fix(193523): JSDoc optional parameters don't display in functions

[perplexyves]

Hello. This PR is a fix to #193523, which was labelled with both help-wanted and bug labels.

Useful summary of the issue:

• First, go to settings.json and add these 2 config lines:

"editor.suggest.preview": true,
"javascript.suggest.completeFunctionCalls": true,

• Then, in a JS file type the following:

/**
 * @param {string} one hi.
 * @param {number} two howdy.
 * @param {string} [three] hello.
 */
function test(one, two, three) { }

• Now, when you try to invoke the function test, you should notice that in the autocompletion preview the optional params have been omitted:

  

After applying the fix (based on @RyanCavanaugh advice), the problem is solved.

[perplexyves]

Also I am ready to assist with any unit test to cover this case.

[akobrin]

I am unfamiliar with this whole review process. Is the bottom line that the fix will be included in a VS Code update in the future? Thank you

[mjbvz]

We still want to hide optional parameters at the end of the list. Otherwise some library functions will generation an overwhelming number of parameters that you don't care about

#193523 is specifically about when the optional parameter appears between two non-optional params. Let's focus on that case

Also make sure to add tests. These are defined in functionCallSnippet.test.ts

[perplexyves]

@microsoft-github-policy-service agree

[perplexyves]

I've added the requested changes @mjbvz. Ready to assist if needed.

[perplexyves]

Hello Matt. Just fixed the integration tests. Can you please review once available? @mjbvz

[mjbvz]

Thanks!

[perplexyves]

Pleasure!