1 files changed, 106 insertions, 0 deletions

diff --git a/editors/code/src/cargo.ts b/editors/code/src/cargo.ts
new file mode 100644
index 000000000..a328ba9bd
--- /dev/null
+++ b/editors/code/src/cargo.ts
@@ -0,0 +1,106 @@
+import * as cp from 'child_process';
+import * as readline from 'readline';
+import { OutputChannel } from 'vscode';
+
+interface CompilationArtifact {
+    fileName: string;
+    name: string;
+    kind: string;
+    isTest: boolean;
+}
+
+export class Cargo {
+    rootFolder: string;
+    env?: Record<string, string>;
+    output: OutputChannel;
+
+    public constructor(cargoTomlFolder: string, output: OutputChannel, env: Record<string, string> | undefined = undefined) {
+        this.rootFolder = cargoTomlFolder;
+        this.output = output;
+        this.env = env;
+    }
+
+    public async artifactsFromArgs(cargoArgs: string[]): Promise<CompilationArtifact[]> {
+        const artifacts: CompilationArtifact[] = [];
+
+        try {
+            await this.runCargo(cargoArgs,
+                message => {
+                    if (message.reason === 'compiler-artifact' && message.executable) {
+                        const isBinary = message.target.crate_types.includes('bin');
+                        const isBuildScript = message.target.kind.includes('custom-build');
+                        if ((isBinary && !isBuildScript) || message.profile.test) {
+                            artifacts.push({
+                                fileName: message.executable,
+                                name: message.target.name,
+                                kind: message.target.kind[0],
+                                isTest: message.profile.test
+                            });
+                        }
+                    }
+                    else if (message.reason === 'compiler-message') {
+                        this.output.append(message.message.rendered);
+                    }
+                },
+                stderr => {
+                    this.output.append(stderr);
+                }
+            );
+        }
+        catch (err) {
+            this.output.show(true);
+            throw new Error(`Cargo invocation has failed: ${err}`);
+        }
+
+        return artifacts;
+    }
+
+    public async executableFromArgs(args: string[]): Promise<string> {
+        const cargoArgs = [...args]; // to remain  args unchanged
+        cargoArgs.push("--message-format=json");
+
+        const artifacts = await this.artifactsFromArgs(cargoArgs);
+
+        if (artifacts.length === 0) {
+            throw new Error('No compilation artifacts');
+        } else if (artifacts.length > 1) {
+            throw new Error('Multiple compilation artifacts are not supported.');
+        }
+
+        return artifacts[0].fileName;
+    }
+
+    runCargo(
+        cargoArgs: string[],
+        onStdoutJson: (obj: any) => void,
+        onStderrString: (data: string) => void
+    ): Promise<number> {
+        return new Promise<number>((resolve, reject) => {
+            const cargo = cp.spawn('cargo', cargoArgs, {
+                stdio: ['ignore', 'pipe', 'pipe'],
+                cwd: this.rootFolder,
+                env: this.env,
+            });
+
+            cargo.on('error', err => {
+                reject(new Error(`could not launch cargo: ${err}`));
+            });
+            cargo.stderr.on('data', chunk => {
+                onStderrString(chunk.toString());
+            });
+
+            const rl = readline.createInterface({ input: cargo.stdout });
+            rl.on('line', line => {
+                const message = JSON.parse(line);
+                onStdoutJson(message);
+            });
+
+            cargo.on('exit', (exitCode, _) => {
+                if (exitCode === 0)
+                    resolve(exitCode);
+                else
+                    reject(new Error(`exit code: ${exitCode}.`));
+            });
+        });
+    }
+}
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