refactor(@ngtools/webpack): use Webpack 5 modified/removed file sets for changed list

Webpack 5 directly provides the set of modified and removed files. This feature allows for the removal of the file timestamp logic within the plugin that was previously used to generated the set of changed files on a rebuild.

(cherry picked from commit 86754e4)

Author: clydin

packages/ngtools/webpack/src/ivy/cache.ts

@@ -11,36 +11,12 @@ import { normalizePath } from './paths';
 export class SourceFileCache extends Map<string, ts.SourceFile> {
   private readonly angularDiagnostics = new Map<ts.SourceFile, ts.Diagnostic[]>();
 
-  invalidate(
-    fileTimestamps: Map<string, 'ignore' | number | { safeTime: number } | null>,
-    buildTimestamp: number,
-  ): Set<string> {
-    const changedFiles = new Set<string>();
-    for (const [file, timeOrEntry] of fileTimestamps) {
-      if (timeOrEntry === 'ignore') {
-        continue;
-      }
-
-      let time;
-      if (typeof timeOrEntry === 'number') {
-        time = timeOrEntry;
-      } else if (timeOrEntry) {
-        time = timeOrEntry.safeTime;
-      }
-
-      if (!time || time >= buildTimestamp) {
-        // Cache stores paths using the POSIX directory separator
-        const normalizedFile = normalizePath(file);
-        const sourceFile = this.get(normalizedFile);
-        if (sourceFile) {
-          this.delete(normalizedFile);
-          this.angularDiagnostics.delete(sourceFile);
-        }
-        changedFiles.add(normalizedFile);
-      }
+  invalidate(file: string): void {
+    const sourceFile = this.get(file);
+    if (sourceFile) {
+      this.delete(file);
+      this.angularDiagnostics.delete(sourceFile);
     }
-
-    return changedFiles;
   }
 
   updateAngularDiagnostics(sourceFile: ts.SourceFile, diagnostics: ts.Diagnostic[]): void {

packages/ngtools/webpack/src/ivy/plugin.ts

@@ -95,7 +95,6 @@ export class AngularWebpackPlugin {
   private ngtscNextProgram?: NgtscProgram;
   private builder?: ts.EmitAndSemanticDiagnosticsBuilderProgram;
   private sourceFileCache?: SourceFileCache;
-  private buildTimestamp!: number;
   private readonly fileDependencies = new Map<string, Set<string>>();
   private readonly requiredFilesToEmit = new Set<string>();
   private readonly requiredFilesToEmitCache = new Map<string, EmitFileResult | undefined>();
@@ -204,12 +203,15 @@ export class AngularWebpackPlugin {
       let cache = this.sourceFileCache;
       let changedFiles;
       if (cache) {
-        // Invalidate existing cache based on compiler file timestamps
-        changedFiles = cache.invalidate(compiler.fileTimestamps, this.buildTimestamp);
-
-        // Invalidate file dependencies of changed files
-        for (const changedFile of changedFiles) {
-          this.fileDependencies.delete(normalizePath(changedFile));
+        changedFiles = new Set<string>();
+        for (const changedFile of [...compiler.modifiedFiles, ...compiler.removedFiles]) {
+          const normalizedChangedFile = normalizePath(changedFile);
+          // Invalidate file dependencies
+          this.fileDependencies.delete(normalizedChangedFile);
+          // Invalidate existing cache
+          cache.invalidate(normalizedChangedFile);
+
+          changedFiles.add(normalizedChangedFile);
         }
       } else {
         // Initialize a new cache
@@ -219,7 +221,6 @@ export class AngularWebpackPlugin {
           this.sourceFileCache = cache;
         }
       }
-      this.buildTimestamp = Date.now();
       augmentHostWithCaching(host, cache);
 
       const moduleResolutionCache = ts.createModuleResolutionCache(