From 6a2938deaaceb730e04b6ba9526bb5e48d4396d0 Mon Sep 17 00:00:00 2001
From: Henry Zhu <hi@henryzoo.com>
Date: Wed, 3 Jun 2015 17:11:28 -0400
Subject: [PATCH] Merge pull request babel/babel-eslint#118 from
 hzoo/poly-types

add flow exceptions for polymorphic types (<A>) - Ref babel/babel-eslint#109
---
 eslint/babel-eslint-parser/index.js           |  4 ++++
 .../test/non-regression.js                    | 20 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/eslint/babel-eslint-parser/index.js b/eslint/babel-eslint-parser/index.js
index cd28c76545..3c764c99f8 100644
--- a/eslint/babel-eslint-parser/index.js
+++ b/eslint/babel-eslint-parser/index.js
@@ -163,6 +163,10 @@ function monkeypatch() {
     if (node.typeAnnotation) {
       visitTypeAnnotation.call(this, node.typeAnnotation);
     } else if (node.type === "Identifier") {
+      // exception for polymorphic types: <T>, <A>, etc
+      if (node.name.length === 1 && node.name === node.name.toUpperCase()) {
+        return;
+      }
       this.visit(node);
     } else {
       visitTypeAnnotation.call(this, node);
diff --git a/eslint/babel-eslint-parser/test/non-regression.js b/eslint/babel-eslint-parser/test/non-regression.js
index 2a837f779c..598498afab 100644
--- a/eslint/babel-eslint-parser/test/non-regression.js
+++ b/eslint/babel-eslint-parser/test/non-regression.js
@@ -296,6 +296,26 @@ describe("verify", function () {
       );
     });
 
+    it("polymorphpic types #109", function () {
+      verifyAndAssertMessages([
+          "export default function groupByEveryN<T>(array: Array<T>, n: number): Array<Array<?T>> {}"
+        ].join("\n"),
+        { "no-unused-vars": 1, "no-undef": 1 },
+        []
+      );
+    });
+
+    it("types definition from import", function () {
+      verifyAndAssertMessages([
+          "import type Promise from 'bluebird';",
+          "type Operation = () => Promise;",
+          "x: Operation;"
+        ].join("\n"),
+        { "no-unused-vars": 1, "no-undef": 1 },
+        []
+      );
+    });
+
     it("1", function () {
       verifyAndAssertMessages(
         [