在Angular 7中解决Jasmine单元测试中的Hammer.js依赖问题，可以采取以下步骤：

1. 在项目的根目录下，创建一个mocks文件夹，并在其中创建一个hammer.mock.ts文件。这将用于模拟Hammer.js的依赖。

2. 在hammer.mock.ts文件中添加以下代码：

export class HammerMock {
  on(eventName: string, callback: Function) {}
  off(eventName: string, callback: Function) {}
  destroy() {}
}

export class HammerInstance {
  recognize() {}
}

export class HammerStatic {
  constructor(element: HTMLElement | string, options?: any) {}
  on(eventName: string, callback: Function) {}
  off(eventName: string, callback: Function) {}
  set(options: any) {}
  get(options: any) {}
  emit(eventName: string, eventData: any) {}
  destroy() {}
}

export const Hammer = {
  Instance: HammerInstance,
  Static: HammerStatic,
  mock: HammerMock
};

3. 在要测试的组件文件中，将对Hammer.js的依赖更改为对hammer.mock.ts的引用。例如，如果你的组件文件中有以下代码：

import { HammerGestureConfig, HAMMER_GESTURE_CONFIG } from '@angular/platform-browser';
import * as Hammer from 'hammerjs';

export class CustomHammerConfig extends HammerGestureConfig {
  buildHammer(element: HTMLElement) {
    const mc = new Hammer(element);
    // 执行相关操作
    return mc;
  }
}

@NgModule({
  providers: [
    {
      provide: HAMMER_GESTURE_CONFIG,
      useClass: CustomHammerConfig
    }
  ]
})
export class AppModule {}

你需要将import * as Hammer from 'hammerjs';更改为import { Hammer } from '../mocks/hammer.mock';。

4. 在你的单元测试文件中，添加以下代码来模拟Hammer.js的依赖：

import { Hammer } from '../mocks/hammer.mock';

beforeEach(() => {
  spyOn(Hammer, 'Instance').and.returnValue({
    on: (eventName: string, callback: Function) => {},
    off: (eventName: string, callback: Function) => {},
    recognize: () => {},
    destroy: () => {}
  });

  spyOn(Hammer, 'Static').and.returnValue({
    on: (eventName: string, callback: Function) => {},
    off: (eventName: string, callback: Function) => {},
    set: (options: any) => {},
    get: (options: any) => {},
    emit: (eventName: string, eventData: any) => {},
    destroy: () => {}
  });

  spyOn(Hammer, 'mock').and.returnValue({
    on: (eventName: string, callback: Function) => {},
    off: (eventName: string, callback: Function) => {},
    destroy: () => {}
  });
});

这将模拟Hammer.js中的相关方法，并将它们的实现更改为空函数。

现在，你就可以在Angular 7中解决Jasmine单元测试中的Hammer.js依赖问题了。