Handle BindingElement in fixUnusedIdentifier (microsoft#23819)

* Handle BindingElement in fixUnusedIdentifier

* Add array destructure tests

Author: Andy

src/services/codefixes/fixUnusedIdentifier.ts

@@ -171,6 +171,21 @@ namespace ts.codefix {
                 }
                 break;
 
+            case SyntaxKind.BindingElement: {
+                const pattern = (parent as BindingElement).parent;
+                switch (pattern.kind) {
+                    case SyntaxKind.ArrayBindingPattern:
+                        changes.deleteNode(sourceFile, parent); // Don't delete ','
+                        break;
+                    case SyntaxKind.ObjectBindingPattern:
+                        changes.deleteNodeInList(sourceFile, parent);
+                        break;
+                    default:
+                        return Debug.assertNever(pattern);
+                }
+                break;
+            }
+
             // handle case where 'import a = A;'
             case SyntaxKind.ImportEqualsDeclaration:
                 const importEquals = getAncestor(identifier, SyntaxKind.ImportEqualsDeclaration);

src/services/formatting/smartIndenter.ts

@@ -327,9 +327,10 @@ namespace ts.formatting {
 
         export function getContainingList(node: Node, sourceFile: SourceFile): NodeArray<Node> {
             if (node.parent) {
+                const { end } = node;
                 switch (node.parent.kind) {
                     case SyntaxKind.TypeReference:
-                        return getListIfStartEndIsInListRange((<TypeReferenceNode>node.parent).typeArguments, node.getStart(sourceFile), node.getEnd());
+                        return getListIfStartEndIsInListRange((<TypeReferenceNode>node.parent).typeArguments, node.getStart(sourceFile), end);
                     case SyntaxKind.ObjectLiteralExpression:
                         return (<ObjectLiteralExpression>node.parent).properties;
                     case SyntaxKind.ArrayLiteralExpression:
@@ -344,22 +345,25 @@ namespace ts.formatting {
                     case SyntaxKind.ConstructorType:
                     case SyntaxKind.ConstructSignature: {
                         const start = node.getStart(sourceFile);
-                        return getListIfStartEndIsInListRange((<SignatureDeclaration>node.parent).typeParameters, start, node.getEnd()) ||
-                            getListIfStartEndIsInListRange((<SignatureDeclaration>node.parent).parameters, start, node.getEnd());
+                        return getListIfStartEndIsInListRange((<SignatureDeclaration>node.parent).typeParameters, start, end) ||
+                            getListIfStartEndIsInListRange((<SignatureDeclaration>node.parent).parameters, start, end);
                     }
                     case SyntaxKind.ClassDeclaration:
-                        return getListIfStartEndIsInListRange((<ClassDeclaration>node.parent).typeParameters, node.getStart(sourceFile), node.getEnd());
+                        return getListIfStartEndIsInListRange((<ClassDeclaration>node.parent).typeParameters, node.getStart(sourceFile), end);
                     case SyntaxKind.NewExpression:
                     case SyntaxKind.CallExpression: {
                         const start = node.getStart(sourceFile);
-                        return getListIfStartEndIsInListRange((<CallExpression>node.parent).typeArguments, start, node.getEnd()) ||
-                            getListIfStartEndIsInListRange((<CallExpression>node.parent).arguments, start, node.getEnd());
+                        return getListIfStartEndIsInListRange((<CallExpression>node.parent).typeArguments, start, end) ||
+                            getListIfStartEndIsInListRange((<CallExpression>node.parent).arguments, start, end);
                     }
                     case SyntaxKind.VariableDeclarationList:
-                        return getListIfStartEndIsInListRange((<VariableDeclarationList>node.parent).declarations, node.getStart(sourceFile), node.getEnd());
+                        return getListIfStartEndIsInListRange((<VariableDeclarationList>node.parent).declarations, node.getStart(sourceFile), end);
                     case SyntaxKind.NamedImports:
                     case SyntaxKind.NamedExports:
-                        return getListIfStartEndIsInListRange((<NamedImportsOrExports>node.parent).elements, node.getStart(sourceFile), node.getEnd());
+                        return getListIfStartEndIsInListRange((<NamedImportsOrExports>node.parent).elements, node.getStart(sourceFile), end);
+                    case SyntaxKind.ObjectBindingPattern:
+                    case SyntaxKind.ArrayBindingPattern:
+                        return getListIfStartEndIsInListRange((<ObjectBindingPattern | ArrayBindingPattern>node.parent).elements, node.getStart(sourceFile), end);
                 }
             }
             return undefined;

tests/cases/fourslash/codeFixUnusedIdentifier_destructure_partlyUnused.ts

@@ -0,0 +1,75 @@
+/// <reference path='fourslash.ts' />
+
+// @noUnusedLocals: true
+
+////{
+////    const { x, y } = o;
+////    x;
+////}
+////{
+////    const { x, y } = o;
+////    y;
+////}
+////{
+////    const { x, y, z } = o;
+////    y;
+////}
+////{
+////    const { x, y, z } = o;
+////    x; z;
+////}
+////{
+////    const [x, y] = o;
+////    x;
+////}
+////{
+////    const [x, y] = o;
+////    y;
+////}
+////{
+////    const [x, y, z] = o;
+////    y;
+////}
+////{
+////    const [x, y, z] = o;
+////    x; z;
+////}
+
+
+verify.codeFixAll({
+    fixId: "unusedIdentifier_delete",
+    fixAllDescription: "Delete all unused declarations",
+    newFileContent:
+`{
+    const { x } = o;
+    x;
+}
+{
+    const { y } = o;
+    y;
+}
+{
+    const { y } = o;
+    y;
+}
+{
+    const { x, z } = o;
+    x; z;
+}
+{
+    const [x,] = o;
+    x;
+}
+{
+    const [, y] = o;
+    y;
+}
+{
+    const [, y,] = o;
+    y;
+}
+{
+    const [x,, z] = o;
+    x; z;
+}`,
+});