Switch CommandCacheKey back to an enum

The code reads better/simpler as an `enum`.

Author: mario-campos

lib/entry-points.js

@@ -8,6 +8,7 @@ import { setupTests } from "../testing-utils";
 
 import {
   cacheCommandOutput,
+  CommandCacheKey,
   getCachedCommandOutput,
   resetCachedCommandOutputs,
   type VersionInfo,
@@ -51,16 +52,13 @@ test.serial(
   async (t) => {
     await withCacheDir((cacheFilePath) => {
       writeCacheFile(cacheFilePath, {
-        version: {
+        [CommandCacheKey.Version]: {
           cmd: "/path/to/codeql",
           output: { version: "2.20.0" },
         },
       });
       t.deepEqual(
-        getCachedCommandOutput(
-          "version",
-          "/path/to/codeql",
-        ),
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
         { version: "2.20.0" },
       );
     });
@@ -72,16 +70,13 @@ test.serial(
   async (t) => {
     await withCacheDir((cacheFilePath) => {
       writeCacheFile(cacheFilePath, {
-        version: {
+        [CommandCacheKey.Version]: {
           cmd: "/path/to/other-codeql",
           output: { version: "2.20.0" },
         },
       });
       t.is(
-        getCachedCommandOutput(
-          "version",
-          "/path/to/codeql",
-        ),
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
         undefined,
       );
     });
@@ -94,10 +89,7 @@ test.serial(
     await withCacheDir((cacheFilePath) => {
       fs.writeFileSync(cacheFilePath, "not valid json");
       t.is(
-        getCachedCommandOutput(
-          "version",
-          "/path/to/codeql",
-        ),
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
         undefined,
       );
     });
@@ -109,10 +101,7 @@ test.serial(
   async (t) => {
     await withCacheDir(() => {
       t.is(
-        getCachedCommandOutput(
-          "version",
-          "/path/to/codeql",
-        ),
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
         undefined,
       );
     });
@@ -131,13 +120,10 @@ test.serial(
       ]) {
         resetCachedCommandOutputs();
         writeCacheFile(cacheFilePath, {
-          version: { cmd: "/path/to/codeql", output },
+          [CommandCacheKey.Version]: { cmd: "/path/to/codeql", output },
         });
         t.is(
-          getCachedCommandOutput(
-            "version",
-            "/path/to/codeql",
-          ),
+          getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
           undefined,
           JSON.stringify(output),
         );
@@ -151,13 +137,10 @@ test.serial(
   async (t) => {
     await withCacheDir((cacheFilePath) => {
       writeCacheFile(cacheFilePath, {
-        version: { output: { version: "2.20.0" } },
+        [CommandCacheKey.Version]: { output: { version: "2.20.0" } },
       });
       t.is(
-        getCachedCommandOutput(
-          "version",
-          "/path/to/codeql",
-        ),
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
         undefined,
       );
     });
@@ -167,10 +150,13 @@ test.serial(
 test.serial("cacheCommandOutput persists the output to the memo", async (t) => {
   await withCacheDir(() => {
     const output: VersionInfo = { version: "2.20.0" };
-    cacheCommandOutput("version", "/path/to/codeql", output);
+    cacheCommandOutput(CommandCacheKey.Version, "/path/to/codeql", output);
 
     // Tier 1: the value is immediately available from the memo.
-    t.deepEqual(getCachedCommandOutput("version", "/path/to/codeql"), output);
+    t.deepEqual(
+      getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+      output,
+    );
   });
 });
 
@@ -179,16 +165,19 @@ test.serial(
   async (t) => {
     await withCacheDir((cacheFilePath) => {
       const output: VersionInfo = { version: "2.20.0", overlayVersion: 1 };
-      cacheCommandOutput("version", "/path/to/codeql", output);
+      cacheCommandOutput(CommandCacheKey.Version, "/path/to/codeql", output);
 
       // Overwrite the file with a different value; the memo (tier 1) should win.
       writeCacheFile(cacheFilePath, {
-        version: {
+        [CommandCacheKey.Version]: {
           cmd: "/path/to/codeql",
           output: { version: "2.21.0" },
         },
       });
-      t.deepEqual(getCachedCommandOutput("version", "/path/to/codeql"), output);
+      t.deepEqual(
+        getCachedCommandOutput(CommandCacheKey.Version, "/path/to/codeql"),
+        output,
+      );
     });
   },
 );

src/cli/output-cache.test.ts

@@ -12,7 +12,10 @@ import { getActionsLogger } from "../logging";
 const COMMAND_CACHE_FILENAME = "codeql-action-command-cache.json";
 
 /** A key used to identify cached command output. */
-export type CommandCacheKey = "version" | "resolve languages";
+export enum CommandCacheKey {
+  Version = "version",
+  ResolveLanguages = "resolve languages",
+}
 
 export interface VersionInfo {
   version: string;
@@ -78,17 +81,17 @@ export function isResolveLanguagesOutput(
 }
 
 export type CommandCacheKeyOutputMap = {
-  version: VersionInfo;
-  "resolve languages": ResolveLanguagesOutput;
+  [CommandCacheKey.Version]: VersionInfo;
+  [CommandCacheKey.ResolveLanguages]: ResolveLanguagesOutput;
 };
 
 const commandCacheValidators: {
   [K in CommandCacheKey]: (
     output: unknown,
   ) => output is CommandCacheKeyOutputMap[K];
 } = {
-  version: isVersionInfo,
-  "resolve languages": isResolveLanguagesOutput,
+  [CommandCacheKey.Version]: isVersionInfo,
+  [CommandCacheKey.ResolveLanguages]: isResolveLanguagesOutput,
 };
 
 interface StoredCommandCacheEntry {
@@ -174,8 +177,8 @@ export function cacheCommandOutput<K extends CommandCacheKey>(
  *
  * Resolves tier 1 (in-memory memo) first, then tier 2 (temporary file). A value
  * loaded from the file is ignored unless its `cmd` matches the optional `cmd`
- * argument, and it satisfies the optional `validate` type guard; valid values
- * are memoized into tier 1 before being returned.
+ * argument and its output satisfies the internal validator for `key`; valid
+ * values are memoized into tier 1 before being returned.
  *
  * A return value of `undefined` signals the caller to fall back to tier 3 (the
  * CLI).

src/cli/output-cache.ts

@@ -14,9 +14,9 @@ import {
 import * as api from "./api-client";
 import {
   cacheCommandOutput,
+  CommandCacheKey,
   getCachedCommandOutput,
   type CommandCacheKeyOutputMap,
-  type CommandCacheKey,
   type ResolveLanguagesOutput,
   type VersionInfo,
 } from "./cli/output-cache";
@@ -515,7 +515,7 @@ async function getCodeQLForCmd(
       return cmd;
     },
     async getVersion() {
-      return getCachedOrRun("version", cmd, () =>
+      return getCachedOrRun(CommandCacheKey.Version, cmd, () =>
         runCliJson<VersionInfo>(cmd, ["version", "--format=json"], {
           noStreamStdout: true,
         }),
@@ -718,7 +718,7 @@ async function getCodeQLForCmd(
       await runCli(cmd, args);
     },
     async resolveLanguages() {
-      return getCachedOrRun("resolve languages", cmd, async () => {
+      return getCachedOrRun(CommandCacheKey.ResolveLanguages, cmd, async () => {
         const isFilterToLanguagesWithQueriesSupported =
           await this.supportsFeature(
             ToolsFeature.BuiltinExtractorsSpecifyDefaultQueries,