TypeError: Cannot read property 'toString' of undefined at ActivityTracker.shouldTrack

[nbarrett]

I've been happily running my specs for a few days and suddenly I'm now having this problem and I have no idea why:

[12:12:50] I/launcher - Running 1 instances of WebDriver

[12:12:50] I/direct - Using ChromeDriver directly...

 0 passing (74ms)
  1 failing
  1) Walks and Events Manager walk upload:
     TypeError: Cannot read property \'toString\' of undefined
      at ActivityTracker.shouldTrack (node_modules/@serenity-js/core/src/screenplay/actor.ts:96:59)
      at ActivityTracker.track (node_modules/@serenity-js/core/src/screenplay/actor.ts:91:42)
      at Array.map (native)
      at Actor.attemptsTo (node_modules/@serenity-js/core/src/screenplay/actor.ts:68:27)
      at Context.<anonymous> (client/spec/features/walks-upload.ts:20:22)
      at runTest (node_modules/serenity-js/src/serenity-mocha/controlflow.ts:96:32)
      at node_modules/serenity-js/src/serenity-mocha/controlflow.ts:117:24
      at new ManagedPromise (node_modules/selenium-webdriver/lib/promise.js:1067:7)
      at controlFlowExecute (node_modules/serenity-js/src/serenity-mocha/controlflow.ts:116:20)
      at TaskQueue.execute_ (node_modules/selenium-webdriver/lib/promise.js:2970:14)
  From: Task: Walks and Events Manager walk upload
      at Context.ret (node_modules/serenity-js/src/serenity-mocha/controlflow.ts:115:14)

[12:12:52] I/launcher - 0 instance(s) of   WebDriver still running

[12:12:52]   E/launcher - Process exited with error code 1

[12:12:52] I/launcher - chrome #01 failed 1   test(s) [12:12:52] I/launcher - overall: 1 failed spec(s) 

Error: ERR! Darwin 16.7.0 npm ERR! argv   "/Users/nick/.nvm/versions/node/v6.11.3/bin/node"   "/Users/nick/.nvm/versions/node/v6.11.3/bin/npm" "run"   "e2e" npm ERR! node v6.11.3 npm ERR! npm v3.10.10 npm ERR! code   ELIFECYCLE npm ERR! ekwg@0.0.1 e2e: `protractor ./protractor.conf.js` npm   ERR! Exit status 1 npm ERR!

I can't even find out what part of my code I'm running as there is none of my code in the stack trace.

I've also tried adding/removing the crew as I don't actually need them on this project (which is a screen-scraping application), but it doesn't make any difference. Any thoughts please @jan-molak ?

[nbarrett]

Found it after about 12 hours of head-scratching!! I used to have this static method:

static requested() {
        const walkParameters = RequestParameterExtractor.extract();
        return new DeleteWalksWithIds(walkParameters.walkDeletions);
    }

However I changed this method to be conditional as follows:

    static requested() {
        const walkParameters = RequestParameterExtractor.extract();
        if (walkParameters.walkDeletions.length > 0) {
            return new DeleteWalksWithIds(walkParameters.walkDeletions);
        }
    }

This means that when the if statement was false the method returned undefined but because I had no type information on the static method, the test was able to run but an undefined Task found it's way into Serenity (perhaps a PR might be worth creating that validates such undefined Tasks and points the developer to their faulty line of code? I'd hate for other people to go through this pain 😭).

So my fixed method now looks like this which always returns a Task:

    static requested(): Task {
        const walkParameters = RequestParameterExtractor.extract();
        if (walkParameters.walkDeletions.length > 0) {
            console.log(`Deleting existing ${walkParameters.walkDeletions.length} walk(s) from site before upload`);
            return new DeleteWalksWithIds(walkParameters.walkDeletions);
        } else {
            return new SilentPerformable();
        }
    }

** SilentPerformable is part of a PR #159 that still awaits your approval 😄.

[jan-molak]

Thanks for the update, @nbarrett! Yes, so it looks like static requested() had an implicit return type of any and perhaps that's why the TS transpiler didn't complain?

Let's discuss the SilentPerformable in #159 and I'll close this ticket unless you feel it should remain open?

[nbarrett]

umm, I could raise a PR following my previous comment?

a PR might be worth creating that validates such undefined Tasks and points the developer to their faulty line of code? I'd hate for other people to go through this pain 😭).