extension/src: rename latestToolVersion to latestModuleVersion

Refactor logic to determine the latest version to make it more
clear.

Replace type assersion using <> with as.
https://google.github.io/styleguide/tsguide.html#type-and-non-nullability-assertions

For #2891

Change-Id: I2977fcf6e8f77b7a2b7f2aa409f2206685cf59bf
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/693676
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Hongxiang Jiang <hxjiang@golang.org>
Commit-Queue: Hongxiang Jiang <hxjiang@golang.org>

Author: h9jiang

extension/src/goInstallTools.ts

@@ -343,7 +343,7 @@ async function installToolWithGo(
 
 	let version: semver.SemVer | string | undefined | null = tool.version;
 	if (!version && tool.usePrereleaseInPreviewMode && extensionInfo.isPreview) {
-		version = await latestToolVersion(tool, true);
+		version = await latestModuleVersion(tool.modulePath, true);
 	}
 	// TODO(hyangah): should we allow to choose a different version of the tool
 	// depending on the project's go version (i.e. getGoVersion())? For example,
@@ -733,17 +733,28 @@ async function suggestDownloadGo() {
 }
 
 /**
- * The output of `go list -m -versions -json`.
+ * Interface for the expected JSON output from `go list -m -versions -json`.
+ * See https://go.dev/ref/mod#go-list-m for details.
  */
 interface ListVersionsOutput {
-	Version: string; // module version
-	Versions?: string[]; // available module versions (with -versions)
+	/**
+	 * The latest tagged release version (e.g., v1.2.3). Excludes pre-releases.
+	 */
+	Version: string;
+	/**
+	 * All known versions of the module, sorted semantically from earliest to
+	 * latest. Includes pre-release versions.
+	 */
+	Versions?: string[];
 }
 
 /**
- * Returns the latest version of the tool.
+ * Returns the latest published versions of a Go module.
  */
-export async function latestToolVersion(tool: Tool, includePrerelease?: boolean): Promise<semver.SemVer | null> {
+export async function latestModuleVersion(
+	modulePath: string,
+	includePrerelease?: boolean
+): Promise<semver.SemVer | null> {
 	const goCmd = getBinPath('go');
 	const tmpDir = await tmpDirForToolInstallation();
 	const execFile = util.promisify(cp.execFile);
@@ -753,27 +764,28 @@ export async function latestToolVersion(tool: Tool, includePrerelease?: boolean)
 	try {
 		const env = toolInstallationEnvironment();
 		env['GO111MODULE'] = 'on';
-		// Run go list in a temp directory to avoid altering go.mod
-		// when using older versions of go (<1.16).
-		const version = 'latest'; // TODO(hyangah): use 'master' for delve-dap.
-		const { stdout } = await execFile(
-			goCmd,
-			['list', '-m', '--versions', '-json', `${tool.modulePath}@${version}`],
-			{
-				env,
-				cwd: tmpDir
-			}
-		);
-		const m = <ListVersionsOutput>JSON.parse(stdout);
-		// Versions field is a list of all known versions of the module,
-		// ordered according to semantic versioning, earliest to latest.
-		const latest = includePrerelease && m.Versions && m.Versions.length > 0 ? m.Versions.pop() : m.Version;
+		// Run go list in a temp directory to avoid altering go.mod when using
+		// older versions of go (<1.16).
+		const { stdout } = await execFile(goCmd, ['list', '-m', '--versions', '-json', `${modulePath}@latest`], {
+			env,
+			cwd: tmpDir
+		});
+		const moduleInfo = JSON.parse(stdout) as ListVersionsOutput;
+
+		let latest: string;
+		if (includePrerelease && moduleInfo.Versions && moduleInfo.Versions.length > 0) {
+			latest = moduleInfo.Versions[moduleInfo.Versions.length - 1];
+		} else {
+			latest = moduleInfo.Version;
+		}
+
 		ret = semver.parse(latest);
 	} catch (e) {
-		console.log(`failed to retrieve the latest tool ${tool.name} version: ${e}`);
+		console.log(`failed to retrieve the latest version of module ${modulePath}: ${e}`);
 	} finally {
 		rmdirRecursive(tmpDir);
 	}
+
 	return ret;
 }
 

extension/src/language/goLanguageServer.ts

@@ -40,7 +40,7 @@ import { Executable, LanguageClient, ServerOptions } from 'vscode-languageclient
 import { getGoConfig, getGoplsConfig, extensionInfo } from '../config';
 import { toolExecutionEnvironment } from '../goEnv';
 import { GoDocumentFormattingEditProvider, usingCustomFormatTool } from './legacy/goFormat';
-import { installTools, latestToolVersion, promptForMissingTool, promptForUpdatingTool } from '../goInstallTools';
+import { installTools, latestModuleVersion, promptForMissingTool, promptForUpdatingTool } from '../goInstallTools';
 import { getTool, Tool } from '../goTools';
 import { getFromGlobalState, updateGlobalState, updateWorkspaceState } from '../stateUtils';
 import {
@@ -1139,20 +1139,20 @@ export async function shouldUpdateLanguageServer(
 		return null;
 	}
 
-	// Get the latest gopls version. If it is for nightly, using the prereleased version is ok.
-	let latestVersion =
-		cfg.checkForUpdates === 'local' ? tool.latestVersion : await latestToolVersion(tool, extensionInfo.isPreview);
-
-	// If we failed to get the gopls version, pick the one we know to be latest at the time of this extension's last update
-	if (!latestVersion) {
-		latestVersion = tool.latestVersion;
+	let version = tool.latestVersion;
+	if (cfg.checkForUpdates === 'proxy') {
+		// Allow installation of gopls pre-releases on insider versions of the extension.
+		const latest = await latestModuleVersion(tool.modulePath, extensionInfo.isPreview);
+		if (latest) {
+			version = latest;
+		}
 	}
 
 	// If "gopls" is so old that it doesn't have the "gopls version" command,
 	// or its version doesn't match our expectations, usersVersion will be empty or invalid.
 	// Suggest the latestVersion.
 	if (!usersVersion || !semver.valid(usersVersion.version)) {
-		return latestVersion;
+		return version;
 	}
 
 	// The user may have downloaded golang.org/x/tools/gopls@master,
@@ -1161,12 +1161,12 @@ export async function shouldUpdateLanguageServer(
 	// If the user has a pseudoversion, get the timestamp for the latest gopls version and compare.
 	if (usersTime) {
 		let latestTime = cfg.checkForUpdates
-			? await getTimestampForVersion(tool, latestVersion!)
+			? await getTimestampForVersion(tool, version!)
 			: tool.latestVersionTimestamp;
 		if (!latestTime) {
 			latestTime = tool.latestVersionTimestamp;
 		}
-		return usersTime.isBefore(latestTime) ? latestVersion : null;
+		return usersTime.isBefore(latestTime) ? version : null;
 	}
 
 	// If the user's version does not contain a timestamp,
@@ -1175,7 +1175,7 @@ export async function shouldUpdateLanguageServer(
 		includePrerelease: true,
 		loose: true
 	});
-	return semver.lt(usersVersionSemver!, latestVersion!) ? latestVersion : null;
+	return semver.lt(usersVersionSemver!, version!) ? version : null;
 }
 
 // Copied from src/cmd/go/internal/modfetch.go.

extension/test/gopls/update.test.ts

@@ -98,7 +98,7 @@ suite('gopls update tests', () => {
 			sinon.replace(lsp, 'getLocalGoplsVersion', async () => {
 				return { version: usersVersion };
 			});
-			sinon.replace(goInstallTools, 'latestToolVersion', async () => {
+			sinon.replace(goInstallTools, 'latestModuleVersion', async () => {
 				if (acceptPrerelease) {
 					return latestPrereleaseVersion;
 				}