Fix/issue-575: Handling no experimentId in mark api call

[ppratikcr7]

No description provided.

[zackcl]

Just wondering if it's a better solution than let selectedExperimentDP = experimentDecisionPoint.filter( dp => dp.experiment.id === experimentId || experimentId === ''); which was what I did to not see the error.

[ppratikcr7]

Both will give same result, but in your case it will check again for the dp which already we can filter out before as I have done and we just return the monitored dp.

[zackcl]

Got it, thank you!

[danoswaltCL]

If this is really all that's needed, then the tertiary condition to set the empty string really isn't necessary, we can simplify a little more:

if (!experimentId) {
   if (filteredExperiments.length > 1) {
      const random = seedrandom(userId)();
      experimentId = filteredExperiments[Math.floor(random * experiments.length)].id;
   } else {
      experimentId = filteredExperiments[0]?.id; // <--- no need for extra conditional here, let it be undefined, no need for empty string
   }
}

and then you can do this so that it's not just an empty string it's checking, it's checking all falsey values that would potentially get the same runtime error:

if (experimentDecisionPoint.length && experimentId) {

which also catches any weird edge-case where experimentId is somehow falsey for any other reason (such as if somehow experimentId = filteredExperiments[Math.floor(random * experiments.length)].id; returns undefined or NaN, which could technically happen I think if experiments.length is undefined or an unexpected number, or if that id is messed up. These aren't important scenarios, but you never know.

[ppratikcr7]

If this is really all that's needed, then the tertiary condition to set the empty string really isn't necessary, we can simplify a little more:

if (!experimentId) {
   if (filteredExperiments.length > 1) {
      const random = seedrandom(userId)();
      experimentId = filteredExperiments[Math.floor(random * experiments.length)].id;
   } else {
      experimentId = filteredExperiments[0]?.id; // <--- no need for extra conditional here, let it be undefined, no need for empty string
   }
}

and then you can do this so that it's not just an empty string it's checking, it's checking all falsey values that would potentially get the same runtime error:

if (experimentDecisionPoint.length && experimentId) {

which also catches any weird edge-case where experimentId is somehow falsey for any other reason (such as if somehow experimentId = filteredExperiments[Math.floor(random * experiments.length)].id; returns undefined or NaN, which could technically happen I think if experiments.length is undefined or an unexpected number, or if that id is messed up. These aren't important scenarios, but you never know.

Okay, I will update the PR. Thanks :)