fixUnusedIdentifier: Remove unused writes (microsoft#24805)

Andy · web-flow · commit e821d613a18f · 2018-06-08T15:20:33.000-07:00
diff --git a/src/services/codefixes/fixUnusedIdentifier.ts b/src/services/codefixes/fixUnusedIdentifier.ts
@@ -152,6 +152,7 @@ namespace ts.codefix {
         switch (token.kind) {
             case SyntaxKind.Identifier:
                 tryDeleteIdentifier(changes, sourceFile, <Identifier>token, deletedAncestors, checker, isFixAll);
+                deleteAssignments(changes, sourceFile, token as Identifier, checker);
                 break;
             case SyntaxKind.PropertyDeclaration:
             case SyntaxKind.NamespaceImport:
@@ -163,6 +164,15 @@ namespace ts.codefix {
         }
     }
 
+    function deleteAssignments(changes: textChanges.ChangeTracker, sourceFile: SourceFile, token: Identifier, checker: TypeChecker) {
+        FindAllReferences.Core.eachSymbolReferenceInFile(token, checker, sourceFile, (ref: Node) => {
+            if (ref.parent.kind === SyntaxKind.PropertyAccessExpression) ref = ref.parent;
+            if (ref.parent.kind === SyntaxKind.BinaryExpression && ref.parent.parent.kind === SyntaxKind.ExpressionStatement) {
+                changes.deleteNode(sourceFile, ref.parent.parent);
+            }
+        });
+    }
+
     function tryDeleteDefault(changes: textChanges.ChangeTracker, sourceFile: SourceFile, token: Node, deletedAncestors: NodeSet | undefined): void {
         if (isDeclarationName(token)) {
             if (deletedAncestors) deletedAncestors.add(token.parent);
diff --git a/tests/cases/fourslash/codeFixUnusedIdentifier_deleteWrite.ts b/tests/cases/fourslash/codeFixUnusedIdentifier_deleteWrite.ts
@@ -0,0 +1,24 @@
+/// <reference path='fourslash.ts' />
+
+// @noLib: true
+// @noUnusedLocals: true
+
+////let x = 0;
+////x = 1;
+////
+////export class C {
+////    private p: number;
+////
+////    m() { this.p = 0; }
+////}
+
+verify.codeFixAll({
+    fixId: "unusedIdentifier_delete",
+    fixAllDescription: "Delete all unused declarations",
+    newFileContent:
+`
+export class C {
+
+    m() { }
+}`,
+});
