Report error for duplicate @type declaration in @typedef

TypeScript Version: master

Code

/**
 * @typedef Name
 * @type {string}
 * @type {Oops} - this is dropped and we stop parsing the @typedef
 */

Expected behavior:

Error.

Actual behavior:

No error.

[noamyogev84]

Hi @mhegazy can I try that one?

[sandersn]

@noamyogev84 Go for it!

[noamyogev84]

Thanks @sandersn. can you please share some code pointers?

[sandersn]

You'll want to start in parseTypedefTag in parser.ts. There is a section of code that checks for the child @type inside @typedef:

while (child = tryParse(() => parseChildPropertyTag(indent))) {
    // ...
    if (child.kind === SyntaxKind.JSDocTypeTag) {
        if (childTypeTag) {
            break;
        }
        else {
            childTypeTag = child;
        }
    }
    // ...
}

As you can see, in case of duplicate @type tags, the code just breaks out of the loop with no error. Add a call to parseErrorAtCurrentToken before breaking out of the loop. DiagnosticMessages.Unexpected_token is probably good enough for the message, but you can add a new one in diagnosticMessages.json if you want. Maybe "Unexpected tag '{0}'." or "Duplicate tag '{0}'."

For adding tests, follow the directions in CONTRIBUTING, except that you should add your test in ts/tests/cases/conformance/jsdoc, and you will need to explicitly allow JS at the top:

// @allowJS: true
// @checkJS: true
// @noEmit: true
// @Filename: bug17442.js
// ... actual test goes here ...

@DanielRosenwasser any opinions on what the error message should be?

[noamyogev84]

Great I'm on it.

[noamyogev84]

Hi @sandersn,
Following your directions does not produce the wanted result, or maybe i'm missing something. (No error message is outputted by the compiler)
I'm debugging tsc.js and it seems like parseErrorAtCurrentToken does not affect the rest of the method.

"Planting" an arbitrary syntax error in the above example does produce error, but I still can't figure out where it's being handled. Do you have any idea what's missing?