support quickinfo and go-to-definition on typeof this (#47085)

* support quickinfo and go-to-definition on `typeof this`

* update baseline

* move code to checkIdentifier

Author: Zzzen

src/compiler/checker.ts

@@ -25107,6 +25107,10 @@ namespace ts {
         }
 
         function checkIdentifier(node: Identifier, checkMode: CheckMode | undefined): Type {
+            if (isThisInTypeQuery(node)) {
+                return checkThisExpression(node);
+            }
+
             const symbol = getResolvedSymbol(node);
             if (symbol === unknownSymbol) {
                 return errorType;
@@ -41245,7 +41249,10 @@ namespace ts {
                 case SyntaxKind.PrivateIdentifier:
                 case SyntaxKind.PropertyAccessExpression:
                 case SyntaxKind.QualifiedName:
-                    return getSymbolOfNameOrPropertyAccessExpression(node as EntityName | PrivateIdentifier | PropertyAccessExpression);
+                    if (!isThisInTypeQuery(node)) {
+                        return getSymbolOfNameOrPropertyAccessExpression(node as EntityName | PrivateIdentifier | PropertyAccessExpression);
+                    }
+                    // falls through
 
                 case SyntaxKind.ThisKeyword:
                     const container = getThisContainer(node, /*includeArrowFunctions*/ false);

src/services/symbolDisplay.ts

@@ -41,7 +41,7 @@ namespace ts.SymbolDisplay {
         if (typeChecker.isArgumentsSymbol(symbol)) {
             return ScriptElementKind.localVariableElement;
         }
-        if (location.kind === SyntaxKind.ThisKeyword && isExpression(location)) {
+        if (location.kind === SyntaxKind.ThisKeyword && isExpression(location) || isThisInTypeQuery(location)) {
             return ScriptElementKind.parameterElement;
         }
         const flags = getCombinedLocalAndExportSymbolFlags(symbol);
@@ -143,7 +143,7 @@ namespace ts.SymbolDisplay {
         const symbolFlags = getCombinedLocalAndExportSymbolFlags(symbol);
         let symbolKind = semanticMeaning & SemanticMeaning.Value ? getSymbolKindOfConstructorPropertyMethodAccessorFunctionOrVar(typeChecker, symbol, location) : ScriptElementKind.unknown;
         let hasAddedSymbolInfo = false;
-        const isThisExpression = location.kind === SyntaxKind.ThisKeyword && isInExpressionContext(location);
+        const isThisExpression = location.kind === SyntaxKind.ThisKeyword && isInExpressionContext(location) || isThisInTypeQuery(location);
         let type: Type | undefined;
         let printer: Printer;
         let documentationFromAlias: SymbolDisplayPart[] | undefined;

tests/baselines/reference/initializerReferencingConstructorLocals.symbols

@@ -16,6 +16,7 @@ class C {
 
     d: typeof this.z; // error
 >d : Symbol(C.d, Decl(initializerReferencingConstructorLocals.ts, 5, 15))
+>this : Symbol(C, Decl(initializerReferencingConstructorLocals.ts, 0, 0))
 
     constructor(x) {
 >x : Symbol(x, Decl(initializerReferencingConstructorLocals.ts, 7, 16))
@@ -40,6 +41,7 @@ class D<T> {
 
     d: typeof this.z; // error
 >d : Symbol(D.d, Decl(initializerReferencingConstructorLocals.ts, 15, 15))
+>this : Symbol(D, Decl(initializerReferencingConstructorLocals.ts, 10, 1))
 
     constructor(x: T) {
 >x : Symbol(x, Decl(initializerReferencingConstructorLocals.ts, 17, 16))

tests/baselines/reference/initializerReferencingConstructorLocals.types

@@ -21,7 +21,7 @@ class C {
     d: typeof this.z; // error
 >d : any
 >this.z : any
->this : any
+>this : this
 >z : any
 
     constructor(x) {
@@ -54,7 +54,7 @@ class D<T> {
     d: typeof this.z; // error
 >d : any
 >this.z : any
->this : any
+>this : this
 >z : any
 
     constructor(x: T) {

tests/baselines/reference/initializerReferencingConstructorParameters.symbols

@@ -39,6 +39,7 @@ class E {
     b: typeof this.x; // ok
 >b : Symbol(E.b, Decl(initializerReferencingConstructorParameters.ts, 15, 15))
 >this.x : Symbol(E.x, Decl(initializerReferencingConstructorParameters.ts, 17, 16))
+>this : Symbol(E, Decl(initializerReferencingConstructorParameters.ts, 12, 1))
 >x : Symbol(E.x, Decl(initializerReferencingConstructorParameters.ts, 17, 16))
 
     constructor(public x) { }

tests/baselines/reference/initializerReferencingConstructorParameters.types

@@ -43,7 +43,7 @@ class E {
     b: typeof this.x; // ok
 >b : any
 >this.x : any
->this : any
+>this : this
 >x : any
 
     constructor(public x) { }