From 854c124a10773ef069bc065a0bbd24438c434171 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Thu, 5 Apr 2018 16:33:07 -0700
Subject: [PATCH 1/5] Combining symbol and removing error done but messy

---
 src/compiler/checker.ts                       | 45 ++++++++++++++++---
 ...oduleExportWithExportPropertyAssignment.ts | 12 +++++
 2 files changed, 51 insertions(+), 6 deletions(-)
 create mode 100644 tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 34e5000790add..1a4a6a8248cd1 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2096,9 +2096,15 @@ namespace ts {
                         const moduleName = (namespace.valueDeclaration.initializer as CallExpression).arguments[0] as StringLiteral;
                         const moduleSym = resolveExternalModuleName(moduleName, moduleName);
                         if (moduleSym) {
-                            const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
-                            if (resolvedModuleSymbol) {
-                                namespace = resolvedModuleSymbol;
+                            if (moduleSym.exports.has(InternalSymbolName.ExportEquals as __String) && moduleSym.exports.size > 1) {
+                                Debug.assert(!!(moduleSym.valueDeclaration as SourceFile).commonJsModuleIndicator);
+                                namespace = combineCommonJsSymbol(moduleSym);
+                            }
+                            else {
+                                const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
+                                if (resolvedModuleSymbol) {
+                                    namespace = resolvedModuleSymbol;
+                                }
                             }
                         }
                     }
@@ -4350,7 +4356,8 @@ namespace ts {
                     return unknownType;
                 }
 
-                if (isPropertyAccessExpression(expression.left) && expression.left.expression.kind === SyntaxKind.ThisKeyword) {
+                const special = getSpecialPropertyAssignmentKind(expression);
+                if (special === SpecialPropertyAssignmentKind.ThisProperty) {
                     const thisContainer = getThisContainer(expression, /*includeArrowFunctions*/ false);
                     // Properties defined in a constructor (or javascript constructor function) don't get undefined added.
                     // Function expressions that are assigned to the prototype count as methods.
@@ -4380,7 +4387,17 @@ namespace ts {
                 }
                 else if (!jsDocType) {
                     // If we don't have an explicit JSDoc type, get the type from the expression.
-                    const type = getWidenedLiteralType(checkExpressionCached(expression.right));
+                    let type = getWidenedLiteralType(checkExpressionCached(expression.right));
+
+                    if (getObjectFlags(type) & ObjectFlags.Anonymous &&
+                        special === SpecialPropertyAssignmentKind.ModuleExports &&
+                        symbol.escapedName === InternalSymbolName.ExportEquals) {
+                        const o = resolveStructuredTypeMembers(type as AnonymousType);
+                        const members = createSymbolTable();
+                        copyEntries(o.members, members);
+                        copyEntries(symbol.exports, members);
+                        type = createAnonymousType(symbol, members, o.callSignatures, o.constructSignatures, o.stringIndexInfo, o.numberIndexInfo);
+                    }
                     let anyedType = type;
                     if (isEmptyArrayLiteralType(type)) {
                         anyedType = anyArrayType;
@@ -6992,6 +7009,10 @@ namespace ts {
         function resolveExternalModuleTypeByLiteral(name: StringLiteral) {
             const moduleSym = resolveExternalModuleName(name, name);
             if (moduleSym) {
+                if (moduleSym.exports.has(InternalSymbolName.ExportEquals as __String) && moduleSym.exports.size > 1) {
+                    Debug.assert(!!(moduleSym.valueDeclaration as SourceFile).commonJsModuleIndicator);
+                    return getTypeOfSymbol(combineCommonJsSymbol(moduleSym));
+                }
                 const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
                 if (resolvedModuleSymbol) {
                     return getTypeOfSymbol(resolvedModuleSymbol);
@@ -7001,6 +7022,18 @@ namespace ts {
             return anyType;
         }
 
+        function combineCommonJsSymbol(moduleSym: Symbol): Symbol {
+            const combined = cloneSymbol(moduleSym.exports.get(InternalSymbolName.ExportEquals));
+            moduleSym.exports.forEach((s,name) => {
+                if (name === InternalSymbolName.ExportEquals) return;
+                if (!combined.exports.has(name) || combined.exports.get(name).valueDeclaration.pos > s.valueDeclaration.pos) {
+                    combined.exports.set(name, s);
+                }
+            });
+            return combined;
+
+        }
+
         function getThisTypeOfSignature(signature: Signature): Type | undefined {
             if (signature.thisParameter) {
                 return getTypeOfSymbol(signature.thisParameter);
@@ -24568,7 +24601,7 @@ namespace ts {
                 const exportEqualsSymbol = moduleSymbol.exports.get("export=" as __String);
                 if (exportEqualsSymbol && hasExportedMembers(moduleSymbol)) {
                     const declaration = getDeclarationOfAliasSymbol(exportEqualsSymbol) || exportEqualsSymbol.valueDeclaration;
-                    if (!isTopLevelInExternalModuleAugmentation(declaration)) {
+                    if (!isTopLevelInExternalModuleAugmentation(declaration) && !isInJavaScriptFile(declaration)) {
                         error(declaration, Diagnostics.An_export_assignment_cannot_be_used_in_a_module_with_other_exported_elements);
                     }
                 }
diff --git a/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts
new file mode 100644
index 0000000000000..9486f238e74e4
--- /dev/null
+++ b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts
@@ -0,0 +1,12 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @Filename: mod1.js
+// TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+module.exports = function () { }
+module.exports.f = function () { }
+
+// @Filename: a.js
+var mod1 = require('./mod1')
+mod1()
+mod1.f()

From 8b67c9b799bb322f4e9cf49654404e0c0a7ee52d Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Thu, 5 Apr 2018 16:38:31 -0700
Subject: [PATCH 2/5] Small fix + add new test baselines

All other tests are unchanged
---
 src/compiler/checker.ts                       |  2 +-
 ...ortWithExportPropertyAssignment.errors.txt | 21 +++++++++++
 ...ExportWithExportPropertyAssignment.symbols | 23 ++++++++++++
 ...leExportWithExportPropertyAssignment.types | 35 +++++++++++++++++++
 4 files changed, 80 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment.types

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1a4a6a8248cd1..5cf682b5b6c95 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -4396,7 +4396,7 @@ namespace ts {
                         const members = createSymbolTable();
                         copyEntries(o.members, members);
                         copyEntries(symbol.exports, members);
-                        type = createAnonymousType(symbol, members, o.callSignatures, o.constructSignatures, o.stringIndexInfo, o.numberIndexInfo);
+                        type = createAnonymousType(o.symbol, members, o.callSignatures, o.constructSignatures, o.stringIndexInfo, o.numberIndexInfo);
                     }
                     let anyedType = type;
                     if (isEmptyArrayLiteralType(type)) {
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt
new file mode 100644
index 0000000000000..63c13c96c136b
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt
@@ -0,0 +1,21 @@
+tests/cases/conformance/salsa/a.js(1,12): error TS2304: Cannot find name 'require'.
+tests/cases/conformance/salsa/mod1.js(2,1): error TS2304: Cannot find name 'module'.
+tests/cases/conformance/salsa/mod1.js(3,1): error TS2304: Cannot find name 'module'.
+
+
+==== tests/cases/conformance/salsa/a.js (1 errors) ====
+    var mod1 = require('./mod1')
+               ~~~~~~~
+!!! error TS2304: Cannot find name 'require'.
+    mod1()
+    mod1.f()
+    
+==== tests/cases/conformance/salsa/mod1.js (2 errors) ====
+    // TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+    module.exports = function () { }
+    ~~~~~~
+!!! error TS2304: Cannot find name 'module'.
+    module.exports.f = function () { }
+    ~~~~~~
+!!! error TS2304: Cannot find name 'module'.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols
new file mode 100644
index 0000000000000..77fb9fd209745
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols
@@ -0,0 +1,23 @@
+=== tests/cases/conformance/salsa/a.js ===
+var mod1 = require('./mod1')
+>mod1 : Symbol(mod1, Decl(a.js, 0, 3))
+>'./mod1' : Symbol("tests/cases/conformance/salsa/mod1", Decl(mod1.js, 0, 0))
+
+mod1()
+>mod1 : Symbol(mod1, Decl(a.js, 0, 3))
+
+mod1.f()
+>mod1.f : Symbol(f, Decl(mod1.js, 1, 32))
+>mod1 : Symbol(mod1, Decl(a.js, 0, 3))
+>f : Symbol(f, Decl(mod1.js, 1, 32))
+
+=== tests/cases/conformance/salsa/mod1.js ===
+// TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+module.exports = function () { }
+>module : Symbol(export=, Decl(mod1.js, 0, 0))
+>exports : Symbol(export=, Decl(mod1.js, 0, 0))
+
+module.exports.f = function () { }
+>module.exports : Symbol(f, Decl(mod1.js, 1, 32))
+>f : Symbol(f, Decl(mod1.js, 1, 32))
+
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types
new file mode 100644
index 0000000000000..d1657107fdfda
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types
@@ -0,0 +1,35 @@
+=== tests/cases/conformance/salsa/a.js ===
+var mod1 = require('./mod1')
+>mod1 : { (): void; f: () => void; }
+>require('./mod1') : { (): void; f: () => void; }
+>require : any
+>'./mod1' : "./mod1"
+
+mod1()
+>mod1() : void
+>mod1 : { (): void; f: () => void; }
+
+mod1.f()
+>mod1.f() : void
+>mod1.f : () => void
+>mod1 : { (): void; f: () => void; }
+>f : () => void
+
+=== tests/cases/conformance/salsa/mod1.js ===
+// TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+module.exports = function () { }
+>module.exports = function () { } : () => void
+>module.exports : any
+>module : any
+>exports : any
+>function () { } : () => void
+
+module.exports.f = function () { }
+>module.exports.f = function () { } : () => void
+>module.exports.f : any
+>module.exports : any
+>module : any
+>exports : any
+>f : any
+>function () { } : () => void
+

From 571e9350cbbbb5364f23172f81cf48c73a74a064 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Fri, 6 Apr 2018 10:44:21 -0700
Subject: [PATCH 3/5] Union conflicting assignment types+better names

---
 src/compiler/checker.ts | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 5cf682b5b6c95..a33421c946dd5 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2098,7 +2098,7 @@ namespace ts {
                         if (moduleSym) {
                             if (moduleSym.exports.has(InternalSymbolName.ExportEquals as __String) && moduleSym.exports.size > 1) {
                                 Debug.assert(!!(moduleSym.valueDeclaration as SourceFile).commonJsModuleIndicator);
-                                namespace = combineCommonJsSymbol(moduleSym);
+                                namespace = mergeCommonJsExportEquals(moduleSym);
                             }
                             else {
                                 const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
@@ -4392,11 +4392,27 @@ namespace ts {
                     if (getObjectFlags(type) & ObjectFlags.Anonymous &&
                         special === SpecialPropertyAssignmentKind.ModuleExports &&
                         symbol.escapedName === InternalSymbolName.ExportEquals) {
-                        const o = resolveStructuredTypeMembers(type as AnonymousType);
+                        const exportedType = resolveStructuredTypeMembers(type as AnonymousType);
                         const members = createSymbolTable();
-                        copyEntries(o.members, members);
-                        copyEntries(symbol.exports, members);
-                        type = createAnonymousType(o.symbol, members, o.callSignatures, o.constructSignatures, o.stringIndexInfo, o.numberIndexInfo);
+                        copyEntries(exportedType.members, members);
+                        symbol.exports.forEach((s, name) => {
+                            if (members.has(name)) {
+                                const exportedMember = exportedType.members.get(name);
+                                const union = createSymbol(s.flags | exportedMember.flags, name);
+                                union.type = getUnionType([getTypeOfSymbol(s), getTypeOfSymbol(exportedMember)]);
+                                members.set(name, union);
+                            }
+                            else {
+                                members.set(name, s);
+                            }
+                        });
+                        type = createAnonymousType(
+                            exportedType.symbol,
+                            members,
+                            exportedType.callSignatures,
+                            exportedType.constructSignatures,
+                            exportedType.stringIndexInfo,
+                            exportedType.numberIndexInfo);
                     }
                     let anyedType = type;
                     if (isEmptyArrayLiteralType(type)) {
@@ -7011,7 +7027,7 @@ namespace ts {
             if (moduleSym) {
                 if (moduleSym.exports.has(InternalSymbolName.ExportEquals as __String) && moduleSym.exports.size > 1) {
                     Debug.assert(!!(moduleSym.valueDeclaration as SourceFile).commonJsModuleIndicator);
-                    return getTypeOfSymbol(combineCommonJsSymbol(moduleSym));
+                    return getTypeOfSymbol(mergeCommonJsExportEquals(moduleSym));
                 }
                 const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
                 if (resolvedModuleSymbol) {
@@ -7022,11 +7038,11 @@ namespace ts {
             return anyType;
         }
 
-        function combineCommonJsSymbol(moduleSym: Symbol): Symbol {
+        function mergeCommonJsExportEquals(moduleSym: Symbol): Symbol {
             const combined = cloneSymbol(moduleSym.exports.get(InternalSymbolName.ExportEquals));
-            moduleSym.exports.forEach((s,name) => {
+            moduleSym.exports.forEach((s, name) => {
                 if (name === InternalSymbolName.ExportEquals) return;
-                if (!combined.exports.has(name) || combined.exports.get(name).valueDeclaration.pos > s.valueDeclaration.pos) {
+                if (!combined.exports.has(name)) {
                     combined.exports.set(name, s);
                 }
             });

From 6203ec7ec1223a60f50f28adec6fc3ca8b200e94 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Fri, 6 Apr 2018 10:44:48 -0700
Subject: [PATCH 4/5] Add tests and update baselines

---
 ...ortWithExportPropertyAssignment.errors.txt |  25 ++--
 ...ExportWithExportPropertyAssignment.symbols |  28 ++++-
 ...leExportWithExportPropertyAssignment.types |  40 +++---
 ...rtWithExportPropertyAssignment2.errors.txt |  19 +++
 ...xportWithExportPropertyAssignment2.symbols |  37 ++++++
 ...eExportWithExportPropertyAssignment2.types |  48 ++++++++
 ...rtWithExportPropertyAssignment3.errors.txt |  34 ++++++
 ...xportWithExportPropertyAssignment3.symbols |  74 +++++++++++
 ...eExportWithExportPropertyAssignment3.types |  96 +++++++++++++++
 ...rtWithExportPropertyAssignment4.errors.txt |  36 ++++++
 ...xportWithExportPropertyAssignment4.symbols |  87 +++++++++++++
 ...eExportWithExportPropertyAssignment4.types | 115 ++++++++++++++++++
 ...oduleExportWithExportPropertyAssignment.ts |  11 +-
 ...duleExportWithExportPropertyAssignment2.ts |  16 +++
 ...duleExportWithExportPropertyAssignment3.ts |  24 ++++
 ...duleExportWithExportPropertyAssignment4.ts |  26 ++++
 16 files changed, 680 insertions(+), 36 deletions(-)
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment2.errors.txt
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment2.symbols
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment2.types
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment3.errors.txt
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment3.symbols
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment3.types
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment4.errors.txt
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment4.symbols
 create mode 100644 tests/baselines/reference/moduleExportWithExportPropertyAssignment4.types
 create mode 100644 tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment2.ts
 create mode 100644 tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment3.ts
 create mode 100644 tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment4.ts

diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt
index 63c13c96c136b..aab334e77f38c 100644
--- a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.errors.txt
@@ -1,21 +1,20 @@
-tests/cases/conformance/salsa/a.js(1,12): error TS2304: Cannot find name 'require'.
-tests/cases/conformance/salsa/mod1.js(2,1): error TS2304: Cannot find name 'module'.
-tests/cases/conformance/salsa/mod1.js(3,1): error TS2304: Cannot find name 'module'.
+tests/cases/conformance/salsa/a.js(4,1): error TS2554: Expected 1 arguments, but got 0.
 
 
 ==== tests/cases/conformance/salsa/a.js (1 errors) ====
+    /// <reference path='./requires.d.ts' />
     var mod1 = require('./mod1')
-               ~~~~~~~
-!!! error TS2304: Cannot find name 'require'.
     mod1()
-    mod1.f()
+    mod1.f() // error, not enough arguments
+    ~~~~~~~~
+!!! error TS2554: Expected 1 arguments, but got 0.
     
-==== tests/cases/conformance/salsa/mod1.js (2 errors) ====
-    // TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+==== tests/cases/conformance/salsa/requires.d.ts (0 errors) ====
+    declare var module: { exports: any };
+    declare function require(name: string): any;
+==== tests/cases/conformance/salsa/mod1.js (0 errors) ====
+    /// <reference path='./requires.d.ts' />
     module.exports = function () { }
-    ~~~~~~
-!!! error TS2304: Cannot find name 'module'.
-    module.exports.f = function () { }
-    ~~~~~~
-!!! error TS2304: Cannot find name 'module'.
+    /** @param {number} a */
+    module.exports.f = function (a) { }
     
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols
index 77fb9fd209745..c5120a80571e3 100644
--- a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.symbols
@@ -1,23 +1,39 @@
 === tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
 var mod1 = require('./mod1')
->mod1 : Symbol(mod1, Decl(a.js, 0, 3))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
 >'./mod1' : Symbol("tests/cases/conformance/salsa/mod1", Decl(mod1.js, 0, 0))
 
 mod1()
->mod1 : Symbol(mod1, Decl(a.js, 0, 3))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
 
-mod1.f()
+mod1.f() // error, not enough arguments
 >mod1.f : Symbol(f, Decl(mod1.js, 1, 32))
->mod1 : Symbol(mod1, Decl(a.js, 0, 3))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
 >f : Symbol(f, Decl(mod1.js, 1, 32))
 
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+
+declare function require(name: string): any;
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>name : Symbol(name, Decl(requires.d.ts, 1, 25))
+
 === tests/cases/conformance/salsa/mod1.js ===
-// TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+/// <reference path='./requires.d.ts' />
 module.exports = function () { }
+>module.exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
 >module : Symbol(export=, Decl(mod1.js, 0, 0))
 >exports : Symbol(export=, Decl(mod1.js, 0, 0))
 
-module.exports.f = function () { }
+/** @param {number} a */
+module.exports.f = function (a) { }
 >module.exports : Symbol(f, Decl(mod1.js, 1, 32))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
 >f : Symbol(f, Decl(mod1.js, 1, 32))
+>a : Symbol(a, Decl(mod1.js, 3, 29))
 
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types
index d1657107fdfda..b7170842c1f39 100644
--- a/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment.types
@@ -1,35 +1,47 @@
 === tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
 var mod1 = require('./mod1')
->mod1 : { (): void; f: () => void; }
->require('./mod1') : { (): void; f: () => void; }
->require : any
+>mod1 : { (): void; f: (a: number) => void; }
+>require('./mod1') : { (): void; f: (a: number) => void; }
+>require : (name: string) => any
 >'./mod1' : "./mod1"
 
 mod1()
 >mod1() : void
->mod1 : { (): void; f: () => void; }
+>mod1 : { (): void; f: (a: number) => void; }
 
-mod1.f()
+mod1.f() // error, not enough arguments
 >mod1.f() : void
->mod1.f : () => void
->mod1 : { (): void; f: () => void; }
->f : () => void
+>mod1.f : (a: number) => void
+>mod1 : { (): void; f: (a: number) => void; }
+>f : (a: number) => void
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : { exports: any; }
+>exports : any
+
+declare function require(name: string): any;
+>require : (name: string) => any
+>name : string
 
 === tests/cases/conformance/salsa/mod1.js ===
-// TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+/// <reference path='./requires.d.ts' />
 module.exports = function () { }
 >module.exports = function () { } : () => void
 >module.exports : any
->module : any
+>module : { exports: any; }
 >exports : any
 >function () { } : () => void
 
-module.exports.f = function () { }
->module.exports.f = function () { } : () => void
+/** @param {number} a */
+module.exports.f = function (a) { }
+>module.exports.f = function (a) { } : (a: number) => void
 >module.exports.f : any
 >module.exports : any
->module : any
+>module : { exports: any; }
 >exports : any
 >f : any
->function () { } : () => void
+>function (a) { } : (a: number) => void
+>a : number
 
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.errors.txt b/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.errors.txt
new file mode 100644
index 0000000000000..66cb517a25be7
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.errors.txt
@@ -0,0 +1,19 @@
+tests/cases/conformance/salsa/a.js(4,6): error TS2339: Property 'f' does not exist on type 'number'.
+
+
+==== tests/cases/conformance/salsa/a.js (1 errors) ====
+    /// <reference path='./requires.d.ts' />
+    var mod1 = require('./mod1')
+    mod1.toFixed(12)
+    mod1.f() // error, 'f' is not a property on 'number'
+         ~
+!!! error TS2339: Property 'f' does not exist on type 'number'.
+    
+==== tests/cases/conformance/salsa/requires.d.ts (0 errors) ====
+    declare var module: { exports: any };
+    declare function require(name: string): any;
+==== tests/cases/conformance/salsa/mod1.js (0 errors) ====
+    /// <reference path='./requires.d.ts' />
+    module.exports = 1
+    module.exports.f = function () { }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.symbols b/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.symbols
new file mode 100644
index 0000000000000..c9a09bb6a8b99
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.symbols
@@ -0,0 +1,37 @@
+=== tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>'./mod1' : Symbol("tests/cases/conformance/salsa/mod1", Decl(mod1.js, 0, 0))
+
+mod1.toFixed(12)
+>mod1.toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
+
+mod1.f() // error, 'f' is not a property on 'number'
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+
+declare function require(name: string): any;
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>name : Symbol(name, Decl(requires.d.ts, 1, 25))
+
+=== tests/cases/conformance/salsa/mod1.js ===
+/// <reference path='./requires.d.ts' />
+module.exports = 1
+>module.exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>module : Symbol(export=, Decl(mod1.js, 0, 0))
+>exports : Symbol(export=, Decl(mod1.js, 0, 0))
+
+module.exports.f = function () { }
+>module.exports : Symbol(f, Decl(mod1.js, 1, 18))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>f : Symbol(f, Decl(mod1.js, 1, 18))
+
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.types b/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.types
new file mode 100644
index 0000000000000..8af94a05fa5c6
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment2.types
@@ -0,0 +1,48 @@
+=== tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+>mod1 : number
+>require('./mod1') : number
+>require : (name: string) => any
+>'./mod1' : "./mod1"
+
+mod1.toFixed(12)
+>mod1.toFixed(12) : string
+>mod1.toFixed : (fractionDigits?: number) => string
+>mod1 : number
+>toFixed : (fractionDigits?: number) => string
+>12 : 12
+
+mod1.f() // error, 'f' is not a property on 'number'
+>mod1.f() : any
+>mod1.f : any
+>mod1 : number
+>f : any
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : { exports: any; }
+>exports : any
+
+declare function require(name: string): any;
+>require : (name: string) => any
+>name : string
+
+=== tests/cases/conformance/salsa/mod1.js ===
+/// <reference path='./requires.d.ts' />
+module.exports = 1
+>module.exports = 1 : 1
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>1 : 1
+
+module.exports.f = function () { }
+>module.exports.f = function () { } : () => void
+>module.exports.f : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>f : any
+>function () { } : () => void
+
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.errors.txt b/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.errors.txt
new file mode 100644
index 0000000000000..bbaed77a0f90c
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.errors.txt
@@ -0,0 +1,34 @@
+tests/cases/conformance/salsa/a.js(4,17): error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+  Property 'toFixed' does not exist on type 'string'.
+tests/cases/conformance/salsa/a.js(5,16): error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+  Property 'toFixed' does not exist on type 'string'.
+
+
+==== tests/cases/conformance/salsa/a.js (2 errors) ====
+    /// <reference path='./requires.d.ts' />
+    var mod1 = require('./mod1')
+    mod1.justExport.toFixed()
+    mod1.bothBefore.toFixed() // error, 'toFixed' not on 'string | number'
+                    ~~~~~~~
+!!! error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+!!! error TS2339:   Property 'toFixed' does not exist on type 'string'.
+    mod1.bothAfter.toFixed() // error, 'toFixed' not on 'string | number'
+                   ~~~~~~~
+!!! error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+!!! error TS2339:   Property 'toFixed' does not exist on type 'string'.
+    mod1.justProperty.length
+    
+==== tests/cases/conformance/salsa/requires.d.ts (0 errors) ====
+    declare var module: { exports: any };
+    declare function require(name: string): any;
+==== tests/cases/conformance/salsa/mod1.js (0 errors) ====
+    /// <reference path='./requires.d.ts' />
+    module.exports.bothBefore = 'string'
+    module.exports = {
+        justExport: 1,
+        bothBefore: 2,
+        bothAfter: 3,
+    }
+    module.exports.bothAfter = 'string'
+    module.exports.justProperty = 'string'
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.symbols b/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.symbols
new file mode 100644
index 0000000000000..a84080cc998d8
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.symbols
@@ -0,0 +1,74 @@
+=== tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>'./mod1' : Symbol("tests/cases/conformance/salsa/mod1", Decl(mod1.js, 0, 0))
+
+mod1.justExport.toFixed()
+>mod1.justExport.toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
+>mod1.justExport : Symbol(justExport, Decl(mod1.js, 2, 18))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>justExport : Symbol(justExport, Decl(mod1.js, 2, 18))
+>toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
+
+mod1.bothBefore.toFixed() // error, 'toFixed' not on 'string | number'
+>mod1.bothBefore : Symbol(bothBefore)
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>bothBefore : Symbol(bothBefore)
+
+mod1.bothAfter.toFixed() // error, 'toFixed' not on 'string | number'
+>mod1.bothAfter : Symbol(bothAfter)
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>bothAfter : Symbol(bothAfter)
+
+mod1.justProperty.length
+>mod1.justProperty.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>mod1.justProperty : Symbol(justProperty, Decl(mod1.js, 7, 35))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>justProperty : Symbol(justProperty, Decl(mod1.js, 7, 35))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+
+declare function require(name: string): any;
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>name : Symbol(name, Decl(requires.d.ts, 1, 25))
+
+=== tests/cases/conformance/salsa/mod1.js ===
+/// <reference path='./requires.d.ts' />
+module.exports.bothBefore = 'string'
+>module.exports : Symbol(bothBefore, Decl(mod1.js, 0, 0))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>bothBefore : Symbol(bothBefore, Decl(mod1.js, 0, 0))
+
+module.exports = {
+>module.exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>module : Symbol(export=, Decl(mod1.js, 1, 36))
+>exports : Symbol(export=, Decl(mod1.js, 1, 36))
+
+    justExport: 1,
+>justExport : Symbol(justExport, Decl(mod1.js, 2, 18))
+
+    bothBefore: 2,
+>bothBefore : Symbol(bothBefore, Decl(mod1.js, 3, 18))
+
+    bothAfter: 3,
+>bothAfter : Symbol(bothAfter, Decl(mod1.js, 4, 18))
+}
+module.exports.bothAfter = 'string'
+>module.exports : Symbol(bothAfter, Decl(mod1.js, 6, 1))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>bothAfter : Symbol(bothAfter, Decl(mod1.js, 6, 1))
+
+module.exports.justProperty = 'string'
+>module.exports : Symbol(justProperty, Decl(mod1.js, 7, 35))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>justProperty : Symbol(justProperty, Decl(mod1.js, 7, 35))
+
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.types b/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.types
new file mode 100644
index 0000000000000..4d14bf647fd2c
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment3.types
@@ -0,0 +1,96 @@
+=== tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+>mod1 : { [x: string]: any; justExport: number; bothBefore: string | number; bothAfter: string | number; justProperty: string; }
+>require('./mod1') : { [x: string]: any; justExport: number; bothBefore: string | number; bothAfter: string | number; justProperty: string; }
+>require : (name: string) => any
+>'./mod1' : "./mod1"
+
+mod1.justExport.toFixed()
+>mod1.justExport.toFixed() : string
+>mod1.justExport.toFixed : (fractionDigits?: number) => string
+>mod1.justExport : number
+>mod1 : { [x: string]: any; justExport: number; bothBefore: string | number; bothAfter: string | number; justProperty: string; }
+>justExport : number
+>toFixed : (fractionDigits?: number) => string
+
+mod1.bothBefore.toFixed() // error, 'toFixed' not on 'string | number'
+>mod1.bothBefore.toFixed() : any
+>mod1.bothBefore.toFixed : any
+>mod1.bothBefore : string | number
+>mod1 : { [x: string]: any; justExport: number; bothBefore: string | number; bothAfter: string | number; justProperty: string; }
+>bothBefore : string | number
+>toFixed : any
+
+mod1.bothAfter.toFixed() // error, 'toFixed' not on 'string | number'
+>mod1.bothAfter.toFixed() : any
+>mod1.bothAfter.toFixed : any
+>mod1.bothAfter : string | number
+>mod1 : { [x: string]: any; justExport: number; bothBefore: string | number; bothAfter: string | number; justProperty: string; }
+>bothAfter : string | number
+>toFixed : any
+
+mod1.justProperty.length
+>mod1.justProperty.length : number
+>mod1.justProperty : string
+>mod1 : { [x: string]: any; justExport: number; bothBefore: string | number; bothAfter: string | number; justProperty: string; }
+>justProperty : string
+>length : number
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : { exports: any; }
+>exports : any
+
+declare function require(name: string): any;
+>require : (name: string) => any
+>name : string
+
+=== tests/cases/conformance/salsa/mod1.js ===
+/// <reference path='./requires.d.ts' />
+module.exports.bothBefore = 'string'
+>module.exports.bothBefore = 'string' : "string"
+>module.exports.bothBefore : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>bothBefore : any
+>'string' : "string"
+
+module.exports = {
+>module.exports = {    justExport: 1,    bothBefore: 2,    bothAfter: 3,} : { [x: string]: any; justExport: number; bothBefore: number; bothAfter: number; }
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>{    justExport: 1,    bothBefore: 2,    bothAfter: 3,} : { [x: string]: any; justExport: number; bothBefore: number; bothAfter: number; }
+
+    justExport: 1,
+>justExport : number
+>1 : 1
+
+    bothBefore: 2,
+>bothBefore : number
+>2 : 2
+
+    bothAfter: 3,
+>bothAfter : number
+>3 : 3
+}
+module.exports.bothAfter = 'string'
+>module.exports.bothAfter = 'string' : "string"
+>module.exports.bothAfter : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>bothAfter : any
+>'string' : "string"
+
+module.exports.justProperty = 'string'
+>module.exports.justProperty = 'string' : "string"
+>module.exports.justProperty : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>justProperty : any
+>'string' : "string"
+
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.errors.txt b/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.errors.txt
new file mode 100644
index 0000000000000..247c29e0ad3af
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.errors.txt
@@ -0,0 +1,36 @@
+tests/cases/conformance/salsa/a.js(4,17): error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+  Property 'toFixed' does not exist on type 'string'.
+tests/cases/conformance/salsa/a.js(5,16): error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+  Property 'toFixed' does not exist on type 'string'.
+
+
+==== tests/cases/conformance/salsa/a.js (2 errors) ====
+    /// <reference path='./requires.d.ts' />
+    var mod1 = require('./mod1')
+    mod1.justExport.toFixed()
+    mod1.bothBefore.toFixed() // error
+                    ~~~~~~~
+!!! error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+!!! error TS2339:   Property 'toFixed' does not exist on type 'string'.
+    mod1.bothAfter.toFixed()
+                   ~~~~~~~
+!!! error TS2339: Property 'toFixed' does not exist on type 'string | number'.
+!!! error TS2339:   Property 'toFixed' does not exist on type 'string'.
+    mod1.justProperty.length
+    
+==== tests/cases/conformance/salsa/requires.d.ts (0 errors) ====
+    declare var module: { exports: any };
+    declare function require(name: string): any;
+==== tests/cases/conformance/salsa/mod1.js (0 errors) ====
+    /// <reference path='./requires.d.ts' />
+    module.exports.bothBefore = 'string'
+    A.justExport = 4
+    A.bothBefore = 2
+    A.bothAfter = 3
+    module.exports = A
+    function A() {
+        this.p = 1
+    }
+    module.exports.bothAfter = 'string'
+    module.exports.justProperty = 'string'
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.symbols b/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.symbols
new file mode 100644
index 0000000000000..b62a68c83f3c4
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.symbols
@@ -0,0 +1,87 @@
+=== tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>'./mod1' : Symbol("tests/cases/conformance/salsa/mod1", Decl(mod1.js, 0, 0))
+
+mod1.justExport.toFixed()
+>mod1.justExport.toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
+>mod1.justExport : Symbol(A.justExport, Decl(mod1.js, 1, 36))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>justExport : Symbol(A.justExport, Decl(mod1.js, 1, 36))
+>toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
+
+mod1.bothBefore.toFixed() // error
+>mod1.bothBefore : Symbol(bothBefore)
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>bothBefore : Symbol(bothBefore)
+
+mod1.bothAfter.toFixed()
+>mod1.bothAfter : Symbol(bothAfter)
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>bothAfter : Symbol(bothAfter)
+
+mod1.justProperty.length
+>mod1.justProperty.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>mod1.justProperty : Symbol(justProperty, Decl(mod1.js, 9, 35))
+>mod1 : Symbol(mod1, Decl(a.js, 1, 3))
+>justProperty : Symbol(justProperty, Decl(mod1.js, 9, 35))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+
+declare function require(name: string): any;
+>require : Symbol(require, Decl(requires.d.ts, 0, 37))
+>name : Symbol(name, Decl(requires.d.ts, 1, 25))
+
+=== tests/cases/conformance/salsa/mod1.js ===
+/// <reference path='./requires.d.ts' />
+module.exports.bothBefore = 'string'
+>module.exports : Symbol(bothBefore, Decl(mod1.js, 0, 0))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>bothBefore : Symbol(bothBefore, Decl(mod1.js, 0, 0))
+
+A.justExport = 4
+>A.justExport : Symbol(A.justExport, Decl(mod1.js, 1, 36))
+>A : Symbol(A, Decl(mod1.js, 5, 18))
+>justExport : Symbol(A.justExport, Decl(mod1.js, 1, 36))
+
+A.bothBefore = 2
+>A.bothBefore : Symbol(A.bothBefore, Decl(mod1.js, 2, 16))
+>A : Symbol(A, Decl(mod1.js, 5, 18))
+>bothBefore : Symbol(A.bothBefore, Decl(mod1.js, 2, 16))
+
+A.bothAfter = 3
+>A.bothAfter : Symbol(A.bothAfter, Decl(mod1.js, 3, 16))
+>A : Symbol(A, Decl(mod1.js, 5, 18))
+>bothAfter : Symbol(A.bothAfter, Decl(mod1.js, 3, 16))
+
+module.exports = A
+>module.exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>module : Symbol(export=, Decl(mod1.js, 4, 15))
+>exports : Symbol(export=, Decl(mod1.js, 4, 15))
+>A : Symbol(A, Decl(mod1.js, 5, 18))
+
+function A() {
+>A : Symbol(A, Decl(mod1.js, 5, 18))
+
+    this.p = 1
+>p : Symbol(A.p, Decl(mod1.js, 6, 14))
+}
+module.exports.bothAfter = 'string'
+>module.exports : Symbol(bothAfter, Decl(mod1.js, 8, 1))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>bothAfter : Symbol(bothAfter, Decl(mod1.js, 8, 1))
+
+module.exports.justProperty = 'string'
+>module.exports : Symbol(justProperty, Decl(mod1.js, 9, 35))
+>module : Symbol(module, Decl(requires.d.ts, 0, 11))
+>exports : Symbol(exports, Decl(requires.d.ts, 0, 21))
+>justProperty : Symbol(justProperty, Decl(mod1.js, 9, 35))
+
diff --git a/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.types b/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.types
new file mode 100644
index 0000000000000..f339118bf05ac
--- /dev/null
+++ b/tests/baselines/reference/moduleExportWithExportPropertyAssignment4.types
@@ -0,0 +1,115 @@
+=== tests/cases/conformance/salsa/a.js ===
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+>mod1 : typeof A
+>require('./mod1') : typeof A
+>require : (name: string) => any
+>'./mod1' : "./mod1"
+
+mod1.justExport.toFixed()
+>mod1.justExport.toFixed() : string
+>mod1.justExport.toFixed : (fractionDigits?: number) => string
+>mod1.justExport : number
+>mod1 : typeof A
+>justExport : number
+>toFixed : (fractionDigits?: number) => string
+
+mod1.bothBefore.toFixed() // error
+>mod1.bothBefore.toFixed() : any
+>mod1.bothBefore.toFixed : any
+>mod1.bothBefore : string | number
+>mod1 : typeof A
+>bothBefore : string | number
+>toFixed : any
+
+mod1.bothAfter.toFixed()
+>mod1.bothAfter.toFixed() : any
+>mod1.bothAfter.toFixed : any
+>mod1.bothAfter : string | number
+>mod1 : typeof A
+>bothAfter : string | number
+>toFixed : any
+
+mod1.justProperty.length
+>mod1.justProperty.length : number
+>mod1.justProperty : string
+>mod1 : typeof A
+>justProperty : string
+>length : number
+
+=== tests/cases/conformance/salsa/requires.d.ts ===
+declare var module: { exports: any };
+>module : { exports: any; }
+>exports : any
+
+declare function require(name: string): any;
+>require : (name: string) => any
+>name : string
+
+=== tests/cases/conformance/salsa/mod1.js ===
+/// <reference path='./requires.d.ts' />
+module.exports.bothBefore = 'string'
+>module.exports.bothBefore = 'string' : "string"
+>module.exports.bothBefore : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>bothBefore : any
+>'string' : "string"
+
+A.justExport = 4
+>A.justExport = 4 : 4
+>A.justExport : number
+>A : typeof A
+>justExport : number
+>4 : 4
+
+A.bothBefore = 2
+>A.bothBefore = 2 : 2
+>A.bothBefore : number
+>A : typeof A
+>bothBefore : number
+>2 : 2
+
+A.bothAfter = 3
+>A.bothAfter = 3 : 3
+>A.bothAfter : number
+>A : typeof A
+>bothAfter : number
+>3 : 3
+
+module.exports = A
+>module.exports = A : typeof A
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>A : typeof A
+
+function A() {
+>A : typeof A
+
+    this.p = 1
+>this.p = 1 : 1
+>this.p : any
+>this : any
+>p : any
+>1 : 1
+}
+module.exports.bothAfter = 'string'
+>module.exports.bothAfter = 'string' : "string"
+>module.exports.bothAfter : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>bothAfter : any
+>'string' : "string"
+
+module.exports.justProperty = 'string'
+>module.exports.justProperty = 'string' : "string"
+>module.exports.justProperty : any
+>module.exports : any
+>module : { exports: any; }
+>exports : any
+>justProperty : any
+>'string' : "string"
+
diff --git a/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts
index 9486f238e74e4..926a4cadf08f7 100644
--- a/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts
+++ b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment.ts
@@ -1,12 +1,17 @@
 // @noEmit: true
 // @allowJs: true
 // @checkJs: true
+// @Filename: requires.d.ts
+declare var module: { exports: any };
+declare function require(name: string): any;
 // @Filename: mod1.js
-// TODO: Test that this is not legal (or at least doesn't work) if module.exports is a primitive
+/// <reference path='./requires.d.ts' />
 module.exports = function () { }
-module.exports.f = function () { }
+/** @param {number} a */
+module.exports.f = function (a) { }
 
 // @Filename: a.js
+/// <reference path='./requires.d.ts' />
 var mod1 = require('./mod1')
 mod1()
-mod1.f()
+mod1.f() // error, not enough arguments
diff --git a/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment2.ts b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment2.ts
new file mode 100644
index 0000000000000..ae3d770b0a412
--- /dev/null
+++ b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment2.ts
@@ -0,0 +1,16 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @Filename: requires.d.ts
+declare var module: { exports: any };
+declare function require(name: string): any;
+// @Filename: mod1.js
+/// <reference path='./requires.d.ts' />
+module.exports = 1
+module.exports.f = function () { }
+
+// @Filename: a.js
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+mod1.toFixed(12)
+mod1.f() // error, 'f' is not a property on 'number'
diff --git a/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment3.ts b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment3.ts
new file mode 100644
index 0000000000000..673858bb13e4f
--- /dev/null
+++ b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment3.ts
@@ -0,0 +1,24 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @Filename: requires.d.ts
+declare var module: { exports: any };
+declare function require(name: string): any;
+// @Filename: mod1.js
+/// <reference path='./requires.d.ts' />
+module.exports.bothBefore = 'string'
+module.exports = {
+    justExport: 1,
+    bothBefore: 2,
+    bothAfter: 3,
+}
+module.exports.bothAfter = 'string'
+module.exports.justProperty = 'string'
+
+// @Filename: a.js
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+mod1.justExport.toFixed()
+mod1.bothBefore.toFixed() // error, 'toFixed' not on 'string | number'
+mod1.bothAfter.toFixed() // error, 'toFixed' not on 'string | number'
+mod1.justProperty.length
diff --git a/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment4.ts b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment4.ts
new file mode 100644
index 0000000000000..90b54095cbf11
--- /dev/null
+++ b/tests/cases/conformance/salsa/moduleExportWithExportPropertyAssignment4.ts
@@ -0,0 +1,26 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @Filename: requires.d.ts
+declare var module: { exports: any };
+declare function require(name: string): any;
+// @Filename: mod1.js
+/// <reference path='./requires.d.ts' />
+module.exports.bothBefore = 'string'
+A.justExport = 4
+A.bothBefore = 2
+A.bothAfter = 3
+module.exports = A
+function A() {
+    this.p = 1
+}
+module.exports.bothAfter = 'string'
+module.exports.justProperty = 'string'
+
+// @Filename: a.js
+/// <reference path='./requires.d.ts' />
+var mod1 = require('./mod1')
+mod1.justExport.toFixed()
+mod1.bothBefore.toFixed() // error
+mod1.bothAfter.toFixed()
+mod1.justProperty.length

From c6a47d97fcc3bc0e6be6b0f17426e37d467524a4 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Fri, 6 Apr 2018 12:34:17 -0700
Subject: [PATCH 5/5] Check commonjs export= from resolveExternalModuleSymbol

---
 src/compiler/checker.ts | 45 +++++++++++++++++------------------------
 1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index a33421c946dd5..f3d178e9478fa 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2096,15 +2096,9 @@ namespace ts {
                         const moduleName = (namespace.valueDeclaration.initializer as CallExpression).arguments[0] as StringLiteral;
                         const moduleSym = resolveExternalModuleName(moduleName, moduleName);
                         if (moduleSym) {
-                            if (moduleSym.exports.has(InternalSymbolName.ExportEquals as __String) && moduleSym.exports.size > 1) {
-                                Debug.assert(!!(moduleSym.valueDeclaration as SourceFile).commonJsModuleIndicator);
-                                namespace = mergeCommonJsExportEquals(moduleSym);
-                            }
-                            else {
-                                const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
-                                if (resolvedModuleSymbol) {
-                                    namespace = resolvedModuleSymbol;
-                                }
+                            const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
+                            if (resolvedModuleSymbol) {
+                                namespace = resolvedModuleSymbol;
                             }
                         }
                     }
@@ -2222,7 +2216,22 @@ namespace ts {
         // An external module with an 'export =' declaration resolves to the target of the 'export =' declaration,
         // and an external module with no 'export =' declaration resolves to the module itself.
         function resolveExternalModuleSymbol(moduleSymbol: Symbol, dontResolveAlias?: boolean): Symbol {
-            return moduleSymbol && getMergedSymbol(resolveSymbol(moduleSymbol.exports.get(InternalSymbolName.ExportEquals), dontResolveAlias)) || moduleSymbol;
+            return moduleSymbol && getMergedSymbol(resolveSymbol(getCommonJsExportEquals(moduleSymbol), dontResolveAlias)) || moduleSymbol;
+        }
+
+        function getCommonJsExportEquals(moduleSymbol: Symbol): Symbol {
+            const exported = moduleSymbol.exports.get(InternalSymbolName.ExportEquals);
+            if (!exported || !exported.exports || moduleSymbol.exports.size === 1) {
+                return exported;
+            }
+            const merged = cloneSymbol(exported);
+            moduleSymbol.exports.forEach((s, name) => {
+                if (name === InternalSymbolName.ExportEquals) return;
+                if (!merged.exports.has(name)) {
+                    merged.exports.set(name, s);
+                }
+            });
+            return merged;
         }
 
         // An external module with an 'export =' declaration may be referenced as an ES6 module provided the 'export ='
@@ -7025,10 +7034,6 @@ namespace ts {
         function resolveExternalModuleTypeByLiteral(name: StringLiteral) {
             const moduleSym = resolveExternalModuleName(name, name);
             if (moduleSym) {
-                if (moduleSym.exports.has(InternalSymbolName.ExportEquals as __String) && moduleSym.exports.size > 1) {
-                    Debug.assert(!!(moduleSym.valueDeclaration as SourceFile).commonJsModuleIndicator);
-                    return getTypeOfSymbol(mergeCommonJsExportEquals(moduleSym));
-                }
                 const resolvedModuleSymbol = resolveExternalModuleSymbol(moduleSym);
                 if (resolvedModuleSymbol) {
                     return getTypeOfSymbol(resolvedModuleSymbol);
@@ -7038,18 +7043,6 @@ namespace ts {
             return anyType;
         }
 
-        function mergeCommonJsExportEquals(moduleSym: Symbol): Symbol {
-            const combined = cloneSymbol(moduleSym.exports.get(InternalSymbolName.ExportEquals));
-            moduleSym.exports.forEach((s, name) => {
-                if (name === InternalSymbolName.ExportEquals) return;
-                if (!combined.exports.has(name)) {
-                    combined.exports.set(name, s);
-                }
-            });
-            return combined;
-
-        }
-
         function getThisTypeOfSignature(signature: Signature): Type | undefined {
             if (signature.thisParameter) {
                 return getTypeOfSymbol(signature.thisParameter);