From fcd22f553c2037a9eb3c92e8d5d8af4bb7b6bc31 Mon Sep 17 00:00:00 2001
From: Henry Zhu <hi@henryzoo.com>
Date: Tue, 16 Jun 2015 21:47:17 -0400
Subject: [PATCH] support flow declarations correctly, lint - fixes #132

---
 acorn-to-esprima.js    | 11 +----------
 index.js               | 17 +++++++++++++++--
 test/non-regression.js | 16 ++++++++++++++--
 3 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/acorn-to-esprima.js b/acorn-to-esprima.js
index 9dfdfffa..7809f04a 100644
--- a/acorn-to-esprima.js
+++ b/acorn-to-esprima.js
@@ -183,7 +183,7 @@ var astTransformVisitor = {
       return node.argument;
     }
 
-    // prevent "no-undef"
+    // flow: prevent "no-undef"
     // for "Component" in: "let x: React.Component"
     if (this.isQualifiedTypeIdentifier()) {
       delete node.id;
@@ -201,15 +201,6 @@ var astTransformVisitor = {
       delete node.name;
     }
 
-    // flow
-
-    if (this.isDeclareModule() ||
-        this.isDeclareClass() ||
-        this.isDeclareFunction() ||
-        this.isDeclareVariable()) {
-      return this.dangerouslyRemove();
-    }
-
     // modules
 
     if (this.isImportDeclaration()) {
diff --git a/index.js b/index.js
index e78025c0..f69d9f0a 100644
--- a/index.js
+++ b/index.js
@@ -178,7 +178,7 @@ function monkeypatch() {
     }
     scope.__define = function() {
       return parentScope.__define.apply(parentScope, arguments);
-    }
+    };
     return scope;
   }
 
@@ -250,7 +250,7 @@ function monkeypatch() {
         if (typeAnnotation) {
           checkIdentifierOrVisit.call(this, typeAnnotation);
         }
-        if (id.type === 'ObjectPattern') {
+        if (id.type === "ObjectPattern") {
           for (var j = 0; j < id.properties.length; j++) {
             this.visit(id.properties[j]);
           }
@@ -304,6 +304,19 @@ function monkeypatch() {
       this.visit(node.right);
     }
   };
+
+  referencer.prototype.DeclareModule =
+  referencer.prototype.DeclareFunction =
+  referencer.prototype.DeclareVariable =
+  referencer.prototype.DeclareClass = function(node) {
+    var typeParamScope;
+    if (node.typeParameters) {
+      typeParamScope = nestTypeParamScope(this.scopeManager, node);
+    }
+    if (typeParamScope) {
+      this.close(node);
+    }
+  };
 }
 
 exports.attachComments = function (ast, comments, tokens) {
diff --git a/test/non-regression.js b/test/non-regression.js
index de0bfbf6..4b4665f2 100644
--- a/test/non-regression.js
+++ b/test/non-regression.js
@@ -356,7 +356,7 @@ describe("verify", function () {
           "var b: T = 1; b;"
         ].join("\n"),
         { "no-unused-vars": 1, "no-undef": 1 },
-        [ '1:20 T is defined but never used no-unused-vars',
+        [ "1:20 T is defined but never used no-unused-vars",
           '3:7 "T" is not defined. no-undef' ]
       );
     });
@@ -371,6 +371,18 @@ describe("verify", function () {
       );
     });
 
+    it("support declarations #132", function () {
+      verifyAndAssertMessages([
+          "declare class A { static () : number }",
+          "declare module B { declare var x: number; }",
+          "declare function foo<T>(): void;",
+          "declare var bar"
+        ].join("\n"),
+        { "no-undef": 1, "no-unused-vars": 1 },
+        []
+      );
+    });
+
     it("1", function () {
       verifyAndAssertMessages(
         [
@@ -1133,6 +1145,6 @@ describe("verify", function () {
       "var originalObject = {}; var {field1, field2, ...clone} = originalObject;",
       { "no-undef": 1, "no-unused-vars": 1 },
       []
-    )
+    );
   });
 });