jest/no-conditional-expect Correctness
What it does
This rule prevents the use of expect in conditional blocks, such as ifs & catch(s). This includes using expect in callbacks to functions named catch, which are assumed to be promises.
Why is this bad?
Jest only considers a test to have failed if it throws an error, meaning if calls to assertion functions like expect occur in conditional code such as a catch statement, tests can end up passing but not actually test anything. Additionally, conditionals tend to make tests more brittle and complex, as they increase the amount of mental thinking needed to understand what is actually being tested.
Example
javascript
it("foo", () => {
doTest && expect(1).toBe(2);
});
it("bar", () => {
if (!skipTest) {
expect(1).toEqual(2);
}
});
it("throws an error", async () => {
await foo().catch((error) => expect(error).toBeInstanceOf(error));
});This rule is compatible with eslint-plugin-vitest, to use it, add the following configuration to your .eslintrc.json:
json
{
"rules": {
"vitest/no-conditional-expect": "error"
}
}