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.

Author: tf

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'

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;
+}

tests/files/with-flow-typed/node_modules/myflowtyped/index.js

@@ -1,3 +1,5 @@
 {
-  "dependencies": {}
+  "dependencies": {
+    "myflowtyped": "1.0.0"
+  }
 }

tests/files/with-flow-typed/node_modules/myflowtyped/package.json

@@ -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({