CODEWITHSUNDEEP
typescriptasync-awaitjestjsexpected-exception
malarres
malarres

Reputation: 2946

Test with UnhandledPromiseRejectionWarning but passing

I'm testing whether a xml2js is returning the same JS as expected. If I run the code when the expected is equal to the received, I get no errors. However, if I run the code when there are differences, I get:

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        7.199 s, estimated 8 s
Ran all test suites matching /create/i.
  console.error
    expect(received).resolves.toEqual(expected) // deep equality

So the console is able to tell me that something is not ok, but the test suite thinks everything worked well.

      it('converts xml to JS', async () => {
     try {
        fs.readFile(__dirname + '/' + bpmnxml, 'utf8', async (err, data) => {
           if (err) {
              console.error(err);
           } else {
              try {
                 await expect(parseXML(data)).resolves.toEqual(bpmnjson);
              } catch (errExpect) {
                 console.error(errExpect.message);
                 // eslint-disable-next-line jest/no-try-expect
                 // return expect(errExpect).toEqual(new Error('error on expect'));
              }
           }
        });
     } catch (errReadFile) {
        console.error(errReadFile);
     }
  });

If I uncomment the // return expect(errExpect).toEqual(new Error('error on expect')); then I get this other error:

(node:28424) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:28424) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

But the test suite still says that it passed.

What can I do to force an error (so that I get a Test Fail) but I don't get this UnhandledPromiseRejectionWarning? The try-catch blocks are not handling this.

Upvotes: 2

Views: 1078

Answers (1)

malarres
malarres

Reputation: 2946

It was likely related to fs.readFile , as its synchronous version works for me:

   it('converts xml to JS', async () => {
      const data = fs.readFileSync(__dirname + '/' + bpmnxml, 'utf8');
      expect.hasAssertions();
      await expect(parseXML(data)).resolves.toEqual(bpmnjson);
   });

When they should be equal:

    √ converts xml to JS (16 ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        3.069 s, estimated 4 s

When I make a random change in one of them:

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 total
Snapshots:   0 total
Time:        3.247 s, estimated 4 s

Upvotes: 1

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