src/util.ts: throw error when getGoVersion fails

In most cases the use of getGoVersion is expected to return a value.
Updating the function to throw an error in the case that a Go
version is not found makes this explicit. For the exceptions where
an explicit binary path is requested we handle the error thrown and
show the existing warnings.

For #57.

Change-Id: Ib80ceec0636134b6694b0080ff19e0295d49d59f
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/400996
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Reviewed-by: Jamal Carvalho <jamal@golang.org>

src/goEnvironmentStatus.ts

@@ -172,12 +172,16 @@ export async function setSelectedGo(goOption: vscode.QuickPickItem, promptReload
 			vscode.window.showErrorMessage(`${newGoBin} is not an executable`);
 			return false;
 		}
-		const newGo = await getGoVersion(newGoBin);
-		if (!newGo || !newGo.isValid()) {
-			vscode.window.showErrorMessage(`failed to get "${newGoBin} version", invalid Go binary`);
-			return false;
+		let newGo: GoVersion | undefined;
+		try {
+			newGo = await getGoVersion(newGoBin);
+			await updateWorkspaceState('selectedGo', new GoEnvironmentOption(newGo.binaryPath, formatGoVersion(newGo)));
+		} catch (e) {
+			if (!newGo || !newGo.isValid()) {
+				vscode.window.showErrorMessage(`failed to get "${newGoBin} version", invalid Go binary:\n${e}`);
+				return false;
+			}
 		}
-		await updateWorkspaceState('selectedGo', new GoEnvironmentOption(newGo.binaryPath, formatGoVersion(newGo)));
 	}
 	// prompt the user to reload the window.
 	// promptReload defaults to true and should only be false for tests.

src/goInstallTools.ts

@@ -96,20 +96,24 @@ export async function installAllTools(updateExistingToolsOnly = false) {
 	);
 }
 
-export async function getGoForInstall(goVersion?: GoVersion, silent?: boolean): Promise<GoVersion> {
+export async function getGoForInstall(goVersion: GoVersion, silent?: boolean): Promise<GoVersion> {
 	const configured = getGoConfig().get<string>('toolsManagement.go');
 	if (!configured) {
 		return goVersion;
 	}
 	if (executableFileExists(configured)) {
-		const go = await getGoVersion(configured);
-		if (go) return go;
-	}
-	if (!silent) {
-		outputChannel.appendLine(
-			`Ignoring misconfigured 'go.toolsManagement.go' (${configured}). Provide a valid Go command.`
-		);
+		try {
+			const go = await getGoVersion(configured);
+			if (go) return go;
+		} finally {
+			if (!silent) {
+				outputChannel.appendLine(
+					`Ignoring misconfigured 'go.toolsManagement.go' (${configured}). Provide a valid Go command.`
+				);
+			}
+		}
 	}
+
 	return goVersion;
 }
 

src/util.ts

@@ -321,54 +321,53 @@ export function getUserNameHash() {
 
 /**
  * Gets version of Go based on the output of the command `go version`.
- * Returns undefined if go version can't be determined because
- * go is not available or `go version` fails.
+ * Throws if go version can't be determined because go is not available
+ * or `go version` fails.
  */
-export async function getGoVersion(goBinPath?: string): Promise<GoVersion | undefined> {
+export async function getGoVersion(goBinPath?: string): Promise<GoVersion> {
 	// TODO(hyangah): limit the number of concurrent getGoVersion call.
 	// When the extension starts, at least 4 concurrent calls race
 	// and end up calling `go version`.
 
 	const goRuntimePath = goBinPath ?? getBinPath('go');
 
-	const warn = (msg: string) => {
+	const error = (msg: string) => {
 		outputChannel.appendLine(msg);
 		console.warn(msg);
+		return new Error(msg);
 	};
 
 	if (!goRuntimePath) {
-		warn(`unable to locate "go" binary in GOROOT (${getCurrentGoRoot()}) or PATH (${envPath})`);
-		return;
+		throw error(`unable to locate "go" binary in GOROOT (${getCurrentGoRoot()}) or PATH (${envPath})`);
 	}
 	if (cachedGoBinPath === goRuntimePath && cachedGoVersion) {
 		if (cachedGoVersion.isValid()) {
 			return Promise.resolve(cachedGoVersion);
 		}
-		warn(`cached Go version (${JSON.stringify(cachedGoVersion)}) is invalid, recomputing`);
+		// Don't throw an the error. Continue and recompute go version.
+		error(`cached Go version (${JSON.stringify(cachedGoVersion)}) is invalid, recomputing`);
 	}
 	const docUri = vscode.window.activeTextEditor?.document.uri;
 	const cwd = getWorkspaceFolderPath(docUri && docUri.fsPath.endsWith('.go') ? docUri : undefined);
 
-	let goVersion: GoVersion;
+	let goVersion: GoVersion | undefined;
 	try {
 		const env = toolExecutionEnvironment();
 		const execFile = util.promisify(cp.execFile);
 		const { stdout, stderr } = await execFile(goRuntimePath, ['version'], { env, cwd });
 		if (stderr) {
-			warn(`failed to run "${goRuntimePath} version": stdout: ${stdout}, stderr: ${stderr}`);
-			return;
+			error(`failed to run "${goRuntimePath} version": stdout: ${stdout}, stderr: ${stderr}`);
 		}
 		goVersion = new GoVersion(goRuntimePath, stdout);
 	} catch (err) {
-		warn(`failed to run "${goRuntimePath} version": ${err} cwd: ${cwd}`);
-		return;
+		throw error(`failed to run "${goRuntimePath} version": ${err} cwd: ${cwd}`);
 	}
 	if (!goBinPath) {
 		// if getGoVersion was called with a given goBinPath, don't cache the result.
 		cachedGoBinPath = goRuntimePath;
 		cachedGoVersion = goVersion;
 		if (!cachedGoVersion.isValid()) {
-			warn(`unable to determine version from the output of "${goRuntimePath} version": "${goVersion.svString}"`);
+			error(`unable to determine version from the output of "${goRuntimePath} version": "${goVersion.svString}"`);
 		}
 	}
 	return goVersion;