Handle imports and exports in 'convert parameters to destructured object'

src/compiler/utilities.ts

@@ -1330,6 +1330,10 @@ namespace ts {
         return findAncestor(node.parent, isFunctionLike);
     }
 
+    export function getContainingFunctionDeclaration(node: Node): FunctionLikeDeclaration | undefined {
+        return findAncestor(node.parent, isFunctionLikeDeclaration);
+    }
+
     export function getContainingClass(node: Node): ClassLikeDeclaration | undefined {
         return findAncestor(node.parent, isClassLike);
     }

src/services/refactors/convertParamsToDestructuredObject.ts

@@ -90,8 +90,8 @@ namespace ts.refactor.convertParamsToDestructuredObject {
         function groupReferences(referenceEntries: ReadonlyArray<FindAllReferences.Entry>): GroupedReferences {
             const classReferences: ClassReferences = { accessExpressions: [], typeUsages: [] };
             const groupedReferences: GroupedReferences = { functionCalls: [], declarations: [], classReferences, valid: true };
-            const functionSymbols = map(functionNames, checker.getSymbolAtLocation);
-            const classSymbols = map(classNames, checker.getSymbolAtLocation);
+            const functionSymbols = map(functionNames, getSymbolTargetAtLocation);
+            const classSymbols = map(classNames, getSymbolTargetAtLocation);
             const isConstructor = isConstructorDeclaration(functionDeclaration);
 
             for (const entry of referenceEntries) {
@@ -111,7 +111,11 @@ namespace ts.refactor.convertParamsToDestructuredObject {
                 So we need to add a special case for this because when calling a constructor of a class through one of its subclasses,
                 the symbols are going to be different.
                 */
-                if (contains(functionSymbols, checker.getSymbolAtLocation(entry.node), symbolComparer) || isNewExpressionTarget(entry.node)) {
+                if (contains(functionSymbols, getSymbolTargetAtLocation(entry.node)) || isNewExpressionTarget(entry.node)) {
+                    const importOrExportReference = entryToImportOrExport(entry);
+                    if (importOrExportReference) {
+                        continue;
+                    }
                     const decl = entryToDeclaration(entry);
                     if (decl) {
                         groupedReferences.declarations.push(decl);
@@ -125,7 +129,12 @@ namespace ts.refactor.convertParamsToDestructuredObject {
                     }
                 }
                 // if the refactored function is a constructor, we must also check if the references to its class are valid
-                if (isConstructor && contains(classSymbols, checker.getSymbolAtLocation(entry.node), symbolComparer)) {
+                if (isConstructor && contains(classSymbols, getSymbolTargetAtLocation(entry.node))) {
+                    const importOrExportReference = entryToImportOrExport(entry);
+                    if (importOrExportReference) {
+                        continue;
+                    }
+
                     const decl = entryToDeclaration(entry);
                     if (decl) {
                         groupedReferences.declarations.push(decl);
@@ -153,10 +162,27 @@ namespace ts.refactor.convertParamsToDestructuredObject {
 
             return groupedReferences;
         }
+
+        function getSymbolTargetAtLocation(node: Node) {
+            const symbol = checker.getSymbolAtLocation(node);
+            return symbol && getSymbolTarget(symbol, checker);
+        }
     }
 
-    function symbolComparer(a: Symbol, b: Symbol): boolean {
-        return getSymbolTarget(a) === getSymbolTarget(b);
+    function entryToImportOrExport(entry: FindAllReferences.NodeEntry): Node | undefined {
+        const node = entry.node;
+
+        if (isImportSpecifier(node.parent)
+            || isImportClause(node.parent)
+            || isImportEqualsDeclaration(node.parent)
+            || isNamespaceImport(node.parent)) {
+            return node;
+        }
+
+        if (isExportSpecifier(node.parent) || isExportAssignment(node.parent)) {
+            return node;
+        }
+        return undefined;
     }
 
     function entryToDeclaration(entry: FindAllReferences.NodeEntry): Node | undefined {
@@ -171,37 +197,31 @@ namespace ts.refactor.convertParamsToDestructuredObject {
             const functionReference = entry.node;
             const parent = functionReference.parent;
             switch (parent.kind) {
-                // Function call (foo(...) or super(...))
+                // foo(...) or super(...) or new Foo(...)
                 case SyntaxKind.CallExpression:
-                    const callExpression = tryCast(parent, isCallExpression);
-                    if (callExpression && callExpression.expression === functionReference) {
-                        return callExpression;
-                    }
-                    break;
-                // Constructor call (new Foo(...))
                 case SyntaxKind.NewExpression:
-                    const newExpression = tryCast(parent, isNewExpression);
-                    if (newExpression && newExpression.expression === functionReference) {
-                        return newExpression;
+                    const callOrNewExpression = tryCast(parent, isCallOrNewExpression);
+                    if (callOrNewExpression && callOrNewExpression.expression === functionReference) {
+                        return callOrNewExpression;
                     }
                     break;
-                // Method call (x.foo(...))
+                // x.foo(...)
                 case SyntaxKind.PropertyAccessExpression:
                     const propertyAccessExpression = tryCast(parent, isPropertyAccessExpression);
                     if (propertyAccessExpression && propertyAccessExpression.parent && propertyAccessExpression.name === functionReference) {
-                        const callExpression = tryCast(propertyAccessExpression.parent, isCallExpression);
-                        if (callExpression && callExpression.expression === propertyAccessExpression) {
-                            return callExpression;
+                        const callOrNewExpression = tryCast(propertyAccessExpression.parent, isCallOrNewExpression);
+                        if (callOrNewExpression && callOrNewExpression.expression === propertyAccessExpression) {
+                            return callOrNewExpression;
                         }
                     }
                     break;
-                // Method call (x["foo"](...))
+                // x["foo"](...)
                 case SyntaxKind.ElementAccessExpression:
                     const elementAccessExpression = tryCast(parent, isElementAccessExpression);
                     if (elementAccessExpression && elementAccessExpression.parent && elementAccessExpression.argumentExpression === functionReference) {
-                        const callExpression = tryCast(elementAccessExpression.parent, isCallExpression);
-                        if (callExpression && callExpression.expression === elementAccessExpression) {
-                            return callExpression;
+                        const callOrNewExpression = tryCast(elementAccessExpression.parent, isCallOrNewExpression);
+                        if (callOrNewExpression && callOrNewExpression.expression === elementAccessExpression) {
+                            return callOrNewExpression;
                         }
                     }
                     break;
@@ -244,7 +264,7 @@ namespace ts.refactor.convertParamsToDestructuredObject {
 
     function getFunctionDeclarationAtPosition(file: SourceFile, startPosition: number, checker: TypeChecker): ValidFunctionDeclaration | undefined {
         const node = getTouchingToken(file, startPosition);
-        const functionDeclaration = getContainingFunction(node);
+        const functionDeclaration = getContainingFunctionDeclaration(node);
 
          // don't offer refactor on top-level JSDoc
         if (isTopLevelJSDoc(node)) return undefined;
@@ -267,25 +287,21 @@ namespace ts.refactor.convertParamsToDestructuredObject {
     }
 
     function isValidFunctionDeclaration(
-        functionDeclaration: SignatureDeclaration,
+        functionDeclaration: FunctionLikeDeclaration,
         checker: TypeChecker): functionDeclaration is ValidFunctionDeclaration {
         if (!isValidParameterNodeArray(functionDeclaration.parameters, checker)) return false;
         switch (functionDeclaration.kind) {
             case SyntaxKind.FunctionDeclaration:
+                return hasNameOrDefault(functionDeclaration) && isSingleImplementation(functionDeclaration, checker);
             case SyntaxKind.MethodDeclaration:
-                return !!functionDeclaration.name
-                    && !!functionDeclaration.body
-                    && !checker.isImplementationOfOverload(functionDeclaration);
+                return isSingleImplementation(functionDeclaration, checker);
             case SyntaxKind.Constructor:
                 if (isClassDeclaration(functionDeclaration.parent)) {
-                    return !!functionDeclaration.body
-                        && !!functionDeclaration.parent.name
-                        && !checker.isImplementationOfOverload(functionDeclaration);
+                    return hasNameOrDefault(functionDeclaration.parent) && isSingleImplementation(functionDeclaration, checker);
                 }
                 else {
                     return isValidVariableDeclaration(functionDeclaration.parent.parent)
-                        && !!functionDeclaration.body
-                        && !checker.isImplementationOfOverload(functionDeclaration);
+                        && isSingleImplementation(functionDeclaration, checker);
                 }
             case SyntaxKind.FunctionExpression:
             case SyntaxKind.ArrowFunction:
@@ -294,6 +310,18 @@ namespace ts.refactor.convertParamsToDestructuredObject {
         return false;
     }
 
+    function isSingleImplementation(functionDeclaration: FunctionLikeDeclaration, checker: TypeChecker): boolean {
+        return !!functionDeclaration.body && !checker.isImplementationOfOverload(functionDeclaration);
+    }
+
+    function hasNameOrDefault(functionOrClassDeclaration: FunctionDeclaration | ClassDeclaration): boolean {
+        if (!functionOrClassDeclaration.name) {
+            const defaultKeyword = findModifier(functionOrClassDeclaration, SyntaxKind.DefaultKeyword);
+            return !!defaultKeyword;
+        }
+        return true;
+    }
+
     function isValidParameterNodeArray(
         parameters: NodeArray<ParameterDeclaration>,
         checker: TypeChecker): parameters is ValidParameterNodeArray {
@@ -488,11 +516,17 @@ namespace ts.refactor.convertParamsToDestructuredObject {
         return getTextOfIdentifierOrLiteral(paramDeclaration.name);
     }
 
-    function getClassNames(constructorDeclaration: ValidConstructor): Identifier[] {
+    function getClassNames(constructorDeclaration: ValidConstructor): (Identifier | Modifier)[] {
         switch (constructorDeclaration.parent.kind) {
             case SyntaxKind.ClassDeclaration:
                 const classDeclaration = constructorDeclaration.parent;
-                return [classDeclaration.name];
+                if (classDeclaration.name) return [classDeclaration.name];
+                // If the class declaration doesn't have a name, it should have a default modifier.
+                // We validated this in `isValidFunctionDeclaration` through `hasNameOrDefault`
+                const defaultModifier = Debug.assertDefined(
+                    findModifier(classDeclaration, SyntaxKind.DefaultKeyword),
+                    "Nameless class declaration should be a default export");
+                return [defaultModifier];
             case SyntaxKind.ClassExpression:
                 const classExpression = constructorDeclaration.parent;
                 const variableDeclaration = constructorDeclaration.parent.parent;
@@ -505,10 +539,19 @@ namespace ts.refactor.convertParamsToDestructuredObject {
     function getFunctionNames(functionDeclaration: ValidFunctionDeclaration): Node[] {
         switch (functionDeclaration.kind) {
             case SyntaxKind.FunctionDeclaration:
+                if (functionDeclaration.name) return [functionDeclaration.name];
+                // If the function declaration doesn't have a name, it should have a default modifier.
+                // We validated this in `isValidFunctionDeclaration` through `hasNameOrDefault`
+                const defaultModifier = Debug.assertDefined(
+                    findModifier(functionDeclaration, SyntaxKind.DefaultKeyword),
+                    "Nameless function declaration should be a default export");
+                return [defaultModifier];
             case SyntaxKind.MethodDeclaration:
                 return [functionDeclaration.name];
             case SyntaxKind.Constructor:
-                const ctrKeyword = findChildOfKind(functionDeclaration, SyntaxKind.ConstructorKeyword, functionDeclaration.getSourceFile())!;
+                const ctrKeyword = Debug.assertDefined(
+                    findChildOfKind(functionDeclaration, SyntaxKind.ConstructorKeyword, functionDeclaration.getSourceFile()),
+                    "Constructor declaration should have constructor keyword");
                 if (functionDeclaration.parent.kind === SyntaxKind.ClassExpression) {
                     const variableDeclaration = functionDeclaration.parent.parent;
                     return [variableDeclaration.name, ctrKeyword];
@@ -532,13 +575,12 @@ namespace ts.refactor.convertParamsToDestructuredObject {
     }
 
     interface ValidConstructor extends ConstructorDeclaration {
-        parent: (ClassDeclaration & { name: Identifier }) | (ClassExpression & { parent: ValidVariableDeclaration });
+        parent: ClassDeclaration | (ClassExpression & { parent: ValidVariableDeclaration });
         parameters: NodeArray<ValidParameterDeclaration>;
         body: FunctionBody;
     }
 
     interface ValidFunction extends FunctionDeclaration {
-        name: Identifier;
         parameters: NodeArray<ValidParameterDeclaration>;
         body: FunctionBody;
     }

src/services/utilities.ts

@@ -1664,10 +1664,15 @@ namespace ts {
         return ensureScriptKind(fileName, host && host.getScriptKind && host.getScriptKind(fileName));
     }
 
-    export function getSymbolTarget(symbol: Symbol): Symbol {
+    export function getSymbolTarget(symbol: Symbol, checker: TypeChecker): Symbol {
         let next: Symbol = symbol;
-        while (isTransientSymbol(next) && next.target) {
-           next = next.target;
+        while (isAliasSymbol(next) || (isTransientSymbol(next) && next.target)) {
+            if (isTransientSymbol(next) && next.target) {
+                next = next.target;
+            }
+            else {
+                next = skipAlias(next, checker);
+            }
         }
         return next;
     }
@@ -1676,6 +1681,10 @@ namespace ts {
         return (symbol.flags & SymbolFlags.Transient) !== 0;
     }
 
+    function isAliasSymbol(symbol: Symbol): boolean {
+        return (symbol.flags & SymbolFlags.Alias) !== 0;
+    }
+
     export function getUniqueSymbolId(symbol: Symbol, checker: TypeChecker) {
         return getSymbolId(skipAlias(symbol, checker));
     }

tests/cases/fourslash/refactorConvertParamsToDestructuredObject_badRestParam.ts

@@ -14,7 +14,7 @@
 ////}
 
 goTo.select("a", "b");
-verify.not.refactorAvailable("Convert to named parameters");
+verify.not.refactorAvailable("Convert parameters to destructured object");
 
 goTo.select("c", "d");
-verify.not.refactorAvailable("Convert to named parameters");
+verify.not.refactorAvailable("Convert parameters to destructured object");

tests/cases/fourslash/refactorConvertParamsToDestructuredObject_importedFunction.ts

@@ -0,0 +1,24 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: f.ts
+////export function f(/*a*/a: number, b: string/*b*/): string {
+////    return b;
+////}
+
+// @Filename: a.ts
+////import { f as g } from "./f";
+////g(4, "b");
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert parameters to destructured object",
+    actionName: "Convert parameters to destructured object",
+    actionDescription: "Convert parameters to destructured object",
+    newContent: `export function f({ a, b }: { a: number; b: string; }): string {
+    return b;
+}`
+});
+
+goTo.file("a.ts");
+verify.currentFileContentIs(`import { f as g } from "./f";
+g({ a: 4, b: "b" });`)

tests/cases/fourslash/refactorConvertParamsToDestructuredObject_importedFunction2.ts

@@ -0,0 +1,24 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: f.ts
+////export default function f(/*a*/a: number, b: string/*b*/): string {
+////    return b;
+////}
+
+// @Filename: a.ts
+////import g from "./f";
+////g(4, "b");
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert parameters to destructured object",
+    actionName: "Convert parameters to destructured object",
+    actionDescription: "Convert parameters to destructured object",
+    newContent: `export default function f({ a, b }: { a: number; b: string; }): string {
+    return b;
+}`
+});
+
+goTo.file("a.ts");
+verify.currentFileContentIs(`import g from "./f";
+g({ a: 4, b: "b" });`)

tests/cases/fourslash/refactorConvertParamsToDestructuredObject_importedFunction3.ts

@@ -0,0 +1,23 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: f.ts
+////function foo(/*a*/a: string, b: string/*b*/) { }
+////export = foo;
+
+// @Filename: a.ts
+////import bar = require("./f");
+////bar("a", "b");
+
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert parameters to destructured object",
+    actionName: "Convert parameters to destructured object",
+    actionDescription: "Convert parameters to destructured object",
+    newContent: `function foo({ a, b }: { a: string; b: string; }) { }
+export = foo;`
+});
+
+goTo.file("a.ts");
+verify.currentFileContentIs(`import bar = require("./f");
+bar({ a: "a", b: "b" });`)

tests/cases/fourslash/refactorConvertParamsToDestructuredObject_importedFunction4.ts

@@ -0,0 +1,27 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: f.ts
+////export { foo as default };
+////function /*a*/foo/*b*/(a: number, b: number) {
+////    return a + b;
+////}
+
+// @Filename: a.ts
+////import bar from "./f";
+////bar(1, 2);
+
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert parameters to destructured object",
+    actionName: "Convert parameters to destructured object",
+    actionDescription: "Convert parameters to destructured object",
+    newContent: `export { foo as default };
+function foo({ a, b }: { a: number; b: number; }) {
+    return a + b;
+}`
+});
+
+goTo.file("a.ts");
+verify.currentFileContentIs(`import bar from "./f";
+bar({ a: 1, b: 2 });`)