Allowing a cached version of the CodeQL bundle sometimes

To save time downloading the CodeQL bundle we're pre-downloading it into the
hosted Actions runner, but because the release schedule is different there may
be some version drift. This change allows a different version of the bundle
to be used than the default if a version isn't explicitly specified, there's
only one version downloaded, and it's been marked as a 'pinned-version' -
otherwise it reverts to the prior behavior.

src/codeql.test.ts

@@ -7,6 +7,7 @@ import * as codeql from "./codeql";
 import { getRunnerLogger } from "./logging";
 import { setupTests } from "./testing-utils";
 import * as util from "./util";
+import * as defaults from "./defaults.json";
 
 setupTests(test);
 
@@ -43,6 +44,177 @@ test("download codeql bundle cache", async (t) => {
   });
 });
 
+test("download codeql bundle cache explicitly requested with pinned different version cached", async (t) => {
+  await util.withTmpDir(async (tmpDir) => {
+    nock("https://example.com")
+      .get(`/download/codeql-bundle-20200601/codeql-bundle.tar.gz`)
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle-pinned.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      "https://example.com/download/codeql-bundle-20200601/codeql-bundle.tar.gz",
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    t.assert(toolcache.find("CodeQL", "0.0.0-20200601"));
+
+    nock("https://example.com")
+      .get(`/download/codeql-bundle-20200610/codeql-bundle.tar.gz`)
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      "https://example.com/download/codeql-bundle-20200610/codeql-bundle.tar.gz",
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    t.assert(toolcache.find("CodeQL", "0.0.0-20200610"));
+  });
+});
+
+test("don't download codeql bundle cache with pinned different version cached", async (t) => {
+  await util.withTmpDir(async (tmpDir) => {
+    nock("https://example.com")
+      .get(`/download/codeql-bundle-20200601/codeql-bundle.tar.gz`)
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle-pinned.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      "https://example.com/download/codeql-bundle-20200601/codeql-bundle.tar.gz",
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    t.assert(toolcache.find("CodeQL", "0.0.0-20200601"));
+
+    await codeql.setupCodeQL(
+      undefined,
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    const cachedVersions = toolcache.findAllVersions("CodeQL");
+
+    t.is(cachedVersions.length, 1);
+  });
+});
+
+test("download codeql bundle cache with different version cached (not pinned)", async (t) => {
+  await util.withTmpDir(async (tmpDir) => {
+    nock("https://example.com")
+      .get(`/download/codeql-bundle-20200601/codeql-bundle.tar.gz`)
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      "https://example.com/download/codeql-bundle-20200601/codeql-bundle.tar.gz",
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    t.assert(toolcache.find("CodeQL", "0.0.0-20200601"));
+
+    nock("https://github.com")
+      .get(
+        `/github/codeql-action/releases/download/${defaults.bundleVersion}/codeql-bundle.tar.gz`
+      )
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      undefined,
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    const cachedVersions = toolcache.findAllVersions("CodeQL");
+
+    t.is(cachedVersions.length, 2);
+  });
+});
+
+test('download codeql bundle cache with pinned different version cached if "latests" tools specied', async (t) => {
+  await util.withTmpDir(async (tmpDir) => {
+    nock("https://example.com")
+      .get(`/download/codeql-bundle-20200601/codeql-bundle.tar.gz`)
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle-pinned.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      "https://example.com/download/codeql-bundle-20200601/codeql-bundle.tar.gz",
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    t.assert(toolcache.find("CodeQL", "0.0.0-20200601"));
+
+    nock("https://github.com")
+      .get(
+        `/github/codeql-action/releases/download/${defaults.bundleVersion}/codeql-bundle.tar.gz`
+      )
+      .replyWithFile(
+        200,
+        path.join(__dirname, `/../src/testdata/codeql-bundle.tar.gz`)
+      );
+
+    await codeql.setupCodeQL(
+      "latest",
+      "token",
+      "https://github.com",
+      tmpDir,
+      tmpDir,
+      "runner",
+      getRunnerLogger(true)
+    );
+
+    const cachedVersions = toolcache.findAllVersions("CodeQL");
+
+    t.is(cachedVersions.length, 2);
+  });
+});
+
 test("parse codeql bundle url version", (t) => {
   const tests = {
     "20200601": "0.0.0-20200601",

src/codeql.ts

@@ -235,12 +235,37 @@ export async function setupCodeQL(
   process.env["RUNNER_TOOL_CACHE"] = toolsDir;
 
   try {
+    // We use the special value of 'latest' to prioritize the version in the
+    // defaults over any pinned cached version.
+    const forceLatest = codeqlURL === "latest";
+    if (forceLatest) {
+      codeqlURL = undefined;
+    }
+
     const codeqlURLVersion = getCodeQLURLVersion(
       codeqlURL || `/${CODEQL_BUNDLE_VERSION}/`,
       logger
     );
 
+    // If we find the specified version, we always use that.
     let codeqlFolder = toolcache.find("CodeQL", codeqlURLVersion);
+
+    // If we don't find the requested version, in some cases we may allow a
+    // different version to save download time if the version hasn't been
+    // specified explicitly (in which case we always honor it).
+    if (!codeqlFolder && !codeqlURL && !forceLatest) {
+      const codeqlVersions = toolcache.findAllVersions("CodeQL");
+      if (codeqlVersions.length === 1) {
+        const tmpCodeqlFolder = toolcache.find("CodeQL", codeqlVersions[0]);
+        if (fs.existsSync(path.join(tmpCodeqlFolder, "pinned-version"))) {
+          logger.debug(
+            `CodeQL in cache overriding the default ${CODEQL_BUNDLE_VERSION}`
+          );
+          codeqlFolder = tmpCodeqlFolder;
+        }
+      }
+    }
+
     if (codeqlFolder) {
       logger.debug(`CodeQL found in cache ${codeqlFolder}`);
     } else {