quickInfo: Get JSDoc tags from aliased symbol (#23526)

* quickInfo: Get JSDoc tags from aliased symbol

* Add test with existing tags

src/services/symbolDisplay.ts

@@ -134,6 +134,7 @@ namespace ts.SymbolDisplay {
         let type: Type;
         let printer: Printer;
         let documentationFromAlias: SymbolDisplayPart[];
+        let tagsFromAlias: JSDocTagInfo[];
 
         // Class at constructor site need to be shown as constructor apart from property,method, vars
         if (symbolKind !== ScriptElementKind.unknown || symbolFlags & SymbolFlags.Class || symbolFlags & SymbolFlags.Alias) {
@@ -396,6 +397,7 @@ namespace ts.SymbolDisplay {
                         displayParts.push(...resolvedInfo.displayParts);
                         displayParts.push(lineBreakPart());
                         documentationFromAlias = resolvedInfo.documentation;
+                        tagsFromAlias = resolvedInfo.tags;
                     }
                 }
             }
@@ -521,6 +523,9 @@ namespace ts.SymbolDisplay {
         if (documentation.length === 0 && documentationFromAlias) {
             documentation = documentationFromAlias;
         }
+        if (tags.length === 0 && tagsFromAlias) {
+            tags = tagsFromAlias;
+        }
 
         return { displayParts, documentation, symbolKind, tags };
 

tests/cases/fourslash/fourslash.ts

@@ -338,7 +338,7 @@ declare namespace FourSlashInterface {
         verifyQuickInfoDisplayParts(kind: string, kindModifiers: string, textSpan: {
             start: number;
             length: number;
-        }, displayParts: ts.SymbolDisplayPart[], documentation: ts.SymbolDisplayPart[], tags: ts.JSDocTagInfo[]): void;
+        }, displayParts: ts.SymbolDisplayPart[], documentation: ts.SymbolDisplayPart[], tags: { name: string, text?: string }[]): void;
         getSyntacticDiagnostics(expected: ReadonlyArray<Diagnostic>): void;
         getSemanticDiagnostics(expected: ReadonlyArray<Diagnostic>): void;
         getSuggestionDiagnostics(expected: ReadonlyArray<Diagnostic>): void;

tests/cases/fourslash/quickInfoAlias.ts

@@ -0,0 +1,51 @@
+/// <reference path='fourslash.ts'/>
+
+// @Filename: /a.ts
+/////**
+//// * Doc
+//// * @tag Tag text
+//// */
+////export const x = 0;
+
+// @Filename: /b.ts
+////import { x } from "./a";
+////x/*b*/;
+
+// @Filename: /c.ts
+/////**
+//// * Doc 2
+//// * @tag Tag text 2
+//// */
+////import {
+////    /**
+////     * Doc 3
+////     * @tag Tag text 3
+////     */
+////    x
+////} from "./a";
+////x/*c*/;
+
+goTo.eachMarker((_, index) => {
+    verify.verifyQuickInfoDisplayParts(
+        "alias",
+        "",
+        { start: index === 0 ? 25 : 117, length: 1 },
+        [
+            { text:"(",kind:"punctuation" },
+            { text:"alias",kind:"text" },
+            { text:")",kind:"punctuation" },
+            { text:" ",kind:"space" },
+            { text:"const",kind:"keyword" },
+            { text:" ",kind:"space" },
+            { text:"x",kind:"aliasName" },
+            { text:":",kind:"punctuation" },
+            { text:" ",kind:"space" },
+            { text:"0",kind:"stringLiteral" },
+            { text:"\n",kind:"lineBreak" },
+            { text:"import",kind:"keyword" },
+            { text:" ",kind:"space" },
+            { text:"x",kind:"aliasName" },
+        ],
+        [{ text: "Doc", kind: "text" }],
+        [{ name: "tag", text: "Tag text" }]);
+});