Mark deprecated suggestion

[mjbvz]

TypeScript Version: 3.6.0-rc

Search Terms:

• suggest suggestion
• completion completions
• TS Server
• completionInfo

Feature request
VS Code recently added support for rendering suggestions for deprecated symbols with a strikeout: microsoft/vscode#50972

We would like the TS Server to return metadata about completion items that indicates if they are deprecated or not

/**
 * @deprecated
 */
function foo() {}

foo| /* suggestions here should render `foo` with a strike out*/

Proposed API change
In the completionInfo response from the TS Server, for deprecated completions add deprecated to the kindModifiers field:

[Trace  - 2:39:42 PM] <semantic> Response received: completionInfo (373). Request took 151 ms. Success: true 
Result: {
    "isGlobalCompletion": true,
    "isMemberCompletion": false,
    "isNewIdentifierLocation": false,
    "entries": [
        {
            "name": "foo",
            "kind": "var",
            "kindModifiers": "declare deprecated",
            "sortText": "2"
        },
    ...

Related Issues:

• @‌deprecated JSDoc tag #390