Add array destructure tests

Author: Andy Hanson

src/services/codefixes/fixUnusedIdentifier.ts

@@ -171,9 +171,20 @@ namespace ts.codefix {
                 }
                 break;
 
-            case SyntaxKind.BindingElement:
-                changes.deleteNodeInList(sourceFile, parent);
+            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:

tests/cases/fourslash/codeFixUnusedIdentifier_destructure_partlyUnused.ts

@@ -10,6 +10,31 @@
 ////    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",
@@ -22,5 +47,29 @@ verify.codeFixAll({
 {
     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;
 }`,
 });