From 16f678b6786e15b55a6e5985b112b785aba20898 Mon Sep 17 00:00:00 2001
From: Tim Fischbach <tfischbach@codevise.de>
Date: Tue, 3 Apr 2018 12:28:12 +0200
Subject: [PATCH] Do not report type imports from flow-typed packages

When importing types from packages that are defined in a file inside
the `flow-typed` directory, prevent the `named` rule from reporting
that the package itself does not provide an export with that name.

Currently there is support for type imports from local files. Restrict
these checks to imports with relative paths.
---
 src/rules/named.js                                     | 10 ++++++++++
 .../flow-typed/npm/myflowtyped_v1.x.x.js               |  4 +++-
 .../with-flow-typed/node_modules/myflowtyped/index.js  |  1 +
 .../node_modules/myflowtyped/package.json              |  5 +++++
 tests/files/with-flow-typed/package.json               |  4 +++-
 tests/src/rules/named.js                               |  8 ++++++++
 6 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 tests/files/with-flow-typed/node_modules/myflowtyped/index.js
 create mode 100644 tests/files/with-flow-typed/node_modules/myflowtyped/package.json

diff --git a/src/rules/named.js b/src/rules/named.js
index aa17dfb406..7c2c4f624e 100644
--- a/src/rules/named.js
+++ b/src/rules/named.js
@@ -18,6 +18,8 @@ module.exports = {
         return // no named imports/exports
       }
 
+      if (isTypeFromPackage(node)) return
+
       const imports = Exports.get(node.source.value, context)
       if (imports == null) return
 
@@ -47,6 +49,14 @@ module.exports = {
       })
     }
 
+    function isTypeFromPackage(node) {
+      return node.importKind === 'type' && !hasRelativePath(node.source)
+    }
+
+    function hasRelativePath(source) {
+      return source.value.match(/^\.\//)
+    }
+
     return {
       'ImportDeclaration': checkSpecifiers.bind( null
                                                , 'imported'
diff --git a/tests/files/with-flow-typed/flow-typed/npm/myflowtyped_v1.x.x.js b/tests/files/with-flow-typed/flow-typed/npm/myflowtyped_v1.x.x.js
index 2917b03f51..8ef42f3d21 100644
--- a/tests/files/with-flow-typed/flow-typed/npm/myflowtyped_v1.x.x.js
+++ b/tests/files/with-flow-typed/flow-typed/npm/myflowtyped_v1.x.x.js
@@ -1,4 +1,6 @@
 // flow-typed signature: ____
 // flow-typed version: ____/myflowtyped_v1.x.x/flow_>=v0.33.x
 
-declare module 'myflowtyped' {}
+declare module 'myflowtyped' {
+  declare export type MyType = boolean;
+}
diff --git a/tests/files/with-flow-typed/node_modules/myflowtyped/index.js b/tests/files/with-flow-typed/node_modules/myflowtyped/index.js
new file mode 100644
index 0000000000..382cd024a3
--- /dev/null
+++ b/tests/files/with-flow-typed/node_modules/myflowtyped/index.js
@@ -0,0 +1 @@
+export const MyFlowTyped = {};
diff --git a/tests/files/with-flow-typed/node_modules/myflowtyped/package.json b/tests/files/with-flow-typed/node_modules/myflowtyped/package.json
new file mode 100644
index 0000000000..c23601c33c
--- /dev/null
+++ b/tests/files/with-flow-typed/node_modules/myflowtyped/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "myflowtyped",
+  "version": "1.0.0",
+  "main": "index.js"
+}
diff --git a/tests/files/with-flow-typed/package.json b/tests/files/with-flow-typed/package.json
index 18a1e415e5..b4151a4a4f 100644
--- a/tests/files/with-flow-typed/package.json
+++ b/tests/files/with-flow-typed/package.json
@@ -1,3 +1,5 @@
 {
-  "dependencies": {}
+  "dependencies": {
+    "myflowtyped": "1.0.0"
+  }
 }
diff --git a/tests/src/rules/named.js b/tests/src/rules/named.js
index 2364c74ede..e02cb455c1 100644
--- a/tests/src/rules/named.js
+++ b/tests/src/rules/named.js
@@ -1,4 +1,5 @@
 import { test, SYNTAX_CASES } from '../utils'
+import * as path from 'path'
 import { RuleTester } from 'eslint'
 
 import { CASE_SENSITIVE_FS } from 'eslint-module-utils/resolve'
@@ -12,6 +13,8 @@ function error(name, module) {
          , type: 'Identifier' }
 }
 
+const packageDirWithFlowTyped = path.join(__dirname, '../../files/with-flow-typed')
+
 ruleTester.run('named', rule, {
   valid: [
     test({ code: 'import "./malformed.js"' }),
@@ -80,6 +83,11 @@ ruleTester.run('named', rule, {
       code: 'import type { MyClass } from "./flowtypes"',
       'parser': 'babel-eslint',
     }),
+    test({
+      filename: packageDirWithFlowTyped + '/foo.js',
+      code: 'import type { MyType } from "myflowtyped"',
+      'parser': 'babel-eslint',
+    }),
 
     // TypeScript
     test({