fix(config): set allowJs: true internally always (#976)

Closes #974

examples/example-app-v10/tsconfig-esm.spec.json

@@ -1,7 +1,6 @@
 {
   "extends": "./tsconfig.spec.json",
   "compilerOptions": {
-    "module": "ESNext",
-    "allowJs": true
+    "module": "ESNext"
   }
 }

examples/example-app-v11/tsconfig-esm.spec.json

@@ -1,7 +1,6 @@
 {
   "extends": "./tsconfig.spec.json",
   "compilerOptions": {
-    "module": "ESNext",
-    "allowJs": true
+    "module": "ESNext"
   }
 }

examples/example-app-v12-monorepo/projects/app1/tsconfig-esm.spec.json

@@ -1,7 +1,6 @@
 {
   "extends": "./tsconfig.spec.json",
   "compilerOptions": {
-    "module": "ESNext",
-    "allowJs": true
+    "module": "ESNext"
   }
 }

examples/example-app-v12-monorepo/projects/app2/tsconfig-esm.spec.json

@@ -1,7 +1,6 @@
 {
   "extends": "./tsconfig.spec.json",
   "compilerOptions": {
-    "module": "ESNext",
-    "allowJs": true
+    "module": "ESNext"
   }
 }

examples/example-app-v12/tsconfig-esm.spec.json

@@ -1,7 +1,6 @@
 {
   "extends": "./tsconfig.spec.json",
   "compilerOptions": {
-    "module": "ESNext",
-    "allowJs": true
+    "module": "ESNext"
   }
 }

examples/example-app-v9/tsconfig-esm.spec.json

@@ -1,7 +1,6 @@
 {
   "extends": "./tsconfig.spec.json",
   "compilerOptions": {
-    "module": "ESNext",
-    "allowJs": true
+    "module": "ESNext"
   }
 }

src/__tests__/ng-jest-config.spec.ts

@@ -0,0 +1,15 @@
+import { NgJestConfig } from '../config/ng-jest-config';
+
+describe('NgJestConfig', () => {
+  test('should override some compiler options', () => {
+    const compilerOptions = new NgJestConfig(Object.create(null)).parsedTsConfig.options;
+
+    expect(compilerOptions.enableIvy).toBe(true);
+    expect(compilerOptions.noEmitOnError).toBe(false);
+    expect(compilerOptions.suppressOutputPathCheck).toBe(true);
+    expect(compilerOptions.allowEmptyCodegenFiles).toBe(false);
+    expect(compilerOptions.annotationsAs).toBe('decorators');
+    expect(compilerOptions.enableResourceInlining).toBe(false);
+    expect(compilerOptions.allowJs).toBe(true);
+  });
+});

src/__tests__/ng-jest-transformer.spec.ts

@@ -1,4 +1,5 @@
 import { NgJestCompiler } from '../compiler/ng-jest-compiler';
+import { NgJestConfig } from '../config/ng-jest-config';
 import { NgJestTransformer } from '../ng-jest-transformer';
 
 describe('NgJestTransformer', () => {
@@ -18,6 +19,7 @@ describe('NgJestTransformer', () => {
 
       // @ts-expect-error testing purpose
       expect(tr._compiler).toBeInstanceOf(NgJestCompiler);
+      expect(cs).toBeInstanceOf(NgJestConfig);
     });
   });
 });

src/config/ng-jest-config.ts

@@ -0,0 +1,22 @@
+import { ConfigSet } from 'ts-jest/dist/config/config-set';
+import type { RawCompilerOptions } from 'ts-jest/dist/raw-compiler-options';
+import type { ParsedCommandLine } from 'typescript';
+
+export class NgJestConfig extends ConfigSet {
+  /**
+   * Override `ts-jest` behavior because we use `readConfiguration` which will read and resolve tsconfig.
+   */
+  protected _resolveTsConfig(compilerOptions?: RawCompilerOptions, resolvedConfigFile?: string): ParsedCommandLine {
+    const result = super._resolveTsConfig(compilerOptions, resolvedConfigFile);
+    result.options.enableIvy = true;
+    result.options.noEmitOnError = false;
+    result.options.suppressOutputPathCheck = true;
+    result.options.allowEmptyCodegenFiles = false;
+    result.options.annotationsAs = 'decorators';
+    result.options.enableResourceInlining = false;
+    // Since we define preset default also transform `js` so we need to set `allowJs` true
+    result.options.allowJs = true;
+
+    return result as ParsedCommandLine;
+  }
+}

src/ng-jest-transformer.ts

@@ -1,9 +1,15 @@
 import { ConfigSet } from 'ts-jest/dist/config/config-set';
 import { TsJestTransformer } from 'ts-jest/dist/ts-jest-transformer';
+import type { ProjectConfigTsJest } from 'ts-jest/dist/types';
 
 import { NgJestCompiler } from './compiler/ng-jest-compiler';
+import { NgJestConfig } from './config/ng-jest-config';
 
 export class NgJestTransformer extends TsJestTransformer {
+  protected _createConfigSet(config: ProjectConfigTsJest | undefined): ConfigSet {
+    return new NgJestConfig(config);
+  }
+
   protected _createCompiler(configSet: ConfigSet, cacheFS: Map<string, string>): void {
     this._compiler = new NgJestCompiler(configSet, cacheFS);
   }

tsconfig.spec.json

@@ -2,7 +2,6 @@
   "extends": "./tsconfig.json",
   "compilerOptions": {
     "allowSyntheticDefaultImports": true,
-    "esModuleInterop": true,
-    "allowJs": true
+    "esModuleInterop": true
   }
 }