fixup! fix(@angular/build): scope BundlerContext invalidation and cache one-shot bundle results

Author: alan-agius4

packages/angular/build/src/tools/esbuild/bundler-context.ts

@@ -81,7 +81,7 @@ export class BundlerContext {
   #optionsFactory: BundlerOptionsFactory<BuildOptions & { metafile: true; write: false }>;
   #shouldCacheResult: boolean;
   #loadCache?: LoadResultCache;
-  readonly #loadCacheKeys = new Set<string>();
+  #loadCacheKeys?: Set<string>;
   #invalidationEpoch = 0;
   readonly watchFiles = new Set<string>();
 
@@ -94,9 +94,8 @@ export class BundlerContext {
     sharedLoadCache?: LoadResultCache,
   ) {
     this.#loadCache = sharedLoadCache;
-    // In incremental mode, an option factory is needed to capture the full set of dependencies.
-    // In non-incremental mode, results can always be cached for the duration of the build.
-    this.#shouldCacheResult = !incremental || typeof options === 'function';
+    // To cache the results an option factory is needed to capture the full set of dependencies
+    this.#shouldCacheResult = incremental && typeof options === 'function';
     this.#optionsFactory = (...args) => {
       const baseOptions = typeof options === 'function' ? options(...args) : options;
 
@@ -230,22 +229,25 @@ export class BundlerContext {
         this.#loadCache = new MemoryLoadResultCache();
       }
       const loadCache = this.#loadCache;
-      const scopedLoadCache: LoadResultCache | undefined = loadCache && {
-        get: (path) => {
-          this.#loadCacheKeys.add(path);
-
-          return loadCache.get(path);
-        },
-        put: (path, result) => {
-          this.#loadCacheKeys.add(path);
-
-          return loadCache.put(path, result);
-        },
-        invalidate: (path) => loadCache.invalidate(path),
-        get watchFiles() {
-          return loadCache.watchFiles;
-        },
-      };
+      const scopedLoadCache: LoadResultCache | undefined =
+        this.incremental && loadCache
+          ? {
+              get: (path) => {
+                (this.#loadCacheKeys ??= new Set()).add(path);
+
+                return loadCache.get(path);
+              },
+              put: (path, result) => {
+                (this.#loadCacheKeys ??= new Set()).add(path);
+
+                return loadCache.put(path, result);
+              },
+              invalidate: (path) => loadCache.invalidate(path),
+              get watchFiles() {
+                return loadCache.watchFiles;
+              },
+            }
+          : loadCache;
       this.#esbuildOptions = this.#optionsFactory(scopedLoadCache);
     }
 
@@ -476,7 +478,7 @@ export class BundlerContext {
   }
 
   async #addLoadCacheFilesToWatch(): Promise<void> {
-    if (this.incremental && this.#loadCache) {
+    if (this.incremental && this.#loadCache && this.#loadCacheKeys) {
       for (const key of this.#loadCacheKeys) {
         const cachedResult = await this.#loadCache.get(key);
         if (cachedResult?.watchFiles) {
@@ -585,7 +587,7 @@ export class BundlerContext {
       this.#esbuildResult = undefined;
       this.#activeBundlePromise = undefined;
       this.#loadCache = undefined;
-      this.#loadCacheKeys.clear();
+      this.#loadCacheKeys = undefined;
       await this.#esbuildContext?.dispose();
     } finally {
       this.#esbuildContext = undefined;

packages/angular/build/src/tools/esbuild/bundler-context_spec.ts

@@ -222,43 +222,5 @@ describe('BundlerContext', () => {
         expect(recoveredResult.outputFiles[0].text).toContain('purple');
       }
     });
-
-    it('should reuse cached result when calling bundle() twice on a non-incremental context', async () => {
-      const workspaceDir = await mkdtemp(join(tempRoot, 'non-incremental-cache-'));
-      const stylePath = join(workspaceDir, 'shared.css');
-      await writeFile(stylePath, '.shared { color: orange; }');
-
-      let loadCount = 0;
-      const context = new BundlerContext(
-        workspaceDir,
-        /* incremental */ false,
-        () => ({
-          absWorkingDir: workspaceDir,
-          bundle: true,
-          entryPoints: [stylePath],
-          outdir: workspaceDir,
-          plugins: [
-            {
-              name: 'count-loads',
-              setup(build) {
-                build.onLoad({ filter: /\.css$/ }, async () => {
-                  loadCount++;
-
-                  return null;
-                });
-              },
-            },
-          ],
-        }),
-        /* useContext */ false,
-      );
-
-      const firstResult = await context.bundle();
-      const secondResult = await context.bundle();
-
-      expect(firstResult.errors).toBeUndefined();
-      expect(secondResult).toBe(firstResult);
-      expect(loadCount).toBe(1);
-    });
   });
 });