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vitest/prefer-to-have-been-called-times Style

🛠️ An auto-fix is available for this rule.

What it does

In order to have a better failure message, toHaveBeenCalledTimes should be used instead of directly checking the length of mock.calls.

Why is this bad?

This rule triggers a warning if toHaveLength is used to assert the number of times a mock is called.

Examples

Examples of incorrect code for this rule:

expect(someFunction.mock.calls).toHaveLength(1);
expect(someFunction.mock.calls).toHaveLength(0);
expect(someFunction.mock.calls).not.toHaveLength(1);

Examples of correct code for this rule:

expect(someFunction).toHaveBeenCalledTimes(1);
expect(someFunction).toHaveBeenCalledTimes(0);
expect(someFunction).not.toHaveBeenCalledTimes(0);
expect(uncalledFunction).not.toBeCalled();
expect(method.mock.calls[0][0]).toStrictEqual(value);

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "plugins": ["vitest"],
  "rules": {
    "vitest/prefer-to-have-been-called-times": "error"
  }
}

Config (oxlint.config.ts)

import { defineConfig } from "oxlint";

export default defineConfig({
  plugins: ["vitest"],
  rules: {
    "vitest/prefer-to-have-been-called-times": "error",
  },
});

CLI

oxlint --deny vitest/prefer-to-have-been-called-times --vitest-plugin

Version

This rule was added in v1.34.0.

References

• Rule Source
• Open rule in Oxc Playground