refactor(ngcc): expose a hash of the project configuration (#35931)

This will be used in the entry-point manifest since a change to
configuration might change the entry-points that are found.

PR Close #35931

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

@@ -5,6 +5,7 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
+import {createHash} from 'crypto';
 import {satisfies} from 'semver';
 import * as vm from 'vm';
 import {AbsoluteFsPath, FileSystem, dirname, join, resolve} from '../../../src/ngtsc/file_system';
@@ -159,10 +160,12 @@ export class NgccConfiguration {
   private defaultConfig: NgccProjectConfig<VersionedPackageConfig[]>;
   private projectConfig: NgccProjectConfig<VersionedPackageConfig[]>;
   private cache = new Map<string, VersionedPackageConfig>();
+  readonly hash: string;
 
   constructor(private fs: FileSystem, baseDir: AbsoluteFsPath) {
     this.defaultConfig = this.processProjectConfig(baseDir, DEFAULT_NGCC_CONFIG);
     this.projectConfig = this.processProjectConfig(baseDir, this.loadProjectConfig(baseDir));
+    this.hash = this.computeHash();
   }
 
   /**
@@ -283,6 +286,10 @@ export class NgccConfiguration {
         ] :
         [packagePathAndVersion, undefined];
   }
+
+  private computeHash(): string {
+    return createHash('md5').update(JSON.stringify(this.projectConfig)).digest('hex');
+  }
 }
 
 function findSatisfactoryVersion(

packages/compiler-cli/ngcc/test/packages/configuration_spec.ts

@@ -5,6 +5,8 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
+import {createHash} from 'crypto';
+
 import {FileSystem, absoluteFrom, getFileSystem} from '../../../src/ngtsc/file_system';
 import {runInEachFileSystem} from '../../../src/ngtsc/file_system/testing';
 import {loadTestFiles} from '../../../test/helpers';
@@ -30,6 +32,58 @@ runInEachFileSystem(() => {
       });
     });
 
+    describe('hash', () => {
+      it('should compute a hash from the loaded and processed project configuration', () => {
+        const project1 = _Abs('/project-1');
+        const project1Config = fs.resolve(project1, 'ngcc.config.js');
+        const project1NodeModules = fs.resolve(project1, 'node_modules');
+        const project1Package1 = fs.resolve(project1NodeModules, 'package-1');
+        const project1Package1EntryPoint1 = fs.resolve(project1Package1, 'entry-point-1');
+
+        loadTestFiles([{
+          name: project1Config,
+          contents: `
+            module.exports = {
+              packages: {
+                'package-1': {entryPoints: {'./entry-point-1': {}}},
+              },
+            };`
+        }]);
+        const project1Conf = new NgccConfiguration(fs, project1);
+        const expectedProject1Config =
+            `{"packages":{"${project1Package1}":[{"entryPoints":{"${project1Package1EntryPoint1}":{}},"versionRange":"*"}]}}`;
+        expect(project1Conf.hash)
+            .toEqual(createHash('md5').update(expectedProject1Config).digest('hex'));
+
+        const project2 = _Abs('/project-2');
+        const project2Config = fs.resolve(project2, 'ngcc.config.js');
+        const project2NodeModules = fs.resolve(project2, 'node_modules');
+        const project2Package1 = fs.resolve(project2NodeModules, 'package-1');
+        const project2Package1EntryPoint1 = fs.resolve(project2Package1, 'entry-point-1');
+
+        loadTestFiles([{
+          name: project2Config,
+          contents: `
+              module.exports = {
+                packages: {
+                  'package-1': {entryPoints: {'./entry-point-1': {ignore: true}}},
+                },
+              };`
+        }]);
+        const project2Conf = new NgccConfiguration(fs, project2);
+        const expectedProject2Config =
+            `{"packages":{"${project2Package1}":[{"entryPoints":{"${project2Package1EntryPoint1}":{"ignore":true}},"versionRange":"*"}]}}`;
+        expect(project2Conf.hash)
+            .toEqual(createHash('md5').update(expectedProject2Config).digest('hex'));
+      });
+
+      it('should compute a hash even if there is no project configuration', () => {
+        loadTestFiles([{name: _Abs('/project-1/empty.js'), contents: ``}]);
+        const configuration = new NgccConfiguration(fs, _Abs('/project-1'));
+        expect(configuration.hash).toEqual('87c535c3ce0eac2a54c246892e0e21a1');
+      });
+    });
+
     describe('getConfig()', () => {
       describe('at the package level', () => {
         it('should return configuration for a package found in a package level file, with a matching version',