consider exported TypeScript interfaces, types and enums

CHANGELOG.md

@@ -5,6 +5,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This change log adheres to standards from [Keep a CHANGELOG](http://keepachangelog.com).
 
 ## [Unreleased]
+### Fixed
+- [`no-unused-modules`]: consider exported TypeScript interfaces, types and enums ([#1680], thanks [@nicolashenry])
 
 ## [2.21.2] - 2020-06-09
 ### Fixed

src/rules/no-unused-modules.js

@@ -63,6 +63,11 @@ const IMPORT_DEFAULT_SPECIFIER = 'ImportDefaultSpecifier'
 const VARIABLE_DECLARATION = 'VariableDeclaration'
 const FUNCTION_DECLARATION = 'FunctionDeclaration'
 const CLASS_DECLARATION = 'ClassDeclaration'
+const INTERFACE_DECLARATION = 'InterfaceDeclaration'
+const TYPE_ALIAS = 'TypeAlias'
+const TS_INTERFACE_DECLARATION = 'TSInterfaceDeclaration'
+const TS_TYPE_ALIAS_DECLARATION = 'TSTypeAliasDeclaration'
+const TS_ENUM_DECLARATION = 'TSEnumDeclaration'
 const DEFAULT = 'default'
 
 /**
@@ -562,7 +567,12 @@ module.exports = {
           if (declaration) {
             if (
               declaration.type === FUNCTION_DECLARATION ||
-              declaration.type === CLASS_DECLARATION
+              declaration.type === CLASS_DECLARATION ||
+              declaration.type === INTERFACE_DECLARATION ||
+              declaration.type === TYPE_ALIAS ||
+              declaration.type === TS_INTERFACE_DECLARATION ||
+              declaration.type === TS_TYPE_ALIAS_DECLARATION ||
+              declaration.type === TS_ENUM_DECLARATION
             ) {
               newExportIdentifiers.add(declaration.id.name)
             }
@@ -886,7 +896,12 @@ module.exports = {
         if (node.declaration) {
           if (
             node.declaration.type === FUNCTION_DECLARATION ||
-            node.declaration.type === CLASS_DECLARATION
+            node.declaration.type === CLASS_DECLARATION ||
+            node.declaration.type === INTERFACE_DECLARATION ||
+            node.declaration.type === TYPE_ALIAS ||
+            node.declaration.type === TS_INTERFACE_DECLARATION ||
+            node.declaration.type === TS_TYPE_ALIAS_DECLARATION ||
+            node.declaration.type === TS_ENUM_DECLARATION
           ) {
             checkUsage(node, node.declaration.id.name)
           }

tests/files/no-unused-modules/typescript/file-ts-a.ts

@@ -1,3 +1,8 @@
 import {b} from './file-ts-b';
+import {c} from './file-ts-c';
+import {d} from './file-ts-d';
+import {e} from './file-ts-e';
 
-export const a = b + 1;
+export const a = b + 1 + e.f;
+export const a2: c = {};
+export const a3: d = {};

tests/files/no-unused-modules/typescript/file-ts-c.ts

@@ -0,0 +1 @@
+export interface c {};

tests/files/no-unused-modules/typescript/file-ts-d.ts

@@ -0,0 +1 @@
+export type d = {};

tests/files/no-unused-modules/typescript/file-ts-e.ts

@@ -0,0 +1 @@
+export enum e { f };

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

@@ -1,4 +1,4 @@
-import { test, testFilePath } from '../utils'
+import { test, testFilePath, getTSParsers } from '../utils'
 import jsxConfig from '../../../config/react'
 import typescriptConfig from '../../../config/typescript'
 
@@ -736,10 +736,81 @@ describe('correctly work with Typescript only files', () => {
           error(`exported declaration 'b' not used within other modules`),
         ],
       }),
+      test({
+        options: unusedExportsTypescriptOptions,
+        code: `export interface c {};`,
+        parser: require.resolve('babel-eslint'),
+        filename: testFilePath('./no-unused-modules/typescript/file-ts-c.ts'),
+        errors: [
+          error(`exported declaration 'c' not used within other modules`),
+        ],
+      }),
+      test({
+        options: unusedExportsTypescriptOptions,
+        code: `export type d = {};`,
+        parser: require.resolve('babel-eslint'),
+        filename: testFilePath('./no-unused-modules/typescript/file-ts-d.ts'),
+        errors: [
+          error(`exported declaration 'd' not used within other modules`),
+        ],
+      }),
     ],
   })
 })
 
+context('TypeScript', function () {
+  getTSParsers().forEach((parser) => {
+    typescriptRuleTester.run('no-unused-modules', rule, {
+      valid: [
+        test({
+          options: unusedExportsTypescriptOptions,
+          code: 'import a from "file-ts-a";',
+          parser: parser,
+          filename: testFilePath('./no-unused-modules/typescript/file-ts-a.ts'),
+        }),
+      ],
+      invalid: [
+        test({
+          options: unusedExportsTypescriptOptions,
+          code: `export const b = 2;`,
+          parser: parser,
+          filename: testFilePath('./no-unused-modules/typescript/file-ts-b.ts'),
+          errors: [
+            error(`exported declaration 'b' not used within other modules`),
+          ],
+        }),
+        test({
+          options: unusedExportsTypescriptOptions,
+          code: `export interface c {};`,
+          parser: parser,
+          filename: testFilePath('./no-unused-modules/typescript/file-ts-c.ts'),
+          errors: [
+            error(`exported declaration 'c' not used within other modules`),
+          ],
+        }),
+        test({
+          options: unusedExportsTypescriptOptions,
+          code: `export type d = {};`,
+          parser: parser,
+          filename: testFilePath('./no-unused-modules/typescript/file-ts-d.ts'),
+          errors: [
+            error(`exported declaration 'd' not used within other modules`),
+          ],
+        }),
+        test({
+          options: unusedExportsTypescriptOptions,
+          code: `export enum e { f };`,
+          parser: parser,
+          filename: testFilePath('./no-unused-modules/typescript/file-ts-e.ts'),
+          errors: [
+            error(`exported declaration 'e' not used within other modules`),
+          ],
+        }),
+      ],
+    })
+  })
+})
+
 describe('correctly work with JSX only files', () => {
   jsxRuleTester.run('no-unused-modules', rule, {
     valid: [