Lsp: Any way to raise a warning when calling a deprecated class/method?

[devnix]

Hi! I was wondering if it could be a way to show a warning when calling a deprecated class, method, or whatever deprecable symbol. There is some code that I would write in another way if I had a report on that.

[predragnikolic]

Yes, there is a way :)

This PR https://github.com/sublimelsp/LSP/pull/866 will provide the deprecatedSupport LSP spec.

        /**
         * Client supports the deprecated property on a completion item.
         */
        deprecatedSupport?: boolean;

But because the CompletionItem.deprecated is actually deprecated :)

CompletionItem {
    /**
     * Indicates if this item is deprecated.
     *
     * @deprecated Use `tags` instead if supported.
     */
    deprecated?: boolean;
}

It is still used in servers like metals, rls.
In the future there could be an a follow up PR that would add support for CompletionItemTag :)

[predragnikolic]

There is also depreacted tags for diagnostics.

export interface Diagnostic {
    /**
     * Additional metadata about the diagnostic.
     *
     * @since 3.15.0
     */
    tags?: DiagnosticTag[];
}

/**
 * The diagnostic tags.
 *
 * @since 3.15.0
 */
export namespace DiagnosticTag {
    /**
     * Unused or unnecessary code.
     *
     * Clients are allowed to render diagnostics with this tag faded out instead of having
     * an error squiggle.
     */
    export const Unnecessary: 1 = 1;
    /**
     * Deprecated or obsolete code.
     *
     * Clients are allowed to rendered diagnostics with this tag strike through.
     */
    export const Deprecated: 2 = 2;
}

So we could use that information to show a inline phantom to show a warning sign ⚠ like so:

Note - new ⚠Person()

[rwols]

I'm closing this because it's implemented in ST4 for completion items. For the case of diagnostic tags, continue the conversation in the linked issue above.