Merge pull request microsoft#15677 from Microsoft/find-all-refs-mapped-type

findAllReferences: Don't need to check for `symbol.declarations`

Author: Andy

src/services/findAllReferences.ts

@@ -108,10 +108,6 @@ namespace ts.FindAllReferences {
             switch (def.type) {
                 case "symbol": {
                     const { symbol, node } = def;
-                    const declarations = symbol.declarations;
-                    if (!declarations || declarations.length === 0) {
-                        return undefined;
-                    }
                     const { displayParts, kind } = getDefinitionKindAndDisplayParts(symbol, node, checker);
                     const name = displayParts.map(p => p.text).join("");
                     return { node, name, kind, displayParts };
@@ -285,11 +281,6 @@ namespace ts.FindAllReferences.Core {
             return undefined;
         }
 
-        // The symbol was an internal symbol and does not have a declaration e.g. undefined symbol
-        if (!symbol.declarations || !symbol.declarations.length) {
-            return undefined;
-        }
-
         return getReferencedSymbolsForSymbol(symbol, node, sourceFiles, checker, cancellationToken, options);
     }
 

tests/cases/fourslash/findAllRefsMappedType.ts

@@ -0,0 +1,15 @@
+/// <reference path='fourslash.ts'/>
+
+////interface T { [|{| "isWriteAccess": true, "isDefinition": true |}a|]: number; }
+////type U = { readonly [K in keyof T]?: string };
+////declare const t: T;
+////t.[|a|];
+////declare const u: U;
+////u.[|a|];
+
+const ranges = test.ranges();
+const [r0, r1, r2] = ranges;
+verify.referenceGroups([r0, r1], [{ definition: "(property) T.a: number", ranges }]);
+verify.referenceGroups(r2, [
+    { definition: "(property) T.a: number", ranges: [r0, r1] },
+    { definition: "(property) a: string", ranges: [r2] }]);