fix(@schematics/angular): add migration to ensure tslint deprecation rule

This ensures that projects will be warned when deprecated APIs are used when linted.

Author: clydin

packages/schematics/angular/migrations/migration-collection.json

@@ -94,6 +94,11 @@
       "version": "10.0.0-beta.6",
       "factory": "./update-10/update-angular-config",
       "description": "Remove various deprecated builders options from 'angular.json'."
+    },
+    "tslint-add-deprecation-rule": {
+      "version": "10.0.0-beta.7",
+      "factory": "./update-10/add-deprecation-rule-tslint",
+      "description": "Adds the tslint deprecation rule to tslint JSON configuration files."
     }
   }
 }

packages/schematics/angular/migrations/update-10/add-deprecation-rule-tslint.ts

@@ -0,0 +1,64 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * 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 { JsonAstObject, JsonValue } from '@angular-devkit/core';
+import { Rule } from '@angular-devkit/schematics';
+import { getPackageJsonDependency } from '../../utility/dependencies';
+import { findPropertyInAstObject, insertPropertyInAstObjectInOrder, removePropertyInAstObject } from '../../utility/json-utils';
+import { readJsonFileAsAstObject } from '../update-9/utils';
+
+const TSLINT_CONFIG_PATH = '/tslint.json';
+const RULES_TO_ADD: Record<string, JsonValue> = {
+  deprecation: {
+    severity: 'warning',
+  },
+};
+
+export default function (): Rule {
+  return (tree, context) => {
+    const logger = context.logger;
+
+    // Update tslint dependency
+    const current = getPackageJsonDependency(tree, 'tslint');
+
+    if (!current) {
+      logger.info('Skipping: "tslint" in not a dependency of this workspace.');
+
+      return;
+    }
+
+    // Update tslint config.
+    const tslintJsonAst = readJsonFileAsAstObject(tree, TSLINT_CONFIG_PATH);
+    if (!tslintJsonAst) {
+      const config = ['tslint.js', 'tslint.yaml'].find(c => tree.exists(c));
+      if (config) {
+        logger.warn(`Skipping: Expected a JSON configuration file but found "${config}".`);
+      } else {
+        logger.warn('Skipping: Cannot find "tslint.json" configuration file.');
+      }
+
+      return;
+    }
+
+    for (const [name, value] of Object.entries(RULES_TO_ADD)) {
+      const tslintJsonAst = readJsonFileAsAstObject(tree, TSLINT_CONFIG_PATH) as JsonAstObject;
+      const rulesAst = findPropertyInAstObject(tslintJsonAst, 'rules');
+      if (rulesAst?.kind !== 'object') {
+        break;
+      }
+
+      if (findPropertyInAstObject(rulesAst, name)) {
+        // Skip as rule already exists.
+        continue;
+      }
+
+      const recorder = tree.beginUpdate(TSLINT_CONFIG_PATH);
+      insertPropertyInAstObjectInOrder(recorder, rulesAst, name, value, 4);
+      tree.commitUpdate(recorder);
+    }
+  };
+}

packages/schematics/angular/migrations/update-10/add-deprecation-rule-tslint_spec.ts

@@ -0,0 +1,83 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * 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 { EmptyTree } from '@angular-devkit/schematics';
+import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';
+
+describe('Migration of tslint to version 6', () => {
+  const schematicRunner = new SchematicTestRunner(
+    'migrations',
+    require.resolve('../migration-collection.json'),
+  );
+
+  let tree: UnitTestTree;
+  const TSLINT_PATH = '/tslint.json';
+  const PACKAGE_JSON_PATH = '/package.json';
+
+  const PACKAGE_JSON = {
+    devDependencies: {
+      tslint: '~6.1.0',
+    },
+  };
+
+  beforeEach(() => {
+    tree = new UnitTestTree(new EmptyTree());
+    tree.create(PACKAGE_JSON_PATH, JSON.stringify(PACKAGE_JSON, null, 2));
+  });
+
+  it('should add new rules', async () => {
+    const config = {
+      extends: 'tslint:recommended',
+      rules: {
+        'no-use-before-declare': true,
+        'arrow-return-shorthand': false,
+        'label-position': true,
+      },
+    };
+    tree.create(TSLINT_PATH, JSON.stringify(config, null, 2));
+
+    const newTree = await schematicRunner.runSchematicAsync('tslint-add-deprecation-rule', {}, tree).toPromise();
+    const { rules } = JSON.parse(newTree.readContent(TSLINT_PATH));
+    expect(rules['deprecation'].severity).toBe('warning');
+  });
+
+  it('should not update already present rules', async () => {
+    const config = {
+      extends: 'tslint:recommended',
+      rules: {
+        'no-use-before-declare': true,
+        'arrow-return-shorthand': false,
+        'label-position': true,
+        deprecation: false,
+      },
+    };
+    tree.create(TSLINT_PATH, JSON.stringify(config, null, 2));
+
+    const newTree = await schematicRunner.runSchematicAsync('tslint-add-deprecation-rule', {}, tree).toPromise();
+    const { rules } = JSON.parse(newTree.readContent(TSLINT_PATH));
+    expect(rules['deprecation']).toBe(false);
+  });
+
+  it('should not update already present rules with different severity', async () => {
+    const config = {
+      extends: 'tslint:recommended',
+      rules: {
+        'no-use-before-declare': true,
+        'arrow-return-shorthand': false,
+        'label-position': true,
+        deprecation: {
+          severity: 'error',
+        },
+      },
+    };
+    tree.create(TSLINT_PATH, JSON.stringify(config, null, 2));
+
+    const newTree = await schematicRunner.runSchematicAsync('tslint-add-deprecation-rule', {}, tree).toPromise();
+    const { rules } = JSON.parse(newTree.readContent(TSLINT_PATH));
+    expect(rules['deprecation'].severity).toBe('error');
+  });
+});