fix(@ngtools/webpack): implement getModifiedResourceFiles for Ivy AOT

This method enables the Ivy incremental compiler to track changes to resource files and their requisites.

Author: clydin

packages/ngtools/webpack/src/compiler_host.ts

@@ -32,6 +32,7 @@ export class WebpackCompilerHost implements ts.CompilerHost {
   private _syncHost: virtualFs.SyncDelegateHost;
   private _memoryHost: virtualFs.SyncDelegateHost;
   private _changedFiles = new Set<string>();
+  private _readResourceFiles = new Set<string>();
   private _basePath: Path;
   private _resourceLoader?: WebpackResourceLoader;
   private _sourceFileCache = new Map<string, ts.SourceFile>();
@@ -341,6 +342,8 @@ export class WebpackCompilerHost implements ts.CompilerHost {
   }
 
   readResource(fileName: string) {
+    this._readResourceFiles.add(fileName);
+
     if (this.directTemplateLoading &&
         (fileName.endsWith('.html') || fileName.endsWith('.svg'))) {
       return this.readFile(fileName);
@@ -356,6 +359,25 @@ export class WebpackCompilerHost implements ts.CompilerHost {
     }
   }
 
+  getModifiedResourceFiles(): Set<string> {
+    const modifiedFiles = new Set<string>();
+
+    for (const changedFile of this._changedFiles) {
+      if (this._readResourceFiles.has(changedFile)) {
+        modifiedFiles.add(changedFile);
+      }
+
+      if (!this._resourceLoader) {
+        continue;
+      }
+      for (const resourcePath of this._resourceLoader.getAffectedResources(changedFile)) {
+          modifiedFiles.add(resourcePath);
+      }
+    }
+
+    return modifiedFiles;
+  }
+
   trace(message: string) {
     console.log(message);
   }

packages/ngtools/webpack/src/resource_loader.ts

@@ -27,6 +27,7 @@ export class WebpackResourceLoader {
   private _parentCompilation: any;
   private _context: string;
   private _fileDependencies = new Map<string, string[]>();
+  private _reverseDependencies = new Map<string, string[]>();
   private _cachedSources = new Map<string, string>();
   private _cachedEvaluatedSources = new Map<string, RawSource>();
 
@@ -41,6 +42,10 @@ export class WebpackResourceLoader {
     return this._fileDependencies.get(filePath) || [];
   }
 
+  getAffectedResources(file: string) {
+    return this._reverseDependencies.get(file) || [];
+  }
+
   private _compile(filePath: string): Promise<CompilationOutput> {
 
     if (!this._parentCompilation) {
@@ -117,6 +122,14 @@ export class WebpackResourceLoader {
 
           // Save the dependencies for this resource.
           this._fileDependencies.set(filePath, childCompilation.fileDependencies);
+          for (const file of childCompilation.fileDependencies) {
+            const entry = this._reverseDependencies.get(file);
+            if (entry) {
+              entry.push(filePath);
+            } else {
+              this._reverseDependencies.set(file, [filePath]);
+            }
+          }
 
           const compilationHash = childCompilation.fullHash;
           const maybeSource = this._cachedSources.get(compilationHash);