From c8cd748e4807172871764d7726beddcb9deec250 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 21 Mar 2016 09:23:33 -0700
Subject: [PATCH] Handle JSDoc tags on 'this' properties

---
 src/compiler/checker.ts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 63d2afe72eb..49efcc7dc0b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2937,6 +2937,14 @@ namespace ts {
                 }
                 // Handle module.exports = expr
                 if (declaration.kind === SyntaxKind.BinaryExpression) {
+                    // Use JS Doc type if present on parent expression statement
+                    if (declaration.flags & NodeFlags.JavaScriptFile) {
+                        const typeTag = getJSDocTypeTag(declaration.parent);
+                        if (typeTag && typeTag.typeExpression) {
+                            return links.type = getTypeFromTypeNode(typeTag.typeExpression.type);
+                        }
+                    }
+
                     return links.type = getUnionType(map(symbol.declarations, (decl: BinaryExpression) => checkExpressionCached(decl.right)));
                 }
                 if (declaration.kind === SyntaxKind.PropertyAccessExpression) {