From 7259b9fd4aa29ffb83acfffd14f55e6bee8c5d87 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Wed, 27 Jan 2016 14:00:33 -0800
Subject: [PATCH 1/2] Allow multiple 'this' property assignments in Salsa

Fixes issue #6645
---
 src/compiler/binder.ts                             |  3 ++-
 .../getJavaScriptSemanticDiagnostics23.ts          | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/getJavaScriptSemanticDiagnostics23.ts

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 88a1a62ce4..dbfe3a5195 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -1435,7 +1435,8 @@ namespace ts {
             // Declare a 'member' in case it turns out the container was an ES5 class
             if (container.kind === SyntaxKind.FunctionExpression || container.kind === SyntaxKind.FunctionDeclaration) {
                 container.symbol.members = container.symbol.members || {};
-                declareSymbol(container.symbol.members, container.symbol, node, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
+                // It's acceptable for multiple 'this' assignments of the same identifier to occur
+                declareSymbol(container.symbol.members, container.symbol, node, SymbolFlags.Property, SymbolFlags.PropertyExcludes & ~SymbolFlags.Property);
             }
         }
 
diff --git a/tests/cases/fourslash/getJavaScriptSemanticDiagnostics23.ts b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics23.ts
new file mode 100644
index 0000000000..2524e50e66
--- /dev/null
+++ b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics23.ts
@@ -0,0 +1,14 @@
+/// <reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+//// function Person(age) {
+////     if (age >= 18) {
+////         this.canVote = true;
+////     } else {
+////         this.canVote = false;
+////     }
+//// }
+
+verify.getSyntacticDiagnostics(`[]`);
+verify.getSemanticDiagnostics(`[]`);

From a4c6f666862d14e187bb7e09615fdfc0c92ab875 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Mon, 1 Feb 2016 20:59:37 -0800
Subject: [PATCH 2/2] Treat multiple prototype property assignments as union
 property declarations

---
 src/compiler/checker.ts                          |  2 +-
 .../getJavaScriptSemanticDiagnostics24.ts        | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/getJavaScriptSemanticDiagnostics24.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 61c05d7688..5cce092feb 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2827,7 +2827,7 @@ namespace ts {
                 }
                 // Handle module.exports = expr
                 if (declaration.kind === SyntaxKind.BinaryExpression) {
-                    return links.type = checkExpression((<BinaryExpression>declaration).right);
+                    return links.type = getUnionType(map(symbol.declarations, (decl: BinaryExpression) => checkExpressionCached(decl.right)));
                 }
                 if (declaration.kind === SyntaxKind.PropertyAccessExpression) {
                     // Declarations only exist for property access expressions for certain
diff --git a/tests/cases/fourslash/getJavaScriptSemanticDiagnostics24.ts b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics24.ts
new file mode 100644
index 0000000000..cf70f883e9
--- /dev/null
+++ b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics24.ts
@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+//// function Person(age) {
+////     if (age >= 18) {
+////         this.canVote = true;
+////     } else {
+////         this.canVote = 23;
+////     }
+//// }
+//// let x = new Person(100);
+//// x.canVote/**/;
+
+goTo.marker();
+verify.quickInfoIs('(property) Person.canVote: boolean | number');