要进行Angular 9表单模块的单元测试，可以使用Jasmine和Karma进行测试。下面是一个包含代码示例的解决方案：

1. 首先，安装所需的测试工具：

npm install --save-dev @angular-devkit/build-angular karma karma-chrome-launcher karma-cli karma-jasmine karma-jasmine-html-reporter

2. 在项目根目录下创建一个karma.conf.js文件，并添加以下配置：

// karma.conf.js
module.exports = function(config) {
  config.set({
    basePath: '',
    frameworks: ['jasmine', '@angular-devkit/build-angular'],
    plugins: [
      require('karma-jasmine'),
      require('karma-chrome-launcher'),
      require('karma-jasmine-html-reporter'),
      require('@angular-devkit/build-angular/plugins/karma')
    ],
    client: {
      clearContext: false // leave Jasmine Spec Runner output visible in browser
    },
    coverageIstanbulReporter: {
      dir: require('path').join(__dirname, './coverage/angular-app'),
      reports: ['html', 'lcovonly', 'text-summary'],
      fixWebpackSourcePaths: true
    },
    reporters: ['progress', 'kjhtml'],
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['Chrome'],
    singleRun: false,
    restartOnFileChange: true
  });
};

3. 创建一个简单的表单组件app-form.component.ts：

// app-form.component.ts
import { Component } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'app-form',
  template: `
    

      
      Submit
    
  `
})
export class AppFormComponent {
  form: FormGroup;

  constructor(private formBuilder: FormBuilder) {
    this.form = this.formBuilder.group({
      name: ['', Validators.required]
    });
  }

  onSubmit() {
    if (this.form.valid) {
      console.log('Form submitted');
    }
  }
}

4. 创建一个测试文件app-form.component.spec.ts，在其中编写测试用例：

// app-form.component.spec.ts
import { TestBed, ComponentFixture } from '@angular/core/testing';
import { ReactiveFormsModule } from '@angular/forms';
import { AppFormComponent } from './app-form.component';

describe('AppFormComponent', () => {
  let component: AppFormComponent;
  let fixture: ComponentFixture;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [ReactiveFormsModule],
      declarations: [AppFormComponent]
    }).compileComponents();

    fixture = TestBed.createComponent(AppFormComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create a form with a name control', () => {
    expect(component.form.controls['name']).toBeTruthy();
  });

  it('should make the form invalid when empty', () => {
    expect(component.form.valid).toBeFalsy();
  });

  it('should make the form valid when a name is entered', () => {
    const nameControl = component.form.controls['name'];
    nameControl.setValue('John Doe');
    expect(component.form.valid).toBeTruthy();
  });

  it('should call onSubmit method when form is submitted', () => {
    spyOn(component, 'onSubmit');
    const formEl = fixture.nativeElement.querySelector('form');
    formEl.dispatchEvent(new Event('submit'));
    fixture.detectChanges();
    expect(component.onSubmit).toHaveBeenCalled();
  });
});

5. 运行测试：

ng test

这样就可以运行你的Angular 9表单模块的单元测试了。