-- 
cgit v1.2.3


From 7cba77ed4e4207b2e24b8dd57723368c2717bb2a Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 15:01:00 +0200
Subject: vscode: added logging when donloading binaries

---
 editors/code/src/installation/download_file.ts     |  2 ++
 .../installation/fetch_latest_artifact_metadata.ts |  2 ++
 editors/code/src/installation/language_server.ts   | 27 ++++++++++++++++++----
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/editors/code/src/installation/download_file.ts b/editors/code/src/installation/download_file.ts
index 53bf46d78..b51602ef9 100644
--- a/editors/code/src/installation/download_file.ts
+++ b/editors/code/src/installation/download_file.ts
@@ -20,6 +20,8 @@ export async function downloadFile(
 
     let readBytes = 0;
 
+    console.log("Downloading file of", totalBytes, "bytes size from", url, "to", destFilePath);
+
     return new Promise<void>((resolve, reject) => response.body
         .on("data", (chunk: Buffer) => {
             readBytes += chunk.length;
diff --git a/editors/code/src/installation/fetch_latest_artifact_metadata.ts b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
index 9141c92ef..7e3700603 100644
--- a/editors/code/src/installation/fetch_latest_artifact_metadata.ts
+++ b/editors/code/src/installation/fetch_latest_artifact_metadata.ts
@@ -19,6 +19,8 @@ export async function fetchLatestArtifactMetadata(
 
     // We skip runtime type checks for simplicity (here we cast from `any` to `GithubRelease`)
 
+    console.log("Issuing request for released artifacts metadata to", requestUrl);
+
     const response: GithubRelease = await fetch(requestUrl, {
             headers: { Accept: "application/vnd.github.v3+json" }
         })
diff --git a/editors/code/src/installation/language_server.ts b/editors/code/src/installation/language_server.ts
index c1f37f978..1ce67b8b2 100644
--- a/editors/code/src/installation/language_server.ts
+++ b/editors/code/src/installation/language_server.ts
@@ -2,6 +2,7 @@ import * as vscode from "vscode";
 import * as path from "path";
 import { strict as assert } from "assert";
 import { promises as fs } from "fs";
+import { promises as dns } from "dns";
 import { spawnSync } from "child_process";
 import { throttle } from "throttle-debounce";
 
@@ -25,6 +26,7 @@ export async function downloadLatestLanguageServer(
 
     const installationPath = path.join(installationDir, artifactFileName);
 
+    console.time("Downloading ra_lsp_server");
     await vscode.window.withProgress(
         {
             location: vscode.ProgressLocation.Notification,
@@ -48,6 +50,7 @@ export async function downloadLatestLanguageServer(
             );
         }
     );
+    console.timeEnd("Downloading ra_lsp_server");
 
     await fs.chmod(installationPath, 0o755); // Set (rwx, r_x, r_x) permissions
 }
@@ -101,15 +104,21 @@ export async function ensureLanguageServerBinary(
                     `Failed to download language server from ${langServerSource.repo.name} ` +
                     `GitHub repository: ${err.message}`
                 );
+
+                await dns.resolve('www.google.com').catch(err => {
+                    console.error("DNS resolution failed, there might be an issue with Internet availability");
+                    console.error(err);
+                });
+
                 return null;
             }
 
-
-            assert(
-                isBinaryAvailable(prebuiltBinaryPath),
-                "Downloaded language server binary is not functional"
+            if (!isBinaryAvailable(prebuiltBinaryPath)) assert(false,
+                `Downloaded language server binary is not functional.` +
+                `Downloaded from: ${JSON.stringify(langServerSource)}`
             );
 
+
             vscode.window.showInformationMessage(
                 "Rust analyzer language server was successfully installed 🦀"
             );
@@ -119,6 +128,14 @@ export async function ensureLanguageServerBinary(
     }
 
     function isBinaryAvailable(binaryPath: string) {
-        return spawnSync(binaryPath, ["--version"]).status === 0;
+        const res = spawnSync(binaryPath, ["--version"]);
+
+        // ACHTUNG! `res` type declaration is inherently wrong, see
+        // https://github.com/DefinitelyTyped/DefinitelyTyped/issues/42221
+
+        console.log("Checked binary availablity via --version", res);
+        console.log(binaryPath, "--version output:", res.output?.map(String));
+
+        return res.status === 0;
     }
 }
-- 
cgit v1.2.3


From 6a367886ece53e12d62394fe676c9476b4343933 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 15:51:28 +0200
Subject: vscode: updated docs on prebuilt binaries

---
 docs/user/README.md | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/docs/user/README.md b/docs/user/README.md
index 18867cd11..abf7c013b 100644
--- a/docs/user/README.md
+++ b/docs/user/README.md
@@ -32,6 +32,37 @@ a minimum version of 10 installed. Please refer to
 You will also need the most recent version of VS Code: we don't try to
 maintain compatibility with older versions yet.
 
+### Installation from prebuilt binaries
+
+We ship prebuilt binaries for Linux, Mac and Windows via
+[GitHub releases](https://github.com/rust-analyzer/rust-analyzer/releases).
+In order to use them you need to install the client VSCode extension.
+
+Publishing to VSCode marketplace is currently WIP. Thus you need to clone the repository and install **only** the client extension via
+```
+$ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
+$ cd rust-analyzer
+$ cargo xtask install --client-code
+```
+Then open VSCode (or reload the window if it was already running), open some Rust project and you should
+see an info message pop-up.
+
+
+<img height="140px" src="https://user-images.githubusercontent.com/36276403/74103174-a40df100-4b52-11ea-81f4-372c70797924.png" alt="Download now message"/>
+
+
+Click `Download now`, wait untill the progress is 100% and you are ready to go.
+
+For updates you need to remove installed binary
+```
+rm -rf ${HOME}/.config/Code/User/globalStorage/matklad.rust-analyzer
+```
+
+`"Donwload latest language server"` command for VSCode and automatic updates detection is currently WIP.
+
+
+### Installation from sources
+
 The experimental VS Code plugin can then be built and installed by executing the
 following commands:
 
@@ -47,6 +78,7 @@ doesn't, report bugs!
 **Note** [#1831](https://github.com/rust-analyzer/rust-analyzer/issues/1831): If you are using the popular
 [Vim emulation plugin](https://github.com/VSCodeVim/Vim), you will likely
 need to turn off the `rust-analyzer.enableEnhancedTyping` setting.
+(// TODO: This configuration is no longer available, enhanced typing shoud be disabled via removing Enter key binding, [see this issue](https://github.com/rust-analyzer/rust-analyzer/issues/3051))
 
 If you have an unusual setup (for example, `code` is not in the `PATH`), you
 should adapt these manual installation instructions:
-- 
cgit v1.2.3


From be244ab2fb243e945c7024da06c801fb3774b753 Mon Sep 17 00:00:00 2001
From: Veetaha <gerzoh1@gmail.com>
Date: Sun, 9 Feb 2020 15:54:54 +0200
Subject: docs: minor fixes in wordings and punctuation

---
 docs/user/README.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/user/README.md b/docs/user/README.md
index abf7c013b..a60990ca8 100644
--- a/docs/user/README.md
+++ b/docs/user/README.md
@@ -38,7 +38,7 @@ We ship prebuilt binaries for Linux, Mac and Windows via
 [GitHub releases](https://github.com/rust-analyzer/rust-analyzer/releases).
 In order to use them you need to install the client VSCode extension.
 
-Publishing to VSCode marketplace is currently WIP. Thus you need to clone the repository and install **only** the client extension via
+Publishing to VSCode marketplace is currently WIP. Thus, you need to clone the repository and install **only** the client extension via
 ```
 $ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
 $ cd rust-analyzer
@@ -63,7 +63,7 @@ rm -rf ${HOME}/.config/Code/User/globalStorage/matklad.rust-analyzer
 
 ### Installation from sources
 
-The experimental VS Code plugin can then be built and installed by executing the
+The experimental VS Code plugin can be built and installed by executing the
 following commands:
 
 ```
-- 
cgit v1.2.3


From dfb81a8cd4b9a2efd8151b4ac36105c51df7d683 Mon Sep 17 00:00:00 2001
From: Veetaha <veetaha2@gmail.com>
Date: Sun, 9 Feb 2020 17:04:33 +0200
Subject: docs: fix spelling untill -> until

Co-Authored-By: Jonas Platte <jplatte@users.noreply.github.com>
---
 docs/user/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/user/README.md b/docs/user/README.md
index a60990ca8..082dadd76 100644
--- a/docs/user/README.md
+++ b/docs/user/README.md
@@ -51,7 +51,7 @@ see an info message pop-up.
 <img height="140px" src="https://user-images.githubusercontent.com/36276403/74103174-a40df100-4b52-11ea-81f4-372c70797924.png" alt="Download now message"/>
 
 
-Click `Download now`, wait untill the progress is 100% and you are ready to go.
+Click `Download now`, wait until the progress is 100% and you are ready to go.
 
 For updates you need to remove installed binary
 ```
-- 
cgit v1.2.3