Fix default property assigned prototype

src/compiler/checker.ts

@@ -507,6 +507,7 @@ namespace ts {
             },
             getAugmentedPropertiesOfType,
             getRootSymbols,
+            getSymbolOfExpando,
             getContextualType: (nodeIn: Expression, contextFlags?: ContextFlags) => {
                 const node = getParseTreeNode(nodeIn, isExpression);
                 if (!node) {
@@ -8728,9 +8729,9 @@ namespace ts {
             let links = getSymbolLinks(symbol);
             const originalLinks = links;
             if (!links.type) {
-                const jsDeclaration = symbol.valueDeclaration && getDeclarationOfExpando(symbol.valueDeclaration);
-                if (jsDeclaration) {
-                    const merged = mergeJSSymbols(symbol, getSymbolOfNode(jsDeclaration));
+                const expando = symbol.valueDeclaration && getSymbolOfExpando(symbol.valueDeclaration, /*allowDeclaration*/ false);
+                if (expando) {
+                    const merged = mergeJSSymbols(symbol, expando);
                     if (merged) {
                         // note:we overwrite links because we just cloned the symbol
                         symbol = links = merged;
@@ -24828,7 +24829,7 @@ namespace ts {
                     const exprType = checkJsxAttribute(attributeDecl, checkMode);
                     objectFlags |= getObjectFlags(exprType) & ObjectFlags.PropagatingFlags;
 
-                    const attributeSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient | member.flags, member.escapedName);
+                    const attributeSymbol = createSymbol(SymbolFlags.Property | member.flags, member.escapedName);
                     attributeSymbol.declarations = member.declarations;
                     attributeSymbol.parent = member.parent;
                     if (member.valueDeclaration) {
@@ -24887,7 +24888,7 @@ namespace ts {
                     const contextualType = getApparentTypeOfContextualType(openingLikeElement.attributes);
                     const childrenContextualType = contextualType && getTypeOfPropertyOfContextualType(contextualType, jsxChildrenPropertyName);
                     // If there are children in the body of JSX element, create dummy attribute "children" with the union of children types so that it will pass the attribute checking process
-                    const childrenPropSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, jsxChildrenPropertyName);
+                    const childrenPropSymbol = createSymbol(SymbolFlags.Property, jsxChildrenPropertyName);
                     childrenPropSymbol.type = childrenTypes.length === 1 ? childrenTypes[0] :
                         childrenContextualType && forEachType(childrenContextualType, isTupleLikeType) ? createTupleType(childrenTypes) :
                         createArrayType(getUnionType(childrenTypes));
@@ -28076,15 +28077,59 @@ namespace ts {
         }
 
         function getAssignedClassSymbol(decl: Declaration): Symbol | undefined {
-            const assignmentSymbol = decl && decl.parent &&
-                (isFunctionDeclaration(decl) && getSymbolOfNode(decl) ||
-                 isBinaryExpression(decl.parent) && getSymbolOfNode(decl.parent.left) ||
-                 isVariableDeclaration(decl.parent) && getSymbolOfNode(decl.parent));
-            const prototype = assignmentSymbol && assignmentSymbol.exports && assignmentSymbol.exports.get("prototype" as __String);
-            const init = prototype && prototype.valueDeclaration && getAssignedJSPrototype(prototype.valueDeclaration);
+            const assignmentSymbol = decl && getSymbolOfExpando(decl, /*allowDeclaration*/ true);
+            const prototype = assignmentSymbol?.exports?.get("prototype" as __String);
+            const init = prototype?.valueDeclaration && getAssignedJSPrototype(prototype.valueDeclaration);
             return init ? getSymbolOfNode(init) : undefined;
         }
 
+        function getSymbolOfExpando(node: Node, allowDeclaration: boolean): Symbol | undefined {
+            if (!node.parent) {
+                return undefined;
+            }
+            let name: Expression | BindingName | undefined;
+            let decl: Node | undefined;
+            if (isVariableDeclaration(node.parent) && node.parent.initializer === node) {
+                if (!isInJSFile(node) && !isVarConst(node.parent)) {
+                    return undefined;
+                }
+                name = node.parent.name;
+                decl = node.parent;
+            }
+            else if (isBinaryExpression(node.parent)) {
+                const parentNode = node.parent;
+                const parentNodeOperator = node.parent.operatorToken.kind;
+                if (parentNodeOperator === SyntaxKind.EqualsToken && (allowDeclaration || parentNode.right === node)) {
+                    name = parentNode.left;
+                    decl = name;
+                }
+                else if (parentNodeOperator === SyntaxKind.BarBarToken || parentNodeOperator === SyntaxKind.QuestionQuestionToken) {
+                    if (isVariableDeclaration(parentNode.parent) && parentNode.parent.initializer === parentNode) {
+                        name = parentNode.parent.name;
+                        decl = parentNode.parent;
+                    }
+                    else if (isBinaryExpression(parentNode.parent) && parentNode.parent.operatorToken.kind === SyntaxKind.EqualsToken && (allowDeclaration || parentNode.parent.right === parentNode)) {
+                        name = parentNode.parent.left;
+                        decl = name;
+                    }
+
+                    if (!name || !isBindableStaticNameExpression(name) || !isSameEntityName(name, parentNode.left)) {
+                        return undefined;
+                    }
+                }
+            }
+            else if (allowDeclaration && isFunctionDeclaration(node)) {
+                name = node.name;
+                decl = node;
+            }
+
+            if (!decl || !name || (!allowDeclaration && !getExpandoInitializer(node, isPrototypeAccess(name)))) {
+                return undefined;
+            }
+            return getSymbolOfNode(decl);
+        }
+
+
         function getAssignedJSPrototype(node: Node) {
             if (!node.parent) {
                 return false;
@@ -28161,14 +28206,11 @@ namespace ts {
             }
 
             if (isInJSFile(node)) {
-                const decl = getDeclarationOfExpando(node);
-                if (decl) {
-                    const jsSymbol = getSymbolOfNode(decl);
-                    if (jsSymbol?.exports?.size) {
-                        const jsAssignmentType = createAnonymousType(jsSymbol, jsSymbol.exports, emptyArray, emptyArray, undefined, undefined);
-                        jsAssignmentType.objectFlags |= ObjectFlags.JSLiteral;
-                        return getIntersectionType([returnType, jsAssignmentType]);
-                    }
+                const jsSymbol = getSymbolOfExpando(node, /*allowDeclaration*/ false);
+                if (jsSymbol?.exports?.size) {
+                    const jsAssignmentType = createAnonymousType(jsSymbol, jsSymbol.exports, emptyArray, emptyArray, undefined, undefined);
+                    jsAssignmentType.objectFlags |= ObjectFlags.JSLiteral;
+                    return getIntersectionType([returnType, jsAssignmentType]);
                 }
             }
 

src/compiler/types.ts

@@ -4004,6 +4004,7 @@ namespace ts {
         getAugmentedPropertiesOfType(type: Type): Symbol[];
 
         getRootSymbols(symbol: Symbol): readonly Symbol[];
+        getSymbolOfExpando(node: Node, allowDeclaration: boolean): Symbol | undefined;
         getContextualType(node: Expression): Type | undefined;
         /* @internal */ getContextualType(node: Expression, contextFlags?: ContextFlags): Type | undefined; // eslint-disable-line @typescript-eslint/unified-signatures
         /* @internal */ getContextualTypeForObjectLiteralElement(element: ObjectLiteralElementLike): Type | undefined;

src/compiler/utilities.ts

@@ -1937,48 +1937,6 @@ namespace ts {
         return getSourceTextOfNodeFromSourceFile(sourceFile, str).charCodeAt(0) === CharacterCodes.doubleQuote;
     }
 
-    export function getDeclarationOfExpando(node: Node): Node | undefined {
-        if (!node.parent) {
-            return undefined;
-        }
-        let name: Expression | BindingName | undefined;
-        let decl: Node | undefined;
-        if (isVariableDeclaration(node.parent) && node.parent.initializer === node) {
-            if (!isInJSFile(node) && !isVarConst(node.parent)) {
-                return undefined;
-            }
-            name = node.parent.name;
-            decl = node.parent;
-        }
-        else if (isBinaryExpression(node.parent)) {
-            const parentNode = node.parent;
-            const parentNodeOperator = node.parent.operatorToken.kind;
-            if (parentNodeOperator === SyntaxKind.EqualsToken && parentNode.right === node) {
-                name = parentNode.left;
-                decl = name;
-            }
-            else if (parentNodeOperator === SyntaxKind.BarBarToken || parentNodeOperator === SyntaxKind.QuestionQuestionToken) {
-                if (isVariableDeclaration(parentNode.parent) && parentNode.parent.initializer === parentNode) {
-                    name = parentNode.parent.name;
-                    decl = parentNode.parent;
-                }
-                else if (isBinaryExpression(parentNode.parent) && parentNode.parent.operatorToken.kind === SyntaxKind.EqualsToken && parentNode.parent.right === parentNode) {
-                    name = parentNode.parent.left;
-                    decl = name;
-                }
-
-                if (!name || !isBindableStaticNameExpression(name) || !isSameEntityName(name, parentNode.left)) {
-                    return undefined;
-                }
-            }
-        }
-
-        if (!name || !getExpandoInitializer(node, isPrototypeAccess(name))) {
-            return undefined;
-        }
-        return decl;
-    }
-
     export function isAssignmentDeclaration(decl: Declaration) {
         return isBinaryExpression(decl) || isAccessExpression(decl) || isIdentifier(decl) || isCallExpression(decl);
     }
@@ -2098,7 +2056,7 @@ namespace ts {
      * var min = window.min || {}
      * my.app = self.my.app || class { }
      */
-    function isSameEntityName(name: Expression, initializer: Expression): boolean {
+    export function isSameEntityName(name: Expression, initializer: Expression): boolean {
         if (isPropertyNameLiteral(name) && isPropertyNameLiteral(initializer)) {
             return getTextOfIdentifierOrLiteral(name) === getTextOfIdentifierOrLiteral(initializer);
         }

src/services/suggestionDiagnostics.ts

@@ -37,7 +37,7 @@ namespace ts {
 
         function check(node: Node) {
             if (isJsFile) {
-                if (canBeConvertedToClass(node)) {
+                if (canBeConvertedToClass(node, checker)) {
                     diags.push(createDiagnosticForNode(isVariableDeclaration(node.parent) ? node.parent.name : node, Diagnostics.This_constructor_function_may_be_converted_to_a_class_declaration));
                 }
             }
@@ -190,14 +190,13 @@ namespace ts {
         return `${exp.pos.toString()}:${exp.end.toString()}`;
     }
 
-    function canBeConvertedToClass(node: Node): boolean {
+    function canBeConvertedToClass(node: Node, checker: TypeChecker): boolean {
         if (node.kind === SyntaxKind.FunctionExpression) {
             if (isVariableDeclaration(node.parent) && node.symbol.members?.size) {
                 return true;
             }
 
-            const decl = getDeclarationOfExpando(node);
-            const symbol = decl?.symbol;
+            const symbol = checker.getSymbolOfExpando(node, /*allowDeclaration*/ false);
             return !!(symbol && (symbol.exports?.size || symbol.members?.size));
         }
 

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -2207,6 +2207,7 @@ declare namespace ts {
         getFullyQualifiedName(symbol: Symbol): string;
         getAugmentedPropertiesOfType(type: Type): Symbol[];
         getRootSymbols(symbol: Symbol): readonly Symbol[];
+        getSymbolOfExpando(node: Node, allowDeclaration: boolean): Symbol | undefined;
         getContextualType(node: Expression): Type | undefined;
         /**
          * returns unknownSignature in the case of an error.

tests/baselines/reference/api/typescript.d.ts

@@ -2207,6 +2207,7 @@ declare namespace ts {
         getFullyQualifiedName(symbol: Symbol): string;
         getAugmentedPropertiesOfType(type: Type): Symbol[];
         getRootSymbols(symbol: Symbol): readonly Symbol[];
+        getSymbolOfExpando(node: Node, allowDeclaration: boolean): Symbol | undefined;
         getContextualType(node: Expression): Type | undefined;
         /**
          * returns unknownSignature in the case of an error.

tests/baselines/reference/defaultPropertyAssignedClassWithPrototype.symbols

@@ -0,0 +1,33 @@
+=== tests/cases/conformance/salsa/bug39167.js ===
+var test = {};
+>test : Symbol(test, Decl(bug39167.js, 0, 3), Decl(bug39167.js, 0, 14), Decl(bug39167.js, 2, 18))
+
+test.K = test.K ||
+>test.K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>test : Symbol(test, Decl(bug39167.js, 0, 3), Decl(bug39167.js, 0, 14), Decl(bug39167.js, 2, 18))
+>K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>test.K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>test : Symbol(test, Decl(bug39167.js, 0, 3), Decl(bug39167.js, 0, 14), Decl(bug39167.js, 2, 18))
+>K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+
+    function () {}
+
+test.K.prototype = {
+>test.K.prototype : Symbol(test.K.prototype, Decl(bug39167.js, 2, 18))
+>test.K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>test : Symbol(test, Decl(bug39167.js, 0, 3), Decl(bug39167.js, 0, 14), Decl(bug39167.js, 2, 18))
+>K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>prototype : Symbol(test.K.prototype, Decl(bug39167.js, 2, 18))
+
+    add() {}
+>add : Symbol(add, Decl(bug39167.js, 4, 20))
+
+};
+
+new test.K().add;
+>new test.K().add : Symbol(add, Decl(bug39167.js, 4, 20))
+>test.K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>test : Symbol(test, Decl(bug39167.js, 0, 3), Decl(bug39167.js, 0, 14), Decl(bug39167.js, 2, 18))
+>K : Symbol(test.K, Decl(bug39167.js, 0, 14), Decl(bug39167.js, 4, 5))
+>add : Symbol(add, Decl(bug39167.js, 4, 20))
+

tests/baselines/reference/defaultPropertyAssignedClassWithPrototype.types

@@ -0,0 +1,40 @@
+=== tests/cases/conformance/salsa/bug39167.js ===
+var test = {};
+>test : typeof test
+>{} : {}
+
+test.K = test.K ||
+>test.K = test.K ||    function () {} : typeof K
+>test.K : typeof K
+>test : typeof test
+>K : typeof K
+>test.K ||    function () {} : typeof K
+>test.K : typeof K
+>test : typeof test
+>K : typeof K
+
+    function () {}
+>function () {} : typeof K
+
+test.K.prototype = {
+>test.K.prototype = {    add() {}} : { add(): void; }
+>test.K.prototype : { add(): void; }
+>test.K : typeof K
+>test : typeof test
+>K : typeof K
+>prototype : { add(): void; }
+>{    add() {}} : { add(): void; }
+
+    add() {}
+>add : () => void
+
+};
+
+new test.K().add;
+>new test.K().add : () => void
+>new test.K() : K
+>test.K : typeof K
+>test : typeof test
+>K : typeof K
+>add : () => void
+

tests/cases/conformance/salsa/defaultPropertyAssignedClassWithPrototype.ts

@@ -0,0 +1,13 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @Filename: bug39167.js
+var test = {};
+test.K = test.K ||
+    function () {}
+
+test.K.prototype = {
+    add() {}
+};
+
+new test.K().add;