[Fix] no-extraneous-dependencies/TypeScript: do not error when impo…

…rting type from dev dependencies

Fixes #1618.

CHANGELOG.md

@@ -8,6 +8,9 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 ### Added
 - [`no-unused-modules`]: consider exported TypeScript interfaces, types and enums ([#1819], thanks [@nicolashenry])
 
+### Fixed
+- [`no-extraneous-dependencies`]/TypeScript: do not error when importing type from dev dependencies ([#1820], thanks [@fernandopasik])
+
 ## [2.21.2] - 2020-06-09
 ### Fixed
 - [`order`]: avoid a crash on TypeScript’s `export import` syntax ([#1808], thanks [@ljharb])
@@ -704,6 +707,7 @@ for info on changes for earlier releases.
 
 [`memo-parser`]: ./memo-parser/README.md
 
+[#1820]: https://github.com/benmosher/eslint-plugin-import/pull/1820
 [#1819]: https://github.com/benmosher/eslint-plugin-import/pull/1819
 [#1802]: https://github.com/benmosher/eslint-plugin-import/pull/1802
 [#1801]: https://github.com/benmosher/eslint-plugin-import/issues/1801
@@ -1220,3 +1224,4 @@ for info on changes for earlier releases.
 [@Maxim-Mazurok]: https://github.com/Maxim-Mazurok
 [@malykhinvi]: https://github.com/malykhinvi
 [@nicolashenry]: https://github.com/nicolashenry
+[@fernandopasik]: https://github.com/fernandopasik

src/rules/no-extraneous-dependencies.js

@@ -111,7 +111,7 @@ function optDepErrorMessage(packageName) {
 
 function reportIfMissing(context, deps, depsOptions, node, name) {
   // Do not report when importing types
-  if (node.importKind === 'type') {
+  if (node.importKind === 'type' || (node.parent && node.parent.importKind === 'type')) {
     return
   }
 

tests/files/with-typescript-dev-dependencies/package.json

@@ -0,0 +1,5 @@
+{
+  "devDependencies": {
+    "@types/json-schema": "*"
+  }
+}

tests/src/rules/no-extraneous-dependencies.js

@@ -1,4 +1,4 @@
-import { test } from '../utils'
+import { getTSParsers, test } from '../utils'
 import * as path from 'path'
 import * as fs from 'fs'
 
@@ -17,6 +17,7 @@ const packageFileWithSyntaxErrorMessage = (() => {
   }
 })()
 const packageDirWithFlowTyped = path.join(__dirname, '../../files/with-flow-typed')
+const packageDirWithTypescriptDevDependencies = path.join(__dirname, '../../files/with-typescript-dev-dependencies')
 const packageDirMonoRepoRoot = path.join(__dirname, '../../files/monorepo')
 const packageDirMonoRepoWithNested = path.join(__dirname, '../../files/monorepo/packages/nested-package')
 const packageDirWithEmpty = path.join(__dirname, '../../files/empty')
@@ -312,3 +313,56 @@ ruleTester.run('no-extraneous-dependencies', rule, {
     }),
   ],
 })
+
+describe('TypeScript', function () {
+  getTSParsers()
+    .forEach((parser) => {
+      const parserConfig = {
+        parser: parser,
+        settings: {
+          'import/parsers': { [parser]: ['.ts'] },
+          'import/resolver': { 'eslint-import-resolver-typescript': true },
+        },
+      }
+
+      if (parser !== require.resolve('typescript-eslint-parser')) {
+        ruleTester.run('no-extraneous-dependencies', rule, {
+          valid: [
+            test(Object.assign({
+              code: 'import type { JSONSchema7Type } from "@types/json-schema";',
+              options: [{packageDir: packageDirWithTypescriptDevDependencies, devDependencies: false }],
+            }, parserConfig)),
+          ],
+          invalid: [
+            test(Object.assign({
+              code: 'import { JSONSchema7Type } from "@types/json-schema";',
+              options: [{packageDir: packageDirWithTypescriptDevDependencies, devDependencies: false }],
+              errors: [{
+                message: "'@types/json-schema' should be listed in the project's dependencies, not devDependencies.",
+              }],
+            }, parserConfig)),
+          ],
+        })
+      } else {
+        ruleTester.run('no-extraneous-dependencies', rule, {
+          valid: [],
+          invalid: [
+            test(Object.assign({
+              code: 'import { JSONSchema7Type } from "@types/json-schema";',
+              options: [{packageDir: packageDirWithTypescriptDevDependencies, devDependencies: false }],
+              errors: [{
+                message: "'@types/json-schema' should be listed in the project's dependencies, not devDependencies.",
+              }],
+            }, parserConfig)),
+            test(Object.assign({
+              code: 'import type { JSONSchema7Type } from "@types/json-schema";',
+              options: [{packageDir: packageDirWithTypescriptDevDependencies, devDependencies: false }],
+              errors: [{
+                message: "'@types/json-schema' should be listed in the project's dependencies, not devDependencies.",
+              }],
+            }, parserConfig)),
+          ],
+        })
+      }
+    })
+})