Tooltip drill down

[mjbvz]

From @unional on January 4, 2017 2:14

• VSCode Version: 1.8.0
  Steps to Reproduce:

interface FooOption {
  /**
   * Doing boo stuff
   */
  boo(x: number): boolean
}

function foo(option: FooOption) {

}

foo({
  boo()
})

Currently, autocomplete is doing a better job than the tooltip. When you type boo, autocomplete gets the definition of boo and display it. But once you type (, it falls back to the tooltips and only show the tooltip of foo(...) instead.

It would be nice to have the tooltips shows the info for boo(). 🌷

Copied from original issue: microsoft/vscode#18070

[mjbvz]

From @sandy081 on January 4, 2017 9:31

@unional This is happening because you are not accessing function boo using object of type FooOption. If you does that tool tip provides you proper information.

[mjbvz]

From @unional on January 4, 2017 18:54

Yes, I understand it is not:

let b: FooOption;
b.boo(
      ^ cursor here

However it is very common practice in JS to do this kind of option bag, and it would be better to drill down and display the same information in this scenario.

[mjbvz]

From @sandy081 on January 5, 2017 13:13

I see. Reopening and assigning to correct owner to provide correct feedback on this.

[mjbvz]

After investingating, it seems like TS is returning the wrong signigutreHelp response in this case. For the code:

interface FooOption {
  /**
   * Doing boo stuff
   */
  boo(x: number): boolean
}

function foo(option: FooOption) {

}

foo({
boo| {
  return false;
}
})

By typing ( as the location of the | character on line 13, we see the following:

Trace - 2:18:02 PM] Sending request: signatureHelp (395). Response expected: yes. Current queue length: 0
Arguments: {
    "file": "/Users/matb/projects/sand/bla.ts",
    "line": 13,
    "offset": 5
}
[Trace - 2:18:02 PM] Response received: signatureHelp (395). Request took 2 ms. Success: true 
Result: {
    "items": [
        {
            "isVariadic": false,
            "prefixDisplayParts": [
                {
                    "text": "foo",
                    "kind": "functionName"
                },
                {
                    "text": "(",
                    "kind": "punctuation"
                }
            ],
            "suffixDisplayParts": [
                {
                    "text": ")",
                    "kind": "punctuation"
                },
                {
                    "text": ":",
                    "kind": "punctuation"
                },
                {
                    "text": " ",
                    "kind": "space"
                },
                {
                    "text": "void",
                    "kind": "keyword"
                }
            ],
            "separatorDisplayParts": [
                {
                    "text": ",",
                    "kind": "punctuation"
                },
                {
                    "text": " ",
                    "kind": "space"
                }
            ],
            "parameters": [
                {
                    "name": "option",
                    "documentation": [],
                    "displayParts": [
                        {
                            "text": "option",
                            "kind": "parameterName"
                        },
                        {
                            "text": ":",
                            "kind": "punctuation"
                        },
                        {
                            "text": " ",
                            "kind": "space"
                        },
                        {
                            "text": "FooOption",
                            "kind": "interfaceName"
                        }
                    ],
                    "isOptional": false
                }
            ],
            "documentation": [],
            "tags": []
        }
    ],
    "applicableSpan": {
        "start": {
            "line": 12,
            "offset": 5
        },
        "end": {
            "line": 16,
            "offset": 2
        }
    },
    "selectedItemIndex": 0,
    "argumentIndex": 0,
    "argumentCount": 1
}

The requested signatureHelp position is within the boo function at this point, but we still get the result for foo