Read VS Code Electron version from .npmrc

extensions/ql-vscode/scripts/util/fetch.ts

@@ -1,10 +1,20 @@
-export async function fetchJson<T>(url: string): Promise<T> {
+async function fetchResponse(url: string): Promise<Response> {
   const response = await fetch(url);
   if (!response.ok) {
     throw new Error(
       `Could not fetch ${url}: ${response.status} ${response.statusText}`,
     );
   }
 
+  return response;
+}
+
+export async function fetchJson<T>(url: string): Promise<T> {
+  const response = await fetchResponse(url);
   return (await response.json()) as T;
 }
+
+export async function fetchText(url: string): Promise<string> {
+  const response = await fetchResponse(url);
+  return await response.text();
+}

extensions/ql-vscode/scripts/util/vscode-versions.ts

@@ -1,9 +1,9 @@
-import { minVersion } from "semver";
-import { fetchJson } from "./fetch";
+import { minVersion, valid } from "semver";
+import { fetchJson, fetchText } from "./fetch";
 
 type VsCodePackageJson = {
-  devDependencies: {
-    electron: string;
+  devDependencies?: {
+    electron?: string;
   };
 };
 
@@ -15,6 +15,40 @@
   );
 }
 
+async function getVsCodeNpmrc(version: string): Promise<string> {
+  return await fetchText(
+    `https://raw.githubusercontent.com/microsoft/vscode/${version}/.npmrc`,
+  );
+}
+
+export function parseElectronVersion(npmrc: string): string {
+  const electronVersion = /^target="([^"]+)"$/m.exec(npmrc)?.[1];
+  if (!electronVersion || !valid(electronVersion)) {
+    throw new Error(
+      "Could not find a valid Electron version in VS Code .npmrc",
+    );
+  }
+
+  return electronVersion;
+}
+
+async function getVsCodeElectronVersion(version: string): Promise<string> {
+  const packageJson = await getVsCodePackageJson(version);
+  const packageElectronVersion = packageJson.devDependencies?.electron;
+  if (packageElectronVersion) {
+    const electronVersion = minVersion(packageElectronVersion)?.version;
+    if (!electronVersion) {
+      throw new Error(
+        "Could not find a valid Electron version in VS Code package.json",
+      );
+    }
+
+    return electronVersion;
+  }
+
+  return parseElectronVersion(await getVsCodeNpmrc(version));
+}
+
 interface ElectronVersion {
   version: string;
   date: string;
@@ -44,13 +78,7 @@
 export async function getVersionInformation(
   vscodeVersion: string,
 ): Promise<VersionInformation> {
-  const vsCodePackageJson = await getVsCodePackageJson(vscodeVersion);
-  const electronVersion = minVersion(
-    vsCodePackageJson.devDependencies.electron,
-  )?.version;
-  if (!electronVersion) {
-    throw new Error("Could not find Electron version");
-  }
+  const electronVersion = await getVsCodeElectronVersion(vscodeVersion);
 
   const electronReleases = await getElectronReleases();
 

extensions/ql-vscode/test/unit-tests/scripts/util/vscode-versions.test.ts

@@ -0,0 +1,104 @@
+import {
+  getVersionInformation,
+  parseElectronVersion,
+} from "../../../../scripts/util/vscode-versions";
+
+const electronReleases = [
+  {
+    version: "29.4.0",
+    node: "20.9.0",
+    chrome: "122.0.6261.156",
+  },
+  {
+    version: "42.10.0",
+    node: "24.18.1",
+    chrome: "148.0.7778.280",
+  },
+];
+
+function mockFetch(
+  responses: Record<string, unknown>,
+): jest.SpiedFunction<typeof fetch> {
+  return jest.spyOn(globalThis, "fetch").mockImplementation(async (input) => {
+    const url = input.toString();
+    const response = responses[url];
+    if (response === undefined) {
+      throw new Error(`Unexpected URL: ${url}`);
+    }
+
+    return {
+      ok: true,
+      json: async () => response,
+      text: async () => response,
+    } as Response;
+  });
+}
+
+afterEach(() => {
+  jest.restoreAllMocks();
+});
+
+describe("parseElectronVersion", () => {
+  it("parses the Electron target from a VS Code .npmrc", () => {
+    expect(
+      parseElectronVersion(
+        ['target="42.10.0"', 'runtime="electron"', "disturl=example"].join(
+          "\n",
+        ),
+      ),
+    ).toBe("42.10.0");
+  });
+
+  it.each([
+    ["a missing target", 'runtime="electron"'],
+    ["an invalid target", 'target="not-a-version"'],
+    ["an unquoted target", "target=42.10.0"],
+  ])("rejects %s", (_description, npmrc) => {
+    expect(() => parseElectronVersion(npmrc)).toThrow(
+      "Could not find a valid Electron version in VS Code .npmrc",
+    );
+  });
+});
+
+describe("getVersionInformation", () => {
+  it("reads Electron from package.json for older VS Code releases", async () => {
+    const fetchMock = mockFetch({
+      "https://raw.githubusercontent.com/microsoft/vscode/1.90.0/package.json":
+        {
+          devDependencies: {
+            electron: "29.4.0",
+          },
+        },
+      "https://releases.electronjs.org/releases.json": electronReleases,
+    });
+
+    await expect(getVersionInformation("1.90.0")).resolves.toEqual({
+      vscodeVersion: "1.90.0",
+      electronVersion: "29.4.0",
+      nodeVersion: "20.9.0",
+      chromiumVersion: "122.0.6261.156",
+    });
+    expect(fetchMock).not.toHaveBeenCalledWith(
+      "https://raw.githubusercontent.com/microsoft/vscode/1.90.0/.npmrc",
+    );
+  });
+
+  it("falls back to .npmrc for newer VS Code releases", async () => {
+    mockFetch({
+      "https://raw.githubusercontent.com/microsoft/vscode/1.137.0/package.json":
+        {
+          devDependencies: {},
+        },
+      "https://raw.githubusercontent.com/microsoft/vscode/1.137.0/.npmrc":
+        'target="42.10.0"\nruntime="electron"\n',
+      "https://releases.electronjs.org/releases.json": electronReleases,
+    });
+
+    await expect(getVersionInformation("1.137.0")).resolves.toEqual({
+      vscodeVersion: "1.137.0",
+      electronVersion: "42.10.0",
+      nodeVersion: "24.18.1",
+      chromiumVersion: "148.0.7778.280",
+    });
+  });
+});