fix: add support for parameters with a default value (#784)

typescript-eslint · Jul 31, 2019 · 71b37c1 · 71b37c1
1 parent b731df9
commit 71b37c1
Show file tree

Hide file tree

Showing 2 changed files with 16 additions and 4 deletions.
diff --git a/packages/eslint-plugin/src/rules/typedef.ts b/packages/eslint-plugin/src/rules/typedef.ts
@@ -69,10 +69,21 @@ export default util.createRule<[Options], MessageIds>({
 
     function checkParameters(params: TSESTree.Parameter[]) {
       for (const param of params) {
-        if (
-          param.type !== AST_NODE_TYPES.TSParameterProperty &&
-          !param.typeAnnotation
-        ) {
+        let annotationNode: TSESTree.Node | undefined;
+
+        switch (param.type) {
+          case AST_NODE_TYPES.AssignmentPattern:
+            annotationNode = param.left;
+            break;
+          case AST_NODE_TYPES.TSParameterProperty:
+            annotationNode = undefined;
+            break;
+          default:
+            annotationNode = param;
+            break;
+        }
+
+        if (annotationNode !== undefined && !annotationNode.typeAnnotation) {
           report(param, getNodeName(param));
         }
       }

diff --git a/packages/eslint-plugin/tests/rules/typedef.test.ts b/packages/eslint-plugin/tests/rules/typedef.test.ts
@@ -108,6 +108,7 @@ ruleTester.run('typedef', rule, {
     `function receivesNumbers([a, b]: number[]): void { }`,
     `function receivesString({ a }: { a: string }): void { }`,
     `function receivesStrings({ a, b }: { [i: string ]: string }): void { }`,
+    `function receivesNumber(a: number = 123): void { }`,
     // Property declarations
     `type Test = {
        member: number;