jest/no-conditional-in-test Pedantic

What it does

Disallow conditional statements in tests.

Why is this bad?

Conditional statements in tests can make the test harder to read and understand. It is better to have a single test case per test function.

Examples

Examples of incorrect code for this rule:

it("foo", () => {
  if (true) {
    doTheThing();
  }
});

it("bar", () => {
  switch (mode) {
    case "none":
      generateNone();
    case "single":
      generateOne();
    case "multiple":
      generateMany();
  }

  expect(fixtures.length).toBeGreaterThan(-1);
});

it("baz", async () => {
  const promiseValue = () => {
    return something instanceof Promise
      ? something
      : Promise.resolve(something);
  };

  await expect(promiseValue()).resolves.toBe(1);
});

Examples of correct code for this rule:

describe("my tests", () => {
  if (true) {
    it("foo", () => {
      doTheThing();
    });
  }
});

beforeEach(() => {
  switch (mode) {
    case "none":
      generateNone();
    case "single":
      generateOne();
    case "multiple":
      generateMany();
  }
});

it("bar", () => {
  expect(fixtures.length).toBeGreaterThan(-1);
});

const promiseValue = something => {
  return something instanceof Promise ? something : Promise.resolve(something);
};

it("baz", async () => {
  await expect(promiseValue()).resolves.toBe(1);
});

How to use

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

CLI

oxlint --deny jest/no-conditional-in-test --jest-plugin

Config (.oxlintrc.json)

{
  "plugins": ["jest"],
  "rules": {
    "jest/no-conditional-in-test": "error"
  }
}

References

• Rule Source