[Fix] no-unused-modules: Support destructuring

Author: s-h-a-d-o-w

src/rules/no-unused-modules.js

@@ -4,7 +4,7 @@
  * @author René Fermann
  */
 
-import Exports from '../ExportMap';
+import Exports, { recursivePatternCapture } from '../ExportMap';
 import { getFileExtensions } from 'eslint-module-utils/ignore';
 import resolve from 'eslint-module-utils/resolve';
 import docsUrl from '../docsUrl';
@@ -63,6 +63,8 @@ const IMPORT_DEFAULT_SPECIFIER = 'ImportDefaultSpecifier';
 const VARIABLE_DECLARATION = 'VariableDeclaration';
 const FUNCTION_DECLARATION = 'FunctionDeclaration';
 const CLASS_DECLARATION = 'ClassDeclaration';
+const IDENTIFIER = 'Identifier';
+const OBJECT_PATTERN = 'ObjectPattern';
 const TS_INTERFACE_DECLARATION = 'TSInterfaceDeclaration';
 const TS_TYPE_ALIAS_DECLARATION = 'TSTypeAliasDeclaration';
 const TS_ENUM_DECLARATION = 'TSEnumDeclaration';
@@ -80,7 +82,15 @@ function forEachDeclarationIdentifier(declaration, cb) {
       cb(declaration.id.name);
     } else if (declaration.type === VARIABLE_DECLARATION) {
       declaration.declarations.forEach(({ id }) => {
-        cb(id.name);
+        if(id.type === OBJECT_PATTERN) {
+          recursivePatternCapture(id, (pattern) => {
+            if (pattern.type === IDENTIFIER) {
+              cb(pattern.name);
+            }
+          });
+        } else {
+          cb(id.name);
+        }
       });
     }
   }

tests/files/no-unused-modules/destructuring-a.js

@@ -0,0 +1 @@
+import {a, b} from "./destructuring-b";

tests/files/no-unused-modules/destructuring-b.js

@@ -0,0 +1,2 @@
+const obj = {a: 1, dummy: {b: 2}};
+export const {a, dummy: {b}} = obj;

tests/src/rules/no-unused-modules.js

@@ -965,3 +965,23 @@ describe('ignore flow types', () => {
     invalid: [],
   });
 });
+
+describe('support (nested) destructuring assignment', () => {
+  ruleTester.run('no-unused-modules', rule, {
+    valid: [
+      test({
+        options: unusedExportsOptions,
+        code: 'import {a, b} from "./destructuring-b";',
+        parser: require.resolve('babel-eslint'),
+        filename: testFilePath('./no-unused-modules/destructuring-a.js'),
+      }),
+      test({
+        options: unusedExportsOptions,
+        code: 'const obj = {a: 1, dummy: {b: 2}}; export const {a, dummy: {b}} = obj;',
+        parser: require.resolve('babel-eslint'),
+        filename: testFilePath('./no-unused-modules/destructuring-b.js'),
+      }),
+    ],
+    invalid: [],
+  });
+});