使用 Jest 检查数组相等性

Question

我在文件 test.ts 中有一个方法：

public async listComponentsDiffer(lastTag: string, workDir: string): Promise<any[]> 

这个方法返回一个像这样的数组：

[{ components: "toto", newVersion: "2", oldVersion: "1" }]

我正在尝试使用 Jest，我这样做是为了检查此方法：

test("correct array form", () => {
    // Given
    const lastag = "";
    const workDir = ".";

    // When
    const result = ComponentsService.listComponentsDiffer(lastag, workDir);

    // Then
    const expected = [{ components: "toto", newVersion: "2", oldVersion: "1" }];
    expect(result).toBe(expected);
});

但我有这个错误：

TypeError: test_1.test.listComponentsDiffer is not a function Jest

我该如何进行测试？

Answer 1

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1. 该方法是实例方法，而不是类静态方法。需要从类的实例中调用。

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2. 该方法使用async/await语法，需要添加async/await到您的测试用例中。

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3. .toBe您应该使用而不是使用.toEqual使用。

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使用 .toEqual 递归比较对象实例的所有属性（也称为“深度”相等）

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例如

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test.ts:

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export class ComponentsService {\n  public async listComponentsDiffer(lastTag: string, workDir: string): Promise<any[]> {\n    return [{ components: \'toto\', newVersion: \'2\', oldVersion: \'1\' }];\n  }\n}\n

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test.test.ts:

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import { ComponentsService } from \'./test\';\n\ndescribe(\'60667611\', () => {\n  test(\'correct array form\', async () => {\n    const lastag = \'\';\n    const workDir = \'.\';\n    const instance = new ComponentsService();\n\n    const result = await instance.listComponentsDiffer(lastag, workDir);\n\n    const expected = [{ components: \'toto\', newVersion: \'2\', oldVersion: \'1\' }];\n    expect(result).toEqual(expected);\n  });\n});\n

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单元测试结果：

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 PASS  stackoverflow/60667611/test.test.ts (7.968s)\n  60667611\n    \xe2\x9c\x93 correct array form (6ms)\n\nTest Suites: 1 passed, 1 total\nTests:       1 passed, 1 total\nSnapshots:   0 total\nTime:        9.014s\n

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