Cache CLI extractor paths across Actions steps

src/cli/output-cache.test.ts

@@ -0,0 +1,183 @@
+import * as fs from "fs";
+import * as os from "os";
+import path from "path";
+
+import test from "ava";
+
+import { setupTests } from "../testing-utils";
+
+import {
+  cacheCommandOutput,
+  CommandCacheKey,
+  getCachedCommandOutput,
+  resetCachedCommandOutputs,
+  type VersionInfo,
+} from "./output-cache";
+
+setupTests(test);
+
+const COMMAND_CACHE_FILENAME = "codeql-action-command-cache.json";
+
+/**
+ * Runs `body` with a temporary directory configured as the cache's backing
+ * store (`RUNNER_TEMP`). `CODEQL_ACTION_TEMP` is cleared so that
+ * `getTemporaryDirectory()` falls back to `RUNNER_TEMP`.
+ *
+ * `setupTests` snapshots and restores `process.env` around every test, so we
+ * don't restore the environment variables we set here ourselves.
+ */
+async function withCacheDir(
+  body: (cacheFilePath: string) => Promise<void> | void,
+): Promise<void> {
+  const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "cache-test-"));
+  process.env["RUNNER_TEMP"] = tmpDir;
+  delete process.env["CODEQL_ACTION_TEMP"];
+  resetCachedCommandOutputs();
+  try {
+    await body(path.join(tmpDir, COMMAND_CACHE_FILENAME));
+  } finally {
+    await fs.promises.rm(tmpDir, { force: true, recursive: true });
+  }
+}
+
+function writeCacheFile(
+  cacheFilePath: string,
+  contents: Record<string, unknown>,
+): void {
+  fs.writeFileSync(cacheFilePath, JSON.stringify(contents));
+}
+
+test.serial(
+  "getCachedCommandOutput reuses an output persisted by an earlier step",
+  async (t) => {
+    await withCacheDir((cacheFilePath) => {
+      writeCacheFile(cacheFilePath, {
+        [CommandCacheKey.Version]: {
+          cmd: "/path/to/codeql",
+          output: { version: "2.20.0" },
+        },
+      });
+      t.deepEqual(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        { version: "2.20.0" },
+      );
+    });
+  },
+);
+
+test.serial(
+  "getCachedCommandOutput ignores an output persisted from a different CLI",
+  async (t) => {
+    await withCacheDir((cacheFilePath) => {
+      writeCacheFile(cacheFilePath, {
+        [CommandCacheKey.Version]: {
+          cmd: "/path/to/other-codeql",
+          output: { version: "2.20.0" },
+        },
+      });
+      t.is(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        undefined,
+      );
+    });
+  },
+);
+
+test.serial(
+  "getCachedCommandOutput ignores a malformed cache file",
+  async (t) => {
+    await withCacheDir((cacheFilePath) => {
+      fs.writeFileSync(cacheFilePath, "not valid json");
+      t.is(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        undefined,
+      );
+    });
+  },
+);
+
+test.serial(
+  "getCachedCommandOutput returns undefined when there is no cache file",
+  async (t) => {
+    await withCacheDir(() => {
+      t.is(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        undefined,
+      );
+    });
+  },
+);
+
+test.serial(
+  "getCachedCommandOutput ignores an output that fails validation",
+  async (t) => {
+    await withCacheDir((cacheFilePath) => {
+      for (const output of [
+        {},
+        { version: 2 },
+        { version: "2.20.0", overlayVersion: "1" },
+        { version: "2.20.0", features: "nope" },
+      ]) {
+        resetCachedCommandOutputs();
+        writeCacheFile(cacheFilePath, {
+          [CommandCacheKey.Version]: { cmd: "/path/to/codeql", output },
+        });
+        t.is(
+          getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+          undefined,
+          JSON.stringify(output),
+        );
+      }
+    });
+  },
+);
+
+test.serial(
+  "getCachedCommandOutput ignores an entry missing the cmd field",
+  async (t) => {
+    await withCacheDir((cacheFilePath) => {
+      writeCacheFile(cacheFilePath, {
+        [CommandCacheKey.Version]: { output: { version: "2.20.0" } },
+      });
+      t.is(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        undefined,
+      );
+    });
+  },
+);
+
+test.serial("cacheCommandOutput persists the output to the memo", async (t) => {
+  await withCacheDir(() => {
+    const output: VersionInfo = { version: "2.20.0" };
+    cacheCommandOutput(CommandCacheKey.Version, "/path/to/codeql", output);
+
+    // Tier 1: the value is immediately available from the memo.
+    t.deepEqual(
+      getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+      output,
+    );
+  });
+});
+
+test.serial(
+  "getCachedCommandOutput prefers the in-memory memo over the file",
+  async (t) => {
+    await withCacheDir((cacheFilePath) => {
+      const output: VersionInfo = { version: "2.20.0", overlayVersion: 1 };
+      cacheCommandOutput(CommandCacheKey.Version, "/path/to/codeql", output);
+
+      // Overwrite the file with a different value; the memo (tier 1) should win.
+      writeCacheFile(cacheFilePath, {
+        [CommandCacheKey.Version]: {
+          cmd: "/path/to/codeql",
+          output: { version: "2.21.0" },
+        },
+      });
+      t.deepEqual(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        output,
+      );
+    });
+  },
+);