feat(ngMocks): allows to suppress console logs #578

docs/articles/api/ngMocks.md

@@ -62,6 +62,7 @@ access desired elements and instances in fixtures.
 
 - [`guts()`](ngMocks/guts.md)
 - [`faster()`](ngMocks/faster.md)
+- [`ignoreOnConsole()`](ngMocks/ignoreOnConsole.md)
 - [`throwOnConsole()`](ngMocks/throwOnConsole.md)
 - [`formatHtml()`](ngMocks/formatHtml.md)
 - [`formatText()`](ngMocks/formatText.md)

docs/articles/api/ngMocks/ignoreOnConsole.md

@@ -0,0 +1,14 @@
+---
+title: ngMocks.ignoreOnConsole
+description: A way to suppress console logs in Angular unit tests
+---
+
+`ngMocks.ignoreOnConsole` suppresses `console.log` with a spy (if [auto spy](../../extra/auto-spy.md) is being used).
+
+`ngMocks.ignoreOnConsole` suppresses the functions for the current test suite in `beforeAll` and restores in `afterAll`.
+
+Also, any other methods can be stubbed:
+
+```ts
+ngMocks.ignoreOnConsole('log', 'err', 'warn');
+```

docs/articles/api/ngMocks/throwOnConsole.md

@@ -3,5 +3,13 @@ title: ngMocks.throwOnConsole
 description: Documentation about ngMocks.throwOnConsole from ng-mocks library
 ---
 
-`ngMocks.throwOnConsole` stubs `console.warn` and `console.error` to throw an error instead of printing into the console.
-It is useful in `Ivy` enabled mode, because then some errors are printed instead of being thrown.
+`ngMocks.throwOnConsole` stubs `console.warn` and `console.error` to throw an error instead of printing it into the console.
+It is useful in `Ivy` enabled mode, because some errors are printed via `console` instead of being thrown.
+
+`ngMocks.throwOnConsole` stubs the functions for the current test suite in `beforeAll` and restores in `afterAll`.
+
+Also, any other methods can be stubbed:
+
+```ts
+ngMocks.throwOnConsole('log');
+```

docs/sidebars.js

@@ -59,6 +59,7 @@ module.exports = {
         'api/ngMocks/stubMember',
         'api/ngMocks/guts',
         'api/ngMocks/faster',
+        'api/ngMocks/ignoreOnConsole',
         'api/ngMocks/throwOnConsole',
         'api/ngMocks/formatHtml',
         'api/ngMocks/formatText',

libs/ng-mocks/src/lib/mock-helper/mock-helper.ignore-on-console.ts

@@ -0,0 +1,27 @@
+// tslint:disable no-console
+
+import helperMockService from '../mock-service/helper.mock-service';
+
+const factory = (propName: string) => helperMockService.mockFunction(`console.${propName}`);
+
+// Thanks Ivy, it does not throw an error and we have to use injector.
+export default (...methods: Array<keyof typeof console>): void => {
+  const backup: Array<[keyof typeof console, any]> = [];
+
+  beforeAll(() => {
+    if (methods.indexOf('log') === -1) {
+      methods.push('log');
+    }
+    for (const method of methods) {
+      backup.push([method, console[method]]);
+      console[method] = factory(method);
+    }
+  });
+
+  afterAll(() => {
+    for (const [method, implementation] of backup) {
+      console[method] = implementation;
+    }
+    backup.splice(0, backup.length);
+  });
+};

libs/ng-mocks/src/lib/mock-helper/mock-helper.object.ts

@@ -26,6 +26,7 @@ import mockHelperGlobalMock from './mock-helper.global-mock';
 import mockHelperGlobalReplace from './mock-helper.global-replace';
 import mockHelperGlobalWipe from './mock-helper.global-wipe';
 import mockHelperGuts from './mock-helper.guts';
+import mockHelperIgnoreOnConsole from './mock-helper.ignore-on-console';
 import mockHelperInput from './mock-helper.input';
 import mockHelperOutput from './mock-helper.output';
 import mockHelperReset from './mock-helper.reset';
@@ -78,6 +79,7 @@ export default {
   globalWipe: mockHelperGlobalWipe,
   guts: mockHelperGuts,
   hide: mockHelperHide,
+  ignoreOnConsole: mockHelperIgnoreOnConsole,
   input: mockHelperInput,
   output: mockHelperOutput,
   render: mockHelperRender,

libs/ng-mocks/src/lib/mock-helper/mock-helper.ts

@@ -342,6 +342,13 @@ export const ngMocks: {
    */
   hide(instance: object, directive: object): void;
 
+  /**
+   * it suppresses any log calls, other methods can be suppressed too.
+   *
+   * @see https://ng-mocks.sudo.eu/api/ngMocks/ignoreOnConsole
+   */
+  ignoreOnConsole(...args: Array<keyof typeof console>): void;
+
   /**
    * @see https://ng-mocks.sudo.eu/api/ngMocks/input
    */

tests/ng-mocks-ignore-on-console/test.spec.ts

@@ -0,0 +1,66 @@
+// tslint:disable no-console
+
+import { ngMocks } from 'ng-mocks';
+
+describe('ng-mocks-ignore-on-console', () => {
+  describe('default', () => {
+    let original: any;
+    beforeAll(() => (original = console.log));
+
+    describe('override', () => {
+      ngMocks.ignoreOnConsole();
+
+      it('replaces the log with a spy', () => {
+        expect(console.log).not.toBe(original);
+        console.log('test');
+        expect(console.log).toHaveBeenCalledWith('test');
+      });
+    });
+
+    it('restores the original console.log', () => {
+      expect(console.log).toBe(original);
+    });
+  });
+
+  describe('custom', () => {
+    let original: any;
+    beforeAll(() => (original = console.warn));
+
+    describe('override', () => {
+      ngMocks.ignoreOnConsole('warn');
+
+      it('replaces the log with a spy', () => {
+        expect(console.warn).not.toBe(original);
+        console.warn('test');
+        expect(console.log).not.toHaveBeenCalled();
+        expect(console.warn).toHaveBeenCalledWith('test');
+      });
+    });
+
+    it('restores the original console.log', () => {
+      expect(console.warn).toBe(original);
+    });
+  });
+
+  describe('restore', () => {
+    let originalLog: any;
+    beforeAll(() => (originalLog = console.log));
+    let originalWarn: any;
+    beforeAll(() => (originalWarn = console.warn));
+
+    describe('override', () => {
+      ngMocks.ignoreOnConsole('log', 'warn');
+      ngMocks.throwOnConsole('log', 'warn');
+
+      it('replaces the log with a spy', () => {
+        expect(console.log).not.toBe(originalLog);
+        expect(console.warn).not.toBe(originalWarn);
+      });
+    });
+
+    it('restores the original console.log', () => {
+      expect(console.log).toBe(originalLog);
+      expect(console.warn).toBe(originalWarn);
+    });
+  });
+});