fix(cdk/schematics): update JSON.parse usages to cast the result as a type

Update JSON.parse usages to be better typed rather than resulting in an
any type.

Author: josephperrott

src/cdk/schematics/ng-add/index.spec.ts

@@ -4,6 +4,10 @@ import {COLLECTION_PATH} from '../index.spec';
 import {createTestApp, getFileContent} from '../testing';
 import {addPackageToPackageJson} from './package-config';
 
+interface PackageJson {
+  dependencies: {[key: string]: string};
+}
+
 describe('CDK ng-add', () => {
   let runner: SchematicTestRunner;
   let appTree: Tree;
@@ -15,7 +19,7 @@ describe('CDK ng-add', () => {
 
   it('should update the package.json', async () => {
     const tree = await runner.runSchematicAsync('ng-add', {}, appTree).toPromise();
-    const packageJson = JSON.parse(getFileContent(tree, '/package.json'));
+    const packageJson = JSON.parse(getFileContent(tree, '/package.json')) as PackageJson;
     const dependencies = packageJson.dependencies;
 
     expect(dependencies['@angular/cdk']).toBe('~0.0.0-PLACEHOLDER');
@@ -33,7 +37,7 @@ describe('CDK ng-add', () => {
     addPackageToPackageJson(appTree, '@angular/cdk', '^9.0.0');
 
     const tree = await runner.runSchematicAsync('ng-add', {}, appTree).toPromise();
-    const packageJson = JSON.parse(getFileContent(tree, '/package.json'));
+    const packageJson = JSON.parse(getFileContent(tree, '/package.json')) as PackageJson;
     const dependencies = packageJson.dependencies;
 
     expect(dependencies['@angular/cdk']).toBe('^9.0.0');

src/cdk/schematics/ng-add/package-config.ts

@@ -8,6 +8,10 @@
 
 import {Tree} from '@angular-devkit/schematics';
 
+interface PackageJson {
+  dependencies: {[key: string]: string};
+}
+
 /**
  * Sorts the keys of the given object.
  * @returns A new object instance with sorted keys
@@ -21,7 +25,7 @@ export function addPackageToPackageJson(host: Tree, pkg: string, version: string
 
   if (host.exists('package.json')) {
     const sourceText = host.read('package.json')!.toString('utf-8');
-    const json = JSON.parse(sourceText);
+    const json = JSON.parse(sourceText) as PackageJson;
 
     if (!json.dependencies) {
       json.dependencies = {};
@@ -44,7 +48,7 @@ export function getPackageVersionFromPackageJson(tree: Tree, name: string): stri
     return null;
   }
 
-  const packageJson = JSON.parse(tree.read('package.json')!.toString('utf8'));
+  const packageJson = JSON.parse(tree.read('package.json')!.toString('utf8')) as PackageJson;
 
   if (packageJson.dependencies && packageJson.dependencies[name]) {
     return packageJson.dependencies[name];