TypeScript Version: 3.6.0-rc

Search Terms:

• diagnostics
• errors
• suggestions
• suggestion diagnostics
• deprecated

Feature request
VS Code recently added special for special rendering of error spans for deprecated symbols:microsoft/vscode#56694 These are rendered as strike out in the editor

We would like the TypeScript server to also generate suggestion diagnostics for uses of deprecated symbols:

/** *@deprecated */functionfoo(){}foo()/* Call to `foo` should rendered with a strike out*/

Proposed API change
This feature is broadly similar to how TypeScript supports rendering unused diagnostics. Unused diagnostics are indicated by areportsUnnecessary field on the diagnostic.

To support deprecated diagnostics as well, we could add a newreportsDeprecated field

[Trace  - 2:56:06 PM] <semantic> Event received: suggestionDiag (0).Data: {    "file": "/Users/matb/projects/san/index.ts",    "diagnostics": [        {            "start": {                "line": 6,                "offset": 10            },            "end": {                "line": 6,                "offset": 13            },            "text": "'foo' is marked deprecated.",            "code": 6133,            "category": "suggestion",            "reportsDeprecated": true        }    ]}

VS Code would provide the support for enabling/disabling deprecated diagnostics; TS Server just needs to return this information to us

Related Issues:

• Add flag to mark TS Server unused variable suggestion diagnostics #23288