Intention of global aliases

[tbartley]

Hi,

I often define my own conditional implementations of describe or it where I might have something like:

let relevantTests = describe.skip
if (env.THESE_TESTS_ARE_RELEVANT) {
  relevantTests = describe
}

relevantTests('run the relevant tests', () => {
  it('should ...)
})

so I tried setting relevantTests as a global alias for describe in settings but it is ignored because of this code in resolveToJestFn in src/rules/utils/parseJestFnCall.ts:

  // the identifier was found as a local variable or function declaration
  // meaning it's not a function from jest
  if (references.locals.has(identifier)) {
    return null;
  }

If I remove that code then my aliased describe function is correctly identified as an alias for describe.

I'm happy to submit a PR but clearly that code was deliberately added for a reason and just removing it may not be the right solution. Or maybe my understanding of the purpose of the globalAliases setting is incorrect.

Cheers,

Tim

[tbartley]

A more complete example as to why this causes an issue for me would be a pattern like:

let relevantTests = describe.skip
if (env.THESE_TESTS_ARE_RELEVANT) {
  relevantTests = describe
}

let otherRelevantTests = describe.skip
if (env.THESE_OTHER_TESTS_ARE_RELEVANT) {
  otherRelevantTests = describe
}

describe('full test suite', () => {
  relevantTests('run the relevant tests', () => {
    it('should behave like this', () = {
       ...
    })
  })

  otherRelevantTests('run the other relevant tests', () => {
    it('should behave like this', () = {
       ...
    })
  })
})

In the above case I have a test in each aliased describe section with the same name. Because my alias is not picked up as a describe alias, I get a "duplicate title" error as the tests in each sub-suite have the same title.

This scenario is when I'm using jest to run system tests against different environments where one, both or none of the above sub-suites may be relevant in any given environment.

I was hoping I could simply add the following settings to my .eslintrc.js to resolve:

{
   settings: {
     jest: {
       globalAliases: {
          describe: [ 'relevantTests', 'otherRelevantTests' ]
        }
     }
   }
}

[G-Rath]

It's because it expects them to be global aliases - I'm not really that comfortable with extending this support out further given its already a stretch and you can resolve this by creating a setup file that assigns global.relevantTests = describe.skip.

See #83 and jestjs/jest#2468 (comment) for more

There's a few ways you can agree your advance case, such as having a function global (i.e. enableTheseTests('key');) or something like:

const runTestsIf = (condition, tests) => {
  if (condition()) {
    tests();
  }
};

describe("full test suite", () => {
  runTestsIf(
    () => env.THESE_TESTS_ARE_RELEVANT,
    () => {
      describe("run the other relevant tests", () => {
        it("should behave like this", () => {
          // ...
        });
      });
    }
  );

  runTestsIf(
    () => env.THESE_OTHER_TESTS_ARE_RELEVANT,
    () => {
      describe("run the other relevant tests", () => {
        it("should behave like this", () => {
          // ...
        });
      });
    }
  );
});

[tbartley]

Thanks Gareth, I can look at other approaches to my needs that dont interfere as you suggest.