1.6 KiB
No standalone expect in a describe block (no-standalone-expect)
Prevents expect
statements outside of a test
or it
block. An expect
within a helper function (but outside of a test
or it
block) will not
trigger this rule.
Rule Details
This rule aims to eliminate expect
statements that will not be executed. An
expect
inside of a describe
block but outside of a test
or it
block or
outside of a describe
will not execute and therefore will trigger this rule.
It is viable, however, to have an expect
in a helper function that is called
from within a test
or it
block so expect
statements in a function will not
trigger this rule.
Statements like expect.hasAssertions()
will NOT trigger this rule since these
calls will execute if they are not in a test block.
Examples of incorrect code for this rule:
// in describe
describe('a test', () => {
expect(1).toBe(1);
});
// below other tests
describe('a test', () => {
it('an it', () => {
expect(1).toBe(1);
});
expect(1).toBe(1);
});
Examples of correct code for this rule:
// in it block
describe('a test', () => {
it('an it', () => {
expect(1).toBe(1);
});
});
// in helper function
describe('a test', () => {
const helper = () => {
expect(1).toBe(1);
};
it('an it', () => {
helper();
});
});
describe('a test', () => {
expect.hasAssertions(1);
});
*Note that this rule will not trigger if the helper function is never used even
thought the expect
will not execute. Rely on a rule like no-unused-vars for
this case.
When Not To Use It
Don't use this rule on non-jest test files.