15 files changed, 240 insertions, 280 deletions

diff --git a/editors/code/package.json b/editors/code/package.json
index 6662747f6..46d55e32d 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -19,7 +19,7 @@
         "vscode:prepublish": "rollup -c",
         "package": "vsce package",
         "watch": "tsc -watch -p ./",
-        "prettier": "prettier --write **/*.ts"
+        "prettier": "prettier --write '**/*.ts'"
     },
     "dependencies": {
         "jsonc-parser": "^2.1.0",
diff --git a/editors/code/src/commands/analyzer_status.ts b/editors/code/src/commands/analyzer_status.ts
index c9d32fe07..b2b624b75 100644
--- a/editors/code/src/commands/analyzer_status.ts
+++ b/editors/code/src/commands/analyzer_status.ts
@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+
 import { Ctx, Cmd } from '../ctx';
 // Shows status of rust-analyzer (for debugging)
 
@@ -23,10 +24,7 @@ export function analyzerStatus(ctx: Ctx): Cmd {
 
     return async function handle() {
         if (poller == null) {
-            poller = setInterval(
-                () => tdcp.eventEmitter.fire(tdcp.uri),
-                1000,
-            );
+            poller = setInterval(() => tdcp.eventEmitter.fire(tdcp.uri), 1000);
         }
         const document = await vscode.workspace.openTextDocument(tdcp.uri);
         return vscode.window.showTextDocument(
@@ -39,23 +37,20 @@ export function analyzerStatus(ctx: Ctx): Cmd {
 
 class TextDocumentContentProvider
     implements vscode.TextDocumentContentProvider {
-
+    ctx: Ctx;
     uri = vscode.Uri.parse('rust-analyzer-status://status');
     eventEmitter = new vscode.EventEmitter<vscode.Uri>();
 
-    ctx: Ctx
-
     constructor(ctx: Ctx) {
-        this.ctx = ctx
+        this.ctx = ctx;
     }
 
     provideTextDocumentContent(
         _uri: vscode.Uri,
     ): vscode.ProviderResult<string> {
         const editor = vscode.window.activeTextEditor;
-        if (editor == null) {
-            return '';
-        }
+        if (editor == null) return '';
+
         return this.ctx.client.sendRequest<string>(
             'rust-analyzer/analyzerStatus',
             null,
diff --git a/editors/code/src/commands/index.ts b/editors/code/src/commands/index.ts
index 9d9b9c575..8f91b3b7d 100644
--- a/editors/code/src/commands/index.ts
+++ b/editors/code/src/commands/index.ts
@@ -1,23 +1,23 @@
-import { Ctx, Cmd } from '../ctx'
+import { Ctx, Cmd } from '../ctx';
 
 import { analyzerStatus } from './analyzer_status';
 import { matchingBrace } from './matching_brace';
-import * as applySourceChange from './apply_source_change';
+import { joinLines } from './join_lines';
+import { onEnter } from './on_enter';
+import { parentModule } from './parent_module';
+import { syntaxTree } from './syntax_tree';
 import * as expandMacro from './expand_macro';
 import * as inlayHints from './inlay_hints';
-import * as joinLines from './join_lines';
-import * as onEnter from './on_enter';
-import * as parentModule from './parent_module';
 import * as runnables from './runnables';
-import * as syntaxTree from './syntaxTree';
 
 function collectGarbage(ctx: Ctx): Cmd {
-    return async () => { ctx.client.sendRequest<null>('rust-analyzer/collectGarbage', null) }
+    return async () => {
+        ctx.client.sendRequest<null>('rust-analyzer/collectGarbage', null);
+    };
 }
 
 export {
     analyzerStatus,
-    applySourceChange,
     expandMacro,
     joinLines,
     matchingBrace,
@@ -26,5 +26,5 @@ export {
     syntaxTree,
     onEnter,
     inlayHints,
-    collectGarbage
+    collectGarbage,
 };
diff --git a/editors/code/src/commands/join_lines.ts b/editors/code/src/commands/join_lines.ts
index 134ddc801..f4f902cf9 100644
--- a/editors/code/src/commands/join_lines.ts
+++ b/editors/code/src/commands/join_lines.ts
@@ -1,29 +1,26 @@
-import * as vscode from 'vscode';
+import * as lc from 'vscode-languageclient';
 
-import { Range, TextDocumentIdentifier } from 'vscode-languageclient';
-import { Server } from '../server';
-import {
-    handle as applySourceChange,
-    SourceChange,
-} from './apply_source_change';
+import { Ctx, Cmd } from '../ctx';
+import { applySourceChange, SourceChange } from '../source_change';
 
-interface JoinLinesParams {
-    textDocument: TextDocumentIdentifier;
-    range: Range;
-}
+export function joinLines(ctx: Ctx): Cmd {
+    return async () => {
+        const editor = ctx.activeRustEditor;
+        if (!editor) return;
 
-export async function handle() {
-    const editor = vscode.window.activeTextEditor;
-    if (editor == null || editor.document.languageId !== 'rust') {
-        return;
-    }
-    const request: JoinLinesParams = {
-        range: Server.client.code2ProtocolConverter.asRange(editor.selection),
-        textDocument: { uri: editor.document.uri.toString() },
+        const request: JoinLinesParams = {
+            range: ctx.client.code2ProtocolConverter.asRange(editor.selection),
+            textDocument: { uri: editor.document.uri.toString() },
+        };
+        const change = await ctx.client.sendRequest<SourceChange>(
+            'rust-analyzer/joinLines',
+            request,
+        );
+        await applySourceChange(ctx, change);
     };
-    const change = await Server.client.sendRequest<SourceChange>(
-        'rust-analyzer/joinLines',
-        request,
-    );
-    await applySourceChange(change);
+}
+
+interface JoinLinesParams {
+    textDocument: lc.TextDocumentIdentifier;
+    range: lc.Range;
 }
diff --git a/editors/code/src/commands/matching_brace.ts b/editors/code/src/commands/matching_brace.ts
index 665b0c33c..59c253f88 100644
--- a/editors/code/src/commands/matching_brace.ts
+++ b/editors/code/src/commands/matching_brace.ts
@@ -1,5 +1,6 @@
 import * as vscode from 'vscode';
-import { Position, TextDocumentIdentifier } from 'vscode-languageclient';
+import * as lc from 'vscode-languageclient';
+
 import { Ctx, Cmd } from '../ctx';
 
 export function matchingBrace(ctx: Ctx): Cmd {
@@ -10,9 +11,11 @@ export function matchingBrace(ctx: Ctx): Cmd {
         }
         const request: FindMatchingBraceParams = {
             textDocument: { uri: editor.document.uri.toString() },
-            offsets: editor.selections.map(s => ctx.client.code2ProtocolConverter.asPosition(s.active)),
+            offsets: editor.selections.map(s =>
+                ctx.client.code2ProtocolConverter.asPosition(s.active),
+            ),
         };
-        const response = await ctx.client.sendRequest<Position[]>(
+        const response = await ctx.client.sendRequest<lc.Position[]>(
             'rust-analyzer/findMatchingBrace',
             request,
         );
@@ -24,10 +27,10 @@ export function matchingBrace(ctx: Ctx): Cmd {
             return new vscode.Selection(anchor, active);
         });
         editor.revealRange(editor.selection);
-    }
+    };
 }
 
 interface FindMatchingBraceParams {
-    textDocument: TextDocumentIdentifier;
-    offsets: Position[];
+    textDocument: lc.TextDocumentIdentifier;
+    offsets: lc.Position[];
 }
diff --git a/editors/code/src/commands/on_enter.ts b/editors/code/src/commands/on_enter.ts
index 772c64b3c..8324060e8 100644
--- a/editors/code/src/commands/on_enter.ts
+++ b/editors/code/src/commands/on_enter.ts
@@ -1,33 +1,26 @@
-import * as vscode from 'vscode';
 import * as lc from 'vscode-languageclient';
-import { Server } from '../server';
-import {
-    handle as applySourceChange,
-    SourceChange,
-} from './apply_source_change';
 
-export async function handle(event: { text: string }): Promise<boolean> {
-    const editor = vscode.window.activeTextEditor;
-    if (
-        editor == null ||
-        editor.document.languageId !== 'rust' ||
-        event.text !== '\n'
-    ) {
-        return false;
-    }
-    const request: lc.TextDocumentPositionParams = {
-        textDocument: { uri: editor.document.uri.toString() },
-        position: Server.client.code2ProtocolConverter.asPosition(
-            editor.selection.active,
-        ),
+import { applySourceChange, SourceChange } from '../source_change';
+import { Cmd, Ctx } from '../ctx';
+
+export function onEnter(ctx: Ctx): Cmd {
+    return async (event: { text: string }) => {
+        const editor = ctx.activeRustEditor;
+        if (!editor || event.text !== '\n') return false;
+
+        const request: lc.TextDocumentPositionParams = {
+            textDocument: { uri: editor.document.uri.toString() },
+            position: ctx.client.code2ProtocolConverter.asPosition(
+                editor.selection.active,
+            ),
+        };
+        const change = await ctx.client.sendRequest<undefined | SourceChange>(
+            'rust-analyzer/onEnter',
+            request,
+        );
+        if (!change) return false;
+
+        await applySourceChange(ctx, change);
+        return true;
     };
-    const change = await Server.client.sendRequest<undefined | SourceChange>(
-        'rust-analyzer/onEnter',
-        request,
-    );
-    if (!change) {
-        return false;
-    }
-    await applySourceChange(change);
-    return true;
 }
diff --git a/editors/code/src/commands/parent_module.ts b/editors/code/src/commands/parent_module.ts
index ad49e1bdb..258b61b21 100644
--- a/editors/code/src/commands/parent_module.ts
+++ b/editors/code/src/commands/parent_module.ts
@@ -1,32 +1,32 @@
 import * as vscode from 'vscode';
-
 import * as lc from 'vscode-languageclient';
-import { Server } from '../server';
 
-export async function handle() {
-    const editor = vscode.window.activeTextEditor;
-    if (editor == null || editor.document.languageId !== 'rust') {
-        return;
-    }
-    const request: lc.TextDocumentPositionParams = {
-        textDocument: { uri: editor.document.uri.toString() },
-        position: Server.client.code2ProtocolConverter.asPosition(
-            editor.selection.active,
-        ),
-    };
-    const response = await Server.client.sendRequest<lc.Location[]>(
-        'rust-analyzer/parentModule',
-        request,
-    );
-    const loc = response[0];
-    if (loc == null) {
-        return;
-    }
-    const uri = Server.client.protocol2CodeConverter.asUri(loc.uri);
-    const range = Server.client.protocol2CodeConverter.asRange(loc.range);
+import { Ctx, Cmd } from '../ctx';
+
+export function parentModule(ctx: Ctx): Cmd {
+    return async () => {
+        const editor = ctx.activeRustEditor;
+        if (!editor) return;
 
-    const doc = await vscode.workspace.openTextDocument(uri);
-    const e = await vscode.window.showTextDocument(doc);
-    e.selection = new vscode.Selection(range.start, range.start);
-    e.revealRange(range, vscode.TextEditorRevealType.InCenter);
+        const request: lc.TextDocumentPositionParams = {
+            textDocument: { uri: editor.document.uri.toString() },
+            position: ctx.client.code2ProtocolConverter.asPosition(
+                editor.selection.active,
+            ),
+        };
+        const response = await ctx.client.sendRequest<lc.Location[]>(
+            'rust-analyzer/parentModule',
+            request,
+        );
+        const loc = response[0];
+        if (loc == null) return;
+
+        const uri = ctx.client.protocol2CodeConverter.asUri(loc.uri);
+        const range = ctx.client.protocol2CodeConverter.asRange(loc.range);
+
+        const doc = await vscode.workspace.openTextDocument(uri);
+        const e = await vscode.window.showTextDocument(doc);
+        e.selection = new vscode.Selection(range.start, range.start);
+        e.revealRange(range, vscode.TextEditorRevealType.InCenter);
+    };
 }
diff --git a/editors/code/src/commands/syntaxTree.ts b/editors/code/src/commands/syntaxTree.ts
deleted file mode 100644
index 89a80550c..000000000
--- a/editors/code/src/commands/syntaxTree.ts
+++ /dev/null
@@ -1,76 +0,0 @@
-import * as vscode from 'vscode';
-import { Range, TextDocumentIdentifier } from 'vscode-languageclient';
-
-import { Server } from '../server';
-
-export const syntaxTreeUri = vscode.Uri.parse('rust-analyzer://syntaxtree');
-
-export class SyntaxTreeContentProvider
-    implements vscode.TextDocumentContentProvider {
-    public eventEmitter = new vscode.EventEmitter<vscode.Uri>();
-    public syntaxTree: string = 'Not available';
-
-    public provideTextDocumentContent(
-        uri: vscode.Uri,
-    ): vscode.ProviderResult<string> {
-        const editor = vscode.window.activeTextEditor;
-        if (editor == null) {
-            return '';
-        }
-
-        let range: Range | undefined;
-
-        // When the range based query is enabled we take the range of the selection
-        if (uri.query === 'range=true') {
-            range = editor.selection.isEmpty
-                ? undefined
-                : Server.client.code2ProtocolConverter.asRange(
-                      editor.selection,
-                  );
-        }
-
-        const request: SyntaxTreeParams = {
-            textDocument: { uri: editor.document.uri.toString() },
-            range,
-        };
-        return Server.client.sendRequest<SyntaxTreeResult>(
-            'rust-analyzer/syntaxTree',
-            request,
-        );
-    }
-
-    get onDidChange(): vscode.Event<vscode.Uri> {
-        return this.eventEmitter.event;
-    }
-}
-
-interface SyntaxTreeParams {
-    textDocument: TextDocumentIdentifier;
-    range?: Range;
-}
-
-type SyntaxTreeResult = string;
-
-// Opens the virtual file that will show the syntax tree
-//
-// The contents of the file come from the `TextDocumentContentProvider`
-export function createHandle(provider: SyntaxTreeContentProvider) {
-    return async () => {
-        const editor = vscode.window.activeTextEditor;
-        const rangeEnabled = !!(editor && !editor.selection.isEmpty);
-
-        const uri = rangeEnabled
-            ? vscode.Uri.parse(`${syntaxTreeUri.toString()}?range=true`)
-            : syntaxTreeUri;
-
-        const document = await vscode.workspace.openTextDocument(uri);
-
-        provider.eventEmitter.fire(uri);
-
-        return vscode.window.showTextDocument(
-            document,
-            vscode.ViewColumn.Two,
-            true,
-        );
-    };
-}
diff --git a/editors/code/src/commands/syntax_tree.ts b/editors/code/src/commands/syntax_tree.ts
new file mode 100644
index 000000000..e61fb36df
--- /dev/null
+++ b/editors/code/src/commands/syntax_tree.ts
@@ -0,0 +1,106 @@
+import * as vscode from 'vscode';
+import * as lc from 'vscode-languageclient';
+
+import { Ctx, Cmd } from '../ctx';
+
+// Opens the virtual file that will show the syntax tree
+//
+// The contents of the file come from the `TextDocumentContentProvider`
+export function syntaxTree(ctx: Ctx): Cmd {
+    const stcp = new SyntaxTreeContentProvider(ctx);
+
+    ctx.pushCleanup(
+        vscode.workspace.registerTextDocumentContentProvider(
+            'rust-analyzer',
+            stcp,
+        ),
+    );
+
+    vscode.workspace.onDidChangeTextDocument(
+        (event: vscode.TextDocumentChangeEvent) => {
+            const doc = event.document;
+            if (doc.languageId !== 'rust') return;
+            afterLs(() => stcp.eventEmitter.fire(stcp.uri));
+        },
+        ctx.subscriptions,
+    );
+
+    vscode.window.onDidChangeActiveTextEditor(
+        (editor: vscode.TextEditor | undefined) => {
+            if (!editor || editor.document.languageId !== 'rust') return;
+            stcp.eventEmitter.fire(stcp.uri);
+        },
+        ctx.subscriptions,
+    );
+
+    return async () => {
+        const editor = vscode.window.activeTextEditor;
+        const rangeEnabled = !!(editor && !editor.selection.isEmpty);
+
+        const uri = rangeEnabled
+            ? vscode.Uri.parse(`${stcp.uri.toString()}?range=true`)
+            : stcp.uri;
+
+        const document = await vscode.workspace.openTextDocument(uri);
+
+        stcp.eventEmitter.fire(uri);
+
+        return vscode.window.showTextDocument(
+            document,
+            vscode.ViewColumn.Two,
+            true,
+        );
+    };
+}
+
+// We need to order this after LS updates, but there's no API for that.
+// Hence, good old setTimeout.
+function afterLs(f: () => any) {
+    setTimeout(f, 10);
+}
+
+interface SyntaxTreeParams {
+    textDocument: lc.TextDocumentIdentifier;
+    range?: lc.Range;
+}
+
+export class SyntaxTreeContentProvider
+    implements vscode.TextDocumentContentProvider {
+    ctx: Ctx;
+    uri = vscode.Uri.parse('rust-analyzer://syntaxtree');
+    eventEmitter = new vscode.EventEmitter<vscode.Uri>();
+    syntaxTree: string = 'Not available';
+
+    constructor(ctx: Ctx) {
+        this.ctx = ctx;
+    }
+
+    provideTextDocumentContent(uri: vscode.Uri): vscode.ProviderResult<string> {
+        const editor = vscode.window.activeTextEditor;
+        if (editor == null) return '';
+
+        let range: lc.Range | undefined;
+
+        // When the range based query is enabled we take the range of the selection
+        if (uri.query === 'range=true') {
+            range = editor.selection.isEmpty
+                ? undefined
+                : this.ctx.client.code2ProtocolConverter.asRange(
+                      editor.selection,
+                  );
+        }
+
+        const request: SyntaxTreeParams = {
+            textDocument: { uri: editor.document.uri.toString() },
+            range,
+        };
+        return this.ctx.client.sendRequest<string>(
+            'rust-analyzer/syntaxTree',
+            request,
+        );
+    }
+
+    get onDidChange(): vscode.Event<vscode.Uri> {
+        return this.eventEmitter.event;
+    }
+}
diff --git a/editors/code/src/ctx.ts b/editors/code/src/ctx.ts
index 712337fe7..c3a3583b5 100644
--- a/editors/code/src/ctx.ts
+++ b/editors/code/src/ctx.ts
@@ -27,6 +27,32 @@ export class Ctx {
         this.pushCleanup(d);
     }
 
+    overrideCommand(name: string, factory: (ctx: Ctx) => Cmd) {
+        const defaultCmd = `default:${name}`;
+        const override = factory(this);
+        const original = (...args: any[]) =>
+            vscode.commands.executeCommand(defaultCmd, ...args);
+        try {
+            const d = vscode.commands.registerCommand(
+                name,
+                async (...args: any[]) => {
+                    if (!(await override(...args))) {
+                        return await original(...args);
+                    }
+                },
+            );
+            this.pushCleanup(d);
+        } catch (_) {
+            vscode.window.showWarningMessage(
+                'Enhanced typing feature is disabled because of incompatibility with VIM extension, consider turning off rust-analyzer.enableEnhancedTyping: https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/README.md#settings',
+            );
+        }
+    }
+
+    get subscriptions(): { dispose(): any }[] {
+        return this.extCtx.subscriptions;
+    }
+
     pushCleanup(d: { dispose(): any }) {
         this.extCtx.subscriptions.push(d);
     }
diff --git a/editors/code/src/events/change_active_text_editor.ts b/editors/code/src/events/change_active_text_editor.ts
index 74b91bd48..4384ee567 100644
--- a/editors/code/src/events/change_active_text_editor.ts
+++ b/editors/code/src/events/change_active_text_editor.ts
@@ -1,21 +1,14 @@
 import { TextEditor } from 'vscode';
 import { TextDocumentIdentifier } from 'vscode-languageclient';
-
-import {
-    SyntaxTreeContentProvider,
-    syntaxTreeUri,
-} from '../commands/syntaxTree';
 import { Decoration } from '../highlighting';
 import { Server } from '../server';
 
-export function makeHandler(syntaxTreeProvider: SyntaxTreeContentProvider) {
+export function makeHandler() {
     return async function handle(editor: TextEditor | undefined) {
         if (!editor || editor.document.languageId !== 'rust') {
             return;
         }
 
-        syntaxTreeProvider.eventEmitter.fire(syntaxTreeUri);
-
         if (!Server.config.highlightingOn) {
             return;
         }
diff --git a/editors/code/src/events/change_text_document.ts b/editors/code/src/events/change_text_document.ts
deleted file mode 100644
index 2e998e889..000000000
--- a/editors/code/src/events/change_text_document.ts
+++ /dev/null
@@ -1,24 +0,0 @@
-import * as vscode from 'vscode';
-
-import {
-    SyntaxTreeContentProvider,
-    syntaxTreeUri,
-} from '../commands/syntaxTree';
-
-export function createHandler(syntaxTreeProvider: SyntaxTreeContentProvider) {
-    return (event: vscode.TextDocumentChangeEvent) => {
-        const doc = event.document;
-        if (doc.languageId !== 'rust') {
-            return;
-        }
-        afterLs(() => {
-            syntaxTreeProvider.eventEmitter.fire(syntaxTreeUri);
-        });
-    };
-}
-
-// We need to order this after LS updates, but there's no API for that.
-// Hence, good old setTimeout.
-function afterLs(f: () => any) {
-    setTimeout(f, 10);
-}
diff --git a/editors/code/src/events/index.ts b/editors/code/src/events/index.ts
index 4c154563f..be135474d 100644
--- a/editors/code/src/events/index.ts
+++ b/editors/code/src/events/index.ts
@@ -1,4 +1,3 @@
 import * as changeActiveTextEditor from './change_active_text_editor';
-import * as changeTextDocument from './change_text_document';
 
-export { changeActiveTextEditor, changeTextDocument };
+export { changeActiveTextEditor };
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index a4149a059..d92cd164f 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -4,7 +4,6 @@ import * as lc from 'vscode-languageclient';
 import * as commands from './commands';
 import { ExpandMacroContentProvider } from './commands/expand_macro';
 import { HintsUpdater } from './commands/inlay_hints';
-import { SyntaxTreeContentProvider } from './commands/syntaxTree';
 import { StatusDisplay } from './commands/watch_status';
 import * as events from './events';
 import * as notifications from './notifications';
@@ -18,6 +17,9 @@ export async function activate(context: vscode.ExtensionContext) {
     ctx.registerCommand('analyzerStatus', commands.analyzerStatus);
     ctx.registerCommand('collectGarbage', commands.collectGarbage);
     ctx.registerCommand('matchingBrace', commands.matchingBrace);
+    ctx.registerCommand('joinLines', commands.joinLines);
+    ctx.registerCommand('parentModule', commands.parentModule);
+    ctx.registerCommand('syntaxTree', commands.syntaxTree);
 
     function disposeOnDeactivation(disposable: vscode.Disposable) {
         context.subscriptions.push(disposable);
@@ -26,46 +28,12 @@ export async function activate(context: vscode.ExtensionContext) {
     function registerCommand(name: string, f: any) {
         disposeOnDeactivation(vscode.commands.registerCommand(name, f));
     }
-    function overrideCommand(
-        name: string,
-        f: (...args: any[]) => Promise<boolean>,
-    ) {
-        const defaultCmd = `default:${name}`;
-        const original = (...args: any[]) =>
-            vscode.commands.executeCommand(defaultCmd, ...args);
-
-        try {
-            registerCommand(name, async (...args: any[]) => {
-                const editor = vscode.window.activeTextEditor;
-                if (
-                    !editor ||
-                    !editor.document ||
-                    editor.document.languageId !== 'rust'
-                ) {
-                    return await original(...args);
-                }
-                if (!(await f(...args))) {
-                    return await original(...args);
-                }
-            });
-        } catch (_) {
-            vscode.window.showWarningMessage(
-                'Enhanced typing feature is disabled because of incompatibility with VIM extension, consider turning off rust-analyzer.enableEnhancedTyping: https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/README.md#settings',
-            );
-        }
-    }
 
     // Commands are requests from vscode to the language server
-    registerCommand('rust-analyzer.joinLines', commands.joinLines.handle);
-    registerCommand('rust-analyzer.parentModule', commands.parentModule.handle);
     registerCommand('rust-analyzer.run', commands.runnables.handle);
     // Unlike the above this does not send requests to the language server
     registerCommand('rust-analyzer.runSingle', commands.runnables.handleSingle);
     registerCommand(
-        'rust-analyzer.applySourceChange',
-        commands.applySourceChange.handle,
-    );
-    registerCommand(
         'rust-analyzer.showReferences',
         (uri: string, position: lc.Position, locations: lc.Location[]) => {
             vscode.commands.executeCommand(
@@ -78,7 +46,7 @@ export async function activate(context: vscode.ExtensionContext) {
     );
 
     if (Server.config.enableEnhancedTyping) {
-        overrideCommand('type', commands.onEnter.handle);
+        ctx.overrideCommand('type', commands.onEnter);
     }
 
     const watchStatus = new StatusDisplay(
@@ -87,10 +55,7 @@ export async function activate(context: vscode.ExtensionContext) {
     disposeOnDeactivation(watchStatus);
 
     // Notifications are events triggered by the language server
-    const allNotifications: Iterable<[
-        string,
-        lc.GenericNotificationHandler,
-    ]> = [
+    const allNotifications: [string, lc.GenericNotificationHandler][] = [
         [
             'rust-analyzer/publishDecorations',
             notifications.publishDecorations.handle,
@@ -100,42 +65,25 @@ export async function activate(context: vscode.ExtensionContext) {
             params => watchStatus.handleProgressNotification(params),
         ],
     ];
-    const syntaxTreeContentProvider = new SyntaxTreeContentProvider();
     const expandMacroContentProvider = new ExpandMacroContentProvider();
 
     // The events below are plain old javascript events, triggered and handled by vscode
     vscode.window.onDidChangeActiveTextEditor(
-        events.changeActiveTextEditor.makeHandler(syntaxTreeContentProvider),
+        events.changeActiveTextEditor.makeHandler(),
     );
 
     disposeOnDeactivation(
         vscode.workspace.registerTextDocumentContentProvider(
             'rust-analyzer',
-            syntaxTreeContentProvider,
-        ),
-    );
-    disposeOnDeactivation(
-        vscode.workspace.registerTextDocumentContentProvider(
-            'rust-analyzer',
             expandMacroContentProvider,
         ),
     );
 
     registerCommand(
-        'rust-analyzer.syntaxTree',
-        commands.syntaxTree.createHandle(syntaxTreeContentProvider),
-    );
-    registerCommand(
         'rust-analyzer.expandMacro',
         commands.expandMacro.createHandle(expandMacroContentProvider),
     );
 
-    vscode.workspace.onDidChangeTextDocument(
-        events.changeTextDocument.createHandler(syntaxTreeContentProvider),
-        null,
-        context.subscriptions,
-    );
-
     const startServer = () => Server.start(allNotifications);
     const reloadCommand = () => reloadServer(startServer);
 
diff --git a/editors/code/src/commands/apply_source_change.ts b/editors/code/src/source_change.ts
index 8167398b1..a4f9068b2 100644
--- a/editors/code/src/commands/apply_source_change.ts
+++ b/editors/code/src/source_change.ts
@@ -1,7 +1,7 @@
 import * as vscode from 'vscode';
 import * as lc from 'vscode-languageclient';
 
-import { Server } from '../server';
+import { Ctx } from './ctx';
 
 export interface SourceChange {
     label: string;
@@ -9,8 +9,8 @@ export interface SourceChange {
     cursorPosition?: lc.TextDocumentPositionParams;
 }
 
-export async function handle(change: SourceChange) {
-    const wsEdit = Server.client.protocol2CodeConverter.asWorkspaceEdit(
+export async function applySourceChange(ctx: Ctx, change: SourceChange) {
+    const wsEdit = ctx.client.protocol2CodeConverter.asWorkspaceEdit(
         change.workspaceEdit,
     );
     let created;
@@ -32,10 +32,10 @@ export async function handle(change: SourceChange) {
         const doc = await vscode.workspace.openTextDocument(toOpenUri);
         await vscode.window.showTextDocument(doc);
     } else if (toReveal) {
-        const uri = Server.client.protocol2CodeConverter.asUri(
+        const uri = ctx.client.protocol2CodeConverter.asUri(
             toReveal.textDocument.uri,
         );
-        const position = Server.client.protocol2CodeConverter.asPosition(
+        const position = ctx.client.protocol2CodeConverter.asPosition(
             toReveal.position,
         );
         const editor = vscode.window.activeTextEditor;