support assignment pattern

typescript-eslint · Apr 13, 2024 · 012fcfd · 012fcfd
1 parent 95cbd19
commit 012fcfd
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Showing 2 changed files with 43 additions and 16 deletions.
diff --git a/packages/eslint-plugin/src/rules/no-unnecessary-parameter-property-assignment.ts b/packages/eslint-plugin/src/rules/no-unnecessary-parameter-property-assignment.ts
@@ -93,6 +93,29 @@ export default createRule<[], MessageIds>({
       );
     }
 
+    function isReferenceFromParameter(node: TSESTree.Identifier): boolean {
+      const scope = context.sourceCode.getScope(node);
+
+      const rightRef = scope.references.find(
+        ref => ref.identifier.name === node.name,
+      );
+      return rightRef?.resolved?.defs.at(0)?.type === DefinitionType.Parameter;
+    }
+
+    function isParameterPropertyWithName(
+      node: TSESTree.Parameter,
+      name: string,
+    ): boolean {
+      return (
+        node.type === AST_NODE_TYPES.TSParameterProperty &&
+        ((node.parameter.type === AST_NODE_TYPES.Identifier && // constructor (public foo) {}
+          node.parameter.name === name) ||
+          (node.parameter.type === AST_NODE_TYPES.AssignmentPattern && // constructor (public foo = 1) {}
+            node.parameter.left.type === AST_NODE_TYPES.Identifier &&
+            node.parameter.left.name === name))
+      );
+    }
+
     return {
       ClassBody(): void {
         reportInfoStack.push({
@@ -184,26 +207,14 @@ export default createRule<[], MessageIds>({
 
         if (
           right.type !== AST_NODE_TYPES.Identifier ||
-          leftName !== right.name
+          leftName !== right.name ||
+          !isReferenceFromParameter(right)
         ) {
           return;
         }
 
-        const scope = context.sourceCode.getScope(right);
-
-        const rightRef = scope.references.find(
-          ref => ref.identifier.name === right.name,
-        );
-
-        if (rightRef?.resolved?.defs.at(0)?.type !== DefinitionType.Parameter) {
-          return;
-        }
-
-        const hasParameterPropety = functionNode.params.some(
-          p =>
-            p.type === AST_NODE_TYPES.TSParameterProperty &&
-            p.parameter.type === AST_NODE_TYPES.Identifier &&
-            p.parameter.name === right.name,
+        const hasParameterPropety = functionNode.params.some(param =>
+          isParameterPropertyWithName(param, right.name),
         );
 
         if (hasParameterPropety) {

diff --git a/packages/eslint-plugin/tests/rules/no-unnecessary-parameter-property-assignment.test.ts b/packages/eslint-plugin/tests/rules/no-unnecessary-parameter-property-assignment.test.ts
@@ -191,6 +191,22 @@ class Foo {
     },
     {
       code: `
+class Foo {
+  constructor(public foo = '') {
+    this.foo = foo;
+  }
+}
+      `,
+      errors: [
+        {
+          line: 4,
+          column: 5,
+          messageId: 'unnecessaryAssign',
+        },
+      ],
+    },
+    {
+      code: `
 class Foo {
   constructor(public foo: string) {
     this.foo ||= foo;