fix(@schematics/angular): update script should remove rxjs from the import blacklist

fixes angular/angular-cli#10259

Author: Brocco

packages/schematics/angular/migrations/update-6/index.ts

@@ -543,6 +543,28 @@ function updatePackageJson(packageManager?: string) {
   };
 }
 
+function updateTsLintConfig(): Rule {
+  return (host: Tree, context: SchematicContext) => {
+    const tsLintPath = '/tslint.json';
+    const buffer = host.read(tsLintPath);
+    if (!buffer) {
+      return;
+    }
+    const tsCfg = JSON.parse(buffer.toString());
+
+    if (tsCfg.rules && tsCfg.rules['import-blacklist'] &&
+        tsCfg.rules['import-blacklist'].indexOf('rxjs') !== -1) {
+
+      tsCfg.rules['import-blacklist'] = tsCfg.rules['import-blacklist']
+        .filter((rule: string | boolean) => rule !== 'rxjs');
+
+      host.overwrite(tsLintPath, JSON.stringify(tsCfg, null, 2));
+    }
+
+    return host;
+  };
+}
+
 export default function (): Rule {
   return (host: Tree, context: SchematicContext) => {
     const configPath = getConfigPath(host);
@@ -557,6 +579,7 @@ export default function (): Rule {
       migrateConfiguration(config),
       updateSpecTsConfig(config),
       updatePackageJson(config.packageManager),
+      updateTsLintConfig(),
     ])(host, context);
   };
 }

packages/schematics/angular/migrations/update-6/index_spec.ts

@@ -688,4 +688,36 @@ describe('Migration to v6', () => {
       expect(pkg.devDependencies['@angular-devkit/build-angular']).toBeDefined();
     });
   });
+
+  describe('tslint.json', () => {
+    const tslintPath = '/tslint.json';
+    // tslint:disable-next-line:no-any
+    let tslintConfig: any;
+    beforeEach(() => {
+      tslintConfig = {
+        rules: {
+          'import-blacklist': ['rxjs'],
+        },
+      };
+    });
+
+    it('should remove "rxjs" from the "import-blacklist" rule', () => {
+      tree.create(oldConfigPath, JSON.stringify(baseConfig, null, 2));
+      tree.create(tslintPath, JSON.stringify(tslintConfig, null, 2));
+      tree = schematicRunner.runSchematic('migration-01', defaultOptions, tree);
+      const tslint = JSON.parse(tree.readContent(tslintPath));
+      const blacklist = tslint.rules['import-blacklist'];
+      expect(blacklist).toEqual([]);
+    });
+
+    it('should work if "rxjs" is not in the "import-blacklist" rule', () => {
+      tree.create(oldConfigPath, JSON.stringify(baseConfig, null, 2));
+      tslintConfig.rules['import-blacklist'] = [];
+      tree.create(tslintPath, JSON.stringify(tslintConfig, null, 2));
+      tree = schematicRunner.runSchematic('migration-01', defaultOptions, tree);
+      const tslint = JSON.parse(tree.readContent(tslintPath));
+      const blacklist = tslint.rules['import-blacklist'];
+      expect(blacklist).toEqual([]);
+    });
+  });
 });