feat(ngcc): support invalidating the entry-point manifest (#35931)

In some scenarios it is useful for the developer to indicate
to ngcc that it should not use the entry-point manifest
file, and instead write a new one.

In the ngcc command line tool, this option is set by specfying

```
--invalidate-entry-point-manifest
```

PR Close #35931

packages/compiler-cli/ngcc/src/main.ts

@@ -39,7 +39,7 @@ import {hasBeenProcessed} from './packages/build_marker';
 import {NgccConfiguration} from './packages/configuration';
 import {EntryPoint, EntryPointJsonProperty, EntryPointPackageJson, SUPPORTED_FORMAT_PROPERTIES, getEntryPointFormat} from './packages/entry_point';
 import {makeEntryPointBundle} from './packages/entry_point_bundle';
-import {EntryPointManifest} from './packages/entry_point_manifest';
+import {EntryPointManifest, InvalidatingEntryPointManifest} from './packages/entry_point_manifest';
 import {Transformer} from './packages/transformer';
 import {PathMappings} from './utils';
 import {cleanOutdatedPackages} from './writing/cleaning/package_cleaner';
@@ -117,6 +117,15 @@ export interface SyncNgccOptions {
    * legacy message ids will all be stripped during translation.
    */
   enableI18nLegacyMessageIdFormat?: boolean;
+
+  /**
+   * Whether to invalidate any entry-point manifest file that is on disk. Instead, walk the
+   * directory tree looking for entry-points, and then write a new entry-point manifest, if
+   * possible.
+   *
+   * Default: `false` (i.e. the manifest will be used if available)
+   */
+  invalidateEntryPointManifest?: boolean;
 }
 
 /**
@@ -139,11 +148,12 @@ export type NgccOptions = AsyncNgccOptions | SyncNgccOptions;
  */
 export function mainNgcc(options: AsyncNgccOptions): Promise<void>;
 export function mainNgcc(options: SyncNgccOptions): void;
-export function mainNgcc(
-    {basePath, targetEntryPointPath, propertiesToConsider = SUPPORTED_FORMAT_PROPERTIES,
-     compileAllFormats = true, createNewEntryPointFormats = false,
-     logger = new ConsoleLogger(LogLevel.info), pathMappings, async = false,
-     enableI18nLegacyMessageIdFormat = true}: NgccOptions): void|Promise<void> {
+export function mainNgcc({basePath, targetEntryPointPath,
+                          propertiesToConsider = SUPPORTED_FORMAT_PROPERTIES,
+                          compileAllFormats = true, createNewEntryPointFormats = false,
+                          logger = new ConsoleLogger(LogLevel.info), pathMappings, async = false,
+                          enableI18nLegacyMessageIdFormat = true,
+                          invalidateEntryPointManifest = false}: NgccOptions): void|Promise<void> {
   // Execute in parallel, if async execution is acceptable and there are more than 1 CPU cores.
   const inParallel = async && (os.cpus().length > 1);
 
@@ -154,7 +164,9 @@ export function mainNgcc(
   const absBasePath = absoluteFrom(basePath);
   const config = new NgccConfiguration(fileSystem, dirname(absBasePath));
   const dependencyResolver = getDependencyResolver(fileSystem, logger, config, pathMappings);
-  const entryPointManifest = new EntryPointManifest(fileSystem, config, logger);
+  const entryPointManifest = invalidateEntryPointManifest ?
+      new InvalidatingEntryPointManifest(fileSystem, config, logger) :
+      new EntryPointManifest(fileSystem, config, logger);
 
   // Bail out early if the work is already done.
   const supportedPropertiesToConsider = ensureSupportedProperties(propertiesToConsider);

packages/compiler-cli/ngcc/src/packages/entry_point_manifest.ts

@@ -129,6 +129,18 @@ export class EntryPointManifest {
   }
 }
 
+/**
+ * A specialized implementation of the `EntryPointManifest` that can be used to invalidate the
+ * current manifest file.
+ *
+ * It always returns `null` from the `readEntryPointsUsingManifest()` method, which forces a new
+ * manifest to be created, which will overwrite the current file when `writeEntryPointManifest()` is
+ * called.
+ */
+export class InvalidatingEntryPointManifest extends EntryPointManifest {
+  readEntryPointsUsingManifest(basePath: AbsoluteFsPath): EntryPoint[]|null { return null; }
+}
+
 /**
  * The JSON format of the manifest file that is written to disk.
  */