Fix: Handle extends generics in no-unused-vars (typescript-eslint#135)

armanio123 · Jan 18, 2019 · 8fddb6d · 8fddb6d
1 parent 1690342
commit 8fddb6d
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diff --git a/packages/eslint-plugin-typescript/lib/rules/no-unused-vars.js b/packages/eslint-plugin-typescript/lib/rules/no-unused-vars.js
@@ -122,6 +122,15 @@ module.exports = {
 
                     break;
 
+                case "TSTypeParameter": {
+                    markTypeAnnotationAsUsed(annotation.constraint);
+                    break;
+                }
+                case "TSMappedType": {
+                    markTypeAnnotationAsUsed(annotation.typeAnnotation);
+                    markTypeAnnotationAsUsed(annotation.typeParameter);
+                    break;
+                }
                 default:
                     break;
             }
@@ -247,6 +256,9 @@ module.exports = {
             if (node.decorators) {
                 node.decorators.forEach(markDecoratorAsUsed);
             }
+            if (node.typeParameters && node.typeParameters.params) {
+                node.typeParameters.params.forEach(markTypeAnnotationAsUsed);
+            }
         }
 
         //----------------------------------------------------------------------

diff --git a/packages/eslint-plugin-typescript/tests/lib/rules/no-unused-vars.js b/packages/eslint-plugin-typescript/tests/lib/rules/no-unused-vars.js
@@ -315,6 +315,30 @@ import { SomeOther } from 'some';
 import { Another } from 'some';
 interface A extends Nullable<SomeOther> {
     do(a: Nullable<Another>);
+}
+        `,
+        `
+import { Foo } from './types';
+
+class Bar<T extends Foo> {}
+
+new Bar<number>()
+        `,
+        `
+import { Foo, Bar } from './types';
+
+class Baz<T extends Foo & Bar> {}
+
+new Baz<any>()
+        `,
+        `
+type Foo = "a" | "b" | "c"
+type Bar = number
+
+export const map: { [name in Foo]: Bar } = {
+    a: 1,
+    b: 2,
+    c: 3
 }
         `
     ],