From 8bd66a095d60724cd8ba94cba8b11fbd06bb4930 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Wed, 29 Nov 2017 11:36:25 -0800
Subject: [PATCH] JS Object literal assignments are declarations

Previously this only worked cross-file because it was a merge. Now it
works anywhere, and locally it is actually binding a new property on the
object literal symbol.
---
 src/compiler/binder.ts    |  4 ++--
 src/compiler/checker.ts   |  4 ++++
 src/compiler/utilities.ts | 19 ++++++++++++++++++-
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index bbfbef52ff7..b00282b8a62 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -2409,7 +2409,7 @@ namespace ts {
 
         function bindPropertyAssignment(functionName: __String, propertyAccess: PropertyAccessExpression, isPrototypeProperty: boolean) {
             const symbol = lookupSymbolForName(functionName);
-            let targetSymbol = symbol && isDeclarationOfFunctionOrClassExpression(symbol) ?
+            let targetSymbol = symbol && isDeclarationOfJavascriptExpression(symbol) ?
                 (symbol.valueDeclaration as VariableDeclaration).initializer.symbol :
                 symbol;
             Debug.assert(propertyAccess.parent.kind === SyntaxKind.BinaryExpression || propertyAccess.parent.kind === SyntaxKind.ExpressionStatement);
@@ -2432,7 +2432,7 @@ namespace ts {
                     targetSymbol = declareSymbol(container.locals, /*parent*/ undefined, identifier, SymbolFlags.Module, SymbolFlags.ValueModuleExcludes);
                 }
             }
-            if (!targetSymbol || !(targetSymbol.flags & (SymbolFlags.Function | SymbolFlags.Class | SymbolFlags.NamespaceModule))) {
+            if (!targetSymbol || !(targetSymbol.flags & (SymbolFlags.Function | SymbolFlags.Class | SymbolFlags.NamespaceModule | SymbolFlags.ObjectLiteral))) {
                 return;
             }
 
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 9ab2e2fbe27..8f0758a5fff 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -14431,6 +14431,10 @@ namespace ts {
             let hasComputedStringProperty = false;
             let hasComputedNumberProperty = false;
             const isInJSFile = isInJavaScriptFile(node);
+            if (isInJSFile && node.symbol && node.symbol.exports) {
+                mergeSymbolTable(propertiesTable, node.symbol.exports);
+                node.symbol.exports.forEach(symbol => propertiesArray.push(symbol));
+            }
 
             let offset = 0;
             for (let i = 0; i < node.properties.length; i++) {
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 80ca3bbdfad..386906ae297 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -1441,7 +1441,24 @@ namespace ts {
     export function isDeclarationOfFunctionOrClassExpression(s: Symbol) {
         if (s.valueDeclaration && s.valueDeclaration.kind === SyntaxKind.VariableDeclaration) {
             const declaration = s.valueDeclaration as VariableDeclaration;
-            return declaration.initializer && (declaration.initializer.kind === SyntaxKind.FunctionExpression || declaration.initializer.kind === SyntaxKind.ClassExpression);
+            return declaration.initializer &&
+                (declaration.initializer.kind === SyntaxKind.FunctionExpression || declaration.initializer.kind === SyntaxKind.ClassExpression);
+        }
+        return false;
+    }
+
+    /**
+     * Returns true if the node is a variable declaration whose initializer is a function or class expression, or an empty object literal.
+     * This function does not test if the node is in a JavaScript file or not.
+     */
+    export function isDeclarationOfJavascriptExpression(s: Symbol) {
+        if (s.valueDeclaration && s.valueDeclaration.kind === SyntaxKind.VariableDeclaration) {
+            const declaration = s.valueDeclaration as VariableDeclaration;
+            return declaration.initializer &&
+                (declaration.initializer.kind === SyntaxKind.FunctionExpression ||
+                 declaration.initializer.kind === SyntaxKind.ClassExpression ||
+                 (declaration.initializer.kind === SyntaxKind.ObjectLiteralExpression &&
+                  (declaration.initializer as ObjectLiteralExpression).properties.length === 0));
         }
         return false;
     }