运行测试后我得到了一个无聊的堆栈跟踪。我从这些问题中尝试过诸如
fakeTimersrequire('iconv-lite')...ReferenceError：您正在尝试在 Jest 环境被拆除后“导入”文件
据我了解，在我的测试完成后，某些东西仍在运行。我是打字稿和 NodeJS 的新手，所以我需要一些帮助来理解和解决这个问题。
这是错误（在我的代码下方）：
ReferenceError: You are trying to `import` a file after the Jest environment has been torn down. From src/TESTE/repository.test.ts.
at Object.getCodec (node_modules/mysql2/node_modules/iconv-lite/lib/index.js:63:27)
at Object.getDecoder (node_modules/mysql2/node_modules/iconv-lite/lib/index.js:125:23)
at Object.<anonymous>.exports.decode (node_modules/mysql2/lib/parsers/string.js:10:25)
at Packet.readNullTerminatedString (node_modules/mysql2/lib/packets/packet.js:412:25)
at Function.fromPacket (node_modules/mysql2/lib/packets/handshake.js:62:33)
at ClientHandshake.handshakeInit (node_modules/mysql2/lib/commands/client_handshake.js:112:40)
at ClientHandshake.execute (node_modules/mysql2/lib/commands/command.js:45:22)
at Connection.handlePacket (node_modules/mysql2/lib/connection.js:478:34)
at PacketParser.onPacket (node_modules/mysql2/lib/connection.js:97:12)
at PacketParser.executeStart (node_modules/mysql2/lib/packet_parser.js:75:16)
at Socket.<anonymous> (node_modules/mysql2/lib/connection.js:104:25)
node:events:505
throw err; // Unhandled 'error' event
^
Error: Unhandled error. (Error: Encoding not recognized: 'cesu8' (searched as: 'cesu8')
at Object.getCodec (/Users/patrick/my-app/node_modules/mysql2/node_modules/iconv-lite/lib/index.js:104:23)
at Object.getDecoder (/Users/patrick/my-app/node_modules/mysql2/node_modules/iconv-lite/lib/index.js:125:23)
at Object.<anonymous>.exports.decode (/Users/patrick/my-app/node_modules/mysql2/lib/parsers/string.js:10:25)
at Packet.readNullTerminatedString (/Users/patrick/my-app/node_modules/mysql2/lib/packets/packet.js:412:25)
at Function.fromPacket (/Users/patrick/my-app/node_modules/mysql2/lib/packets/handshake.js:62:33)
at ClientHandshake.handshakeInit (/Users/patrick/my-app/node_modules/mysql2/lib/commands/client_handshake.js:112:40)
at ClientHandshake.execute (/Users/patrick/my-app/node_modules/mysql2/lib/commands/command.js:45:22)
at Connection.handlePacket (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:478:34)
at PacketParser.onPacket (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:97:12)
at PacketParser.executeStart (/Users/patrick/my-app/node_modules/mysql2/lib/packet_parser.js:75:16)
at Socket.<anonymous> (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:104:25)
at Socket.emit (node:events:514:28)
at addChunk (node:internal/streams/readable:343:12)
at readableAddChunk (node:internal/streams/readable:316:9)
at Socket.Readable.push (node:internal/streams/readable:253:10)
at TCP.onStreamRead (node:internal/stream_base_commons:190:23) {
fatal: true
})
at new NodeError (node:internal/errors:405:5)
at Connection.emit (node:events:503:17)
at Connection._notifyError (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:252:12)
at Connection._handleFatalError (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:183:10)
at Connection.handlePacket (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:488:12)
at PacketParser.onPacket (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:97:12)
at PacketParser.executeStart (/Users/patrick/my-app/node_modules/mysql2/lib/packet_parser.js:75:16)
at Socket.<anonymous> (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:104:25)
at Socket.emit (node:events:514:28)
at addChunk (node:internal/streams/readable:343:12)
at readableAddChunk (node:internal/streams/readable:316:9)
at Socket.Readable.push (node:internal/streams/readable:253:10)
at TCP.onStreamRead (node:internal/stream_base_commons:190:23) {
code: 'ERR_UNHANDLED_ERROR',
context: Error: Encoding not recognized: 'cesu8' (searched as: 'cesu8')
at Object.getCodec (/Users/patrick/my-app/node_modules/mysql2/node_modules/iconv-lite/lib/index.js:104:23)
at Object.getDecoder (/Users/patrick/my-app/node_modules/mysql2/node_modules/iconv-lite/lib/index.js:125:23)
at Object.<anonymous>.exports.decode (/Users/patrick/my-app/node_modules/mysql2/lib/parsers/string.js:10:25)
at Packet.readNullTerminatedString (/Users/patrick/my-app/node_modules/mysql2/lib/packets/packet.js:412:25)
at Function.fromPacket (/Users/patrick/my-app/node_modules/mysql2/lib/packets/handshake.js:62:33)
at ClientHandshake.handshakeInit (/Users/patrick/my-app/node_modules/mysql2/lib/commands/client_handshake.js:112:40)
at ClientHandshake.execute (/Users/patrick/my-app/node_modules/mysql2/lib/commands/command.js:45:22)
at Connection.handlePacket (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:478:34)
at PacketParser.onPacket (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:97:12)
at PacketParser.executeStart (/Users/patrick/my-app/node_modules/mysql2/lib/packet_parser.js:75:16)
at Socket.<anonymous> (/Users/patrick/my-app/node_modules/mysql2/lib/connection.js:104:25)
at Socket.emit (node:events:514:28)
at addChunk (node:internal/streams/readable:343:12)
at readableAddChunk (node:internal/streams/readable:316:9)
at Socket.Readable.push (node:internal/streams/readable:253:10)
at TCP.onStreamRead (node:internal/stream_base_commons:190:23) {
fatal: true
}
}
我的代码：
repository.ts import connection from "../db";
import { RowDataPacket } from "mysql2"
interface ITestRepository {
doSomething(value: number): Promise<ResultObject>;
}
interface ResultObject extends RowDataPacket {
value: number;
}
class MyRepository implements ITestRepository {
doSomething(value: number): Promise<ResultObject> {
let query: string = `select * from SOMETABLE`;
return new Promise((resolve, reject) => {
connection.query<ResultObject[]>(query, (err, res) => {
if (err) reject(err);
else resolve(res[0]);
});
});
}
}
export default new MyRepository();
最后是我的测试：
repository.test.tsimport MyRepository from './repository';
import connection from "../db";
jest.mock('../config/db.config');
describe('RepoTest', () => {
const mockQuery = jest.fn();
beforeAll(() => {
connection.query = mockQuery;
});
afterEach(() => {
mockQuery.mockReset();
});
describe('something', () => {
it('should calculate something', async () => {
const value = 10;
const expectedResult = [{ result: 2.0 }];
mockQuery.mockImplementationOnce((query, callback) => {
callback(null, expectedResult);
});
const result = await MyRepository.doSomething(value);
expect(mockQuery).toHaveBeenCalledTimes(1);
expect(result).toEqual(expectedResult[0]);
});
});
});
另外还有两个与数据库相关的文件：
db/index.tsimport mysql from "mysql2";
import dbConfig from "../config/db.config";
export default mysql.createConnection({
host: dbConfig.HOST,
user: dbConfig.USER,
password: dbConfig.PASSWORD,
database: dbConfig.SCHEMA
});
config/ds.config.tsexport default {
HOST: process.env.DB_HOST ? process.env.DB_HOST : "XXX",
USER: process.env.DB_USER ? process.env.DB_USER : "XXX",
PASSWORD: process.env.DB_PASSWORD ? process.env.DB_PASSWORD : "XXX",
SCHEMA: process.env.DB_SCHEMA ? process.env.DB_SCHEMA : "XXX"
};
使用 Jest 测试异步代码有多种技术。
在您的情况下，从
doSomething()从链接中，
.resolves尝试改变：
expect(result).toEqual(expectedResult[0])至：
expect(result).resolves.toEqual(expectedResult[0])对于测试失败案例，还有
.rejects