Purpose:

Test controller method with file stream response.

Controller:

@Get('/resources/pdf/:fileId')
@HttpCode(HttpStatus.OK)
public async downloadPdf(
    @Param('fileId') fileId: string,
@Res() response: Response
): Promise<void> {
    const fileReadableStream = await myService.downloadPdf(fileId);
    response.setHeader('Content-Type', 'application/pdf');
    fileReadableStream.pipe(response);
}

Test unit:

describe('FileDownloadController', () => {
    it('should download file with specific header', async () => {
        await request(app.getHttpServer())
            .get('/resources/pdf/myFileId')
            .expect(200)
            .expect('Content-Type', 'application/pdf')
            .expect('my file content');
    });
});

CodePudding user response：

• Create stream from any data
• expect a buffer as response body

import { Buffer } from 'buffer';
import { Readable } from 'stream';

describe('FileDownloadController', () => {
    let myMockService: MockProxy<MyService> & MyService;

    it('should download file with specific header', async () => {
        const body = Buffer.from('my file content');
        const mockReadableStream = Readable.from(body);

        myMockService.downloadPdf.calledWith('myFileId').mockResolvedValue(mockReadableStream);

        await request(app.getHttpServer())
            .get('/resources/pdf/myFileId')
            .expect(200)
            .expect('Content-Type', 'application/pdf')
            .expect(body);
    });
});