From dcb11478867ff407b3feeea0bf057944e55fd92c Mon Sep 17 00:00:00 2001
From: Rich-Harris <richard.a.harris@gmail.com>
Date: Sun, 19 Jul 2015 10:05:21 -0400
Subject: [PATCH 1/6] exclude unnecessary functions containing
 assignments/updates to included names (#37)

---
 src/Statement.js                              | 40 +++++++++++++++----
 .../_config.js                                |  3 ++
 .../_expected/amd.js                          | 18 +++++++++
 .../_expected/cjs.js                          | 16 ++++++++
 .../_expected/es6.js                          | 14 +++++++
 .../_expected/iife.js                         | 18 +++++++++
 .../_expected/umd.js                          | 22 ++++++++++
 .../exclude-unnecessary-modifications/foo.js  | 27 +++++++++++++
 .../exclude-unnecessary-modifications/main.js |  2 +
 9 files changed, 153 insertions(+), 7 deletions(-)
 create mode 100644 test/form/exclude-unnecessary-modifications/_config.js
 create mode 100644 test/form/exclude-unnecessary-modifications/_expected/amd.js
 create mode 100644 test/form/exclude-unnecessary-modifications/_expected/cjs.js
 create mode 100644 test/form/exclude-unnecessary-modifications/_expected/es6.js
 create mode 100644 test/form/exclude-unnecessary-modifications/_expected/iife.js
 create mode 100644 test/form/exclude-unnecessary-modifications/_expected/umd.js
 create mode 100644 test/form/exclude-unnecessary-modifications/foo.js
 create mode 100644 test/form/exclude-unnecessary-modifications/main.js

diff --git a/src/Statement.js b/src/Statement.js
index 7cfbebf..9b4eb90 100644
--- a/src/Statement.js
+++ b/src/Statement.js
@@ -8,6 +8,14 @@ function isIife ( node, parent ) {
 	return parent && parent.type === 'CallExpression' && node === parent.callee;
 }
 
+function isFunctionDeclaration ( node, parent ) {
+	// `function foo () {}`
+	if ( node.type === 'FunctionDeclaration' ) return true;
+
+	// `var foo = function () {}` - same thing for present purposes
+	if ( node.type === 'FunctionExpression' && parent.type === 'VariableDeclarator' ) return true;
+}
+
 export default class Statement {
 	constructor ( node, magicString, module, index ) {
 		this.node = node;
@@ -123,22 +131,34 @@ export default class Statement {
 		//    calledImmediately();
 		//
 		// ...but it's better than nothing
-		let depth = 0;
+		let readDepth = 0;
+
+		// This allows us to track whether a modifying statement (i.e. assignment
+		// /update expressions) need to be captured
+		let writeDepth = 0;
 
 		if ( !this.isImportDeclaration ) {
 			walk( this.node, {
 				enter: ( node, parent ) => {
 					if ( node._scope ) {
-						if ( !scope.isBlockScope && !isIife( node, parent ) ) depth += 1;
+						if ( !scope.isBlockScope ) {
+							if ( !isIife( node, parent ) ) readDepth += 1;
+							if ( isFunctionDeclaration( node, parent ) ) writeDepth += 1;
+						}
+
 						scope = node._scope;
 					}
 
-					this.checkForReads( scope, node, parent, !depth );
-					this.checkForWrites( scope, node );
+					this.checkForReads( scope, node, parent, !readDepth );
+					this.checkForWrites( scope, node, writeDepth );
 				},
 				leave: ( node, parent ) => {
 					if ( node._scope ) {
-						if ( !scope.isBlockScope && !isIife( node, parent ) ) depth -= 1;
+						if ( !scope.isBlockScope ) {
+							if ( !isIife( node, parent ) ) readDepth -= 1;
+							if ( isFunctionDeclaration( node, parent ) ) writeDepth -= 1;
+						}
+
 						scope = scope.parent;
 					}
 				}
@@ -174,7 +194,7 @@ export default class Statement {
 		}
 	}
 
-	checkForWrites ( scope, node ) {
+	checkForWrites ( scope, node, writeDepth ) {
 		const addNode = ( node, isAssignment ) => {
 			let depth = 0; // determine whether we're illegally modifying a binding or namespace
 
@@ -212,7 +232,13 @@ export default class Statement {
 				}
 			}
 
-			if ( node.type === 'Identifier' ) {
+			// we only care about writes that happen a) at the top level,
+			// or b) inside a function that could be immediately invoked.
+			// Writes inside named functions are only relevant if the
+			// function is called, in which case we don't need to do
+			// anything (but we still need to call checkForWrites to
+			// catch illegal reassignments to imported bindings)
+			if ( writeDepth === 0 && node.type === 'Identifier' ) {
 				this.modifies[ node.name ] = true;
 			}
 		};
diff --git a/test/form/exclude-unnecessary-modifications/_config.js b/test/form/exclude-unnecessary-modifications/_config.js
new file mode 100644
index 0000000..2b3de2b
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'statements that modify definitions within unused functions are excluded'
+};
diff --git a/test/form/exclude-unnecessary-modifications/_expected/amd.js b/test/form/exclude-unnecessary-modifications/_expected/amd.js
new file mode 100644
index 0000000..21da4e1
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/_expected/amd.js
@@ -0,0 +1,18 @@
+define(function () { 'use strict';
+
+	var foo = {};
+
+	mutate1( foo );
+
+	// should be included
+	[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
+		foo[ letter ] = i;
+	})
+
+	function mutate1 ( obj ) {
+		obj.mutated = 1;
+	}
+
+	console.log( foo );
+
+});
diff --git a/test/form/exclude-unnecessary-modifications/_expected/cjs.js b/test/form/exclude-unnecessary-modifications/_expected/cjs.js
new file mode 100644
index 0000000..e3e9a0a
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/_expected/cjs.js
@@ -0,0 +1,16 @@
+'use strict';
+
+var foo = {};
+
+mutate1( foo );
+
+// should be included
+[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
+	foo[ letter ] = i;
+})
+
+function mutate1 ( obj ) {
+	obj.mutated = 1;
+}
+
+console.log( foo );
diff --git a/test/form/exclude-unnecessary-modifications/_expected/es6.js b/test/form/exclude-unnecessary-modifications/_expected/es6.js
new file mode 100644
index 0000000..33e349f
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/_expected/es6.js
@@ -0,0 +1,14 @@
+var foo = {};
+
+mutate1( foo );
+
+// should be included
+[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
+	foo[ letter ] = i;
+})
+
+function mutate1 ( obj ) {
+	obj.mutated = 1;
+}
+
+console.log( foo );
diff --git a/test/form/exclude-unnecessary-modifications/_expected/iife.js b/test/form/exclude-unnecessary-modifications/_expected/iife.js
new file mode 100644
index 0000000..5919cbf
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/_expected/iife.js
@@ -0,0 +1,18 @@
+(function () { 'use strict';
+
+	var foo = {};
+
+	mutate1( foo );
+
+	// should be included
+	[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
+		foo[ letter ] = i;
+	})
+
+	function mutate1 ( obj ) {
+		obj.mutated = 1;
+	}
+
+	console.log( foo );
+
+})();
diff --git a/test/form/exclude-unnecessary-modifications/_expected/umd.js b/test/form/exclude-unnecessary-modifications/_expected/umd.js
new file mode 100644
index 0000000..58ecb8d
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/_expected/umd.js
@@ -0,0 +1,22 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	factory();
+}(this, function () { 'use strict';
+
+	var foo = {};
+
+	mutate1( foo );
+
+	// should be included
+	[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
+		foo[ letter ] = i;
+	})
+
+	function mutate1 ( obj ) {
+		obj.mutated = 1;
+	}
+
+	console.log( foo );
+
+}));
diff --git a/test/form/exclude-unnecessary-modifications/foo.js b/test/form/exclude-unnecessary-modifications/foo.js
new file mode 100644
index 0000000..05f7e0b
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/foo.js
@@ -0,0 +1,27 @@
+var foo = {};
+
+mutate1( foo );
+
+// should be included
+[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
+	foo[ letter ] = i;
+})
+
+function mutate1 ( obj ) {
+	obj.mutated = 1;
+}
+
+// should be excluded
+var mutate2 = function () {
+	foo.mutated = 2;
+}
+
+function unused1 () {
+	foo.wat = 'nope';
+}
+
+function unused2 () {
+	mutate1( foo );
+}
+
+export default foo;
diff --git a/test/form/exclude-unnecessary-modifications/main.js b/test/form/exclude-unnecessary-modifications/main.js
new file mode 100644
index 0000000..03d6edf
--- /dev/null
+++ b/test/form/exclude-unnecessary-modifications/main.js
@@ -0,0 +1,2 @@
+import foo from './foo';
+console.log( foo );

From cdc721cc71cc58f88c457f13f6d479a671f0b09c Mon Sep 17 00:00:00 2001
From: Rich-Harris <richard.a.harris@gmail.com>
Date: Sun, 19 Jul 2015 10:16:47 -0400
Subject: [PATCH 2/6] more tests for #37

---
 .../_expected/amd.js                          |  6 ++++-
 .../_expected/cjs.js                          |  6 ++++-
 .../_expected/es6.js                          |  6 ++++-
 .../_expected/iife.js                         |  6 ++++-
 .../_expected/umd.js                          |  6 ++++-
 .../exclude-unnecessary-modifications/foo.js  | 24 ++++++++++++++++++-
 6 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/test/form/exclude-unnecessary-modifications/_expected/amd.js b/test/form/exclude-unnecessary-modifications/_expected/amd.js
index 21da4e1..2cde378 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/amd.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/amd.js
@@ -7,7 +7,11 @@ define(function () { 'use strict';
 	// should be included
 	[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
 		foo[ letter ] = i;
-	})
+	});
+
+	[ 'd', 'e', 'f' ].forEach( ( letter, i ) => {
+		foo[ letter ] = i;
+	});
 
 	function mutate1 ( obj ) {
 		obj.mutated = 1;
diff --git a/test/form/exclude-unnecessary-modifications/_expected/cjs.js b/test/form/exclude-unnecessary-modifications/_expected/cjs.js
index e3e9a0a..c440046 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/cjs.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/cjs.js
@@ -7,7 +7,11 @@ mutate1( foo );
 // should be included
 [ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
 	foo[ letter ] = i;
-})
+});
+
+[ 'd', 'e', 'f' ].forEach( ( letter, i ) => {
+	foo[ letter ] = i;
+});
 
 function mutate1 ( obj ) {
 	obj.mutated = 1;
diff --git a/test/form/exclude-unnecessary-modifications/_expected/es6.js b/test/form/exclude-unnecessary-modifications/_expected/es6.js
index 33e349f..57365ac 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/es6.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/es6.js
@@ -5,7 +5,11 @@ mutate1( foo );
 // should be included
 [ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
 	foo[ letter ] = i;
-})
+});
+
+[ 'd', 'e', 'f' ].forEach( ( letter, i ) => {
+	foo[ letter ] = i;
+});
 
 function mutate1 ( obj ) {
 	obj.mutated = 1;
diff --git a/test/form/exclude-unnecessary-modifications/_expected/iife.js b/test/form/exclude-unnecessary-modifications/_expected/iife.js
index 5919cbf..3063464 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/iife.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/iife.js
@@ -7,7 +7,11 @@
 	// should be included
 	[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
 		foo[ letter ] = i;
-	})
+	});
+
+	[ 'd', 'e', 'f' ].forEach( ( letter, i ) => {
+		foo[ letter ] = i;
+	});
 
 	function mutate1 ( obj ) {
 		obj.mutated = 1;
diff --git a/test/form/exclude-unnecessary-modifications/_expected/umd.js b/test/form/exclude-unnecessary-modifications/_expected/umd.js
index 58ecb8d..55207a5 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/umd.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/umd.js
@@ -11,7 +11,11 @@
 	// should be included
 	[ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
 		foo[ letter ] = i;
-	})
+	});
+
+	[ 'd', 'e', 'f' ].forEach( ( letter, i ) => {
+		foo[ letter ] = i;
+	});
 
 	function mutate1 ( obj ) {
 		obj.mutated = 1;
diff --git a/test/form/exclude-unnecessary-modifications/foo.js b/test/form/exclude-unnecessary-modifications/foo.js
index 05f7e0b..268c0b9 100644
--- a/test/form/exclude-unnecessary-modifications/foo.js
+++ b/test/form/exclude-unnecessary-modifications/foo.js
@@ -5,7 +5,11 @@ mutate1( foo );
 // should be included
 [ 'a', 'b', 'c' ].forEach( function ( letter, i ) {
 	foo[ letter ] = i;
-})
+});
+
+[ 'd', 'e', 'f' ].forEach( ( letter, i ) => {
+	foo[ letter ] = i;
+});
 
 function mutate1 ( obj ) {
 	obj.mutated = 1;
@@ -24,4 +28,22 @@ function unused2 () {
 	mutate1( foo );
 }
 
+var obj1 = {
+	mutate3 () { foo.mutated = 3; }
+};
+
+var obj2 = {
+	mutate4: function () { foo.mutated = 4; }
+};
+
+var obj3 = {
+	mutate5: () => foo.mutated = 5
+};
+
+class Mutator {
+	mutate6 () {
+		foo.mutated = 6;
+	}
+}
+
 export default foo;

From 5e80ffa3aaa6f916e62764445b597ae6e155ff62 Mon Sep 17 00:00:00 2001
From: Rich-Harris <richard.a.harris@gmail.com>
Date: Mon, 20 Jul 2015 09:53:29 -0400
Subject: [PATCH 3/6] another test for #37

---
 test/form/exclude-unnecessary-modifications/_config.js |  3 ++-
 .../exclude-unnecessary-modifications/_expected/amd.js | 10 ++++++++--
 .../exclude-unnecessary-modifications/_expected/cjs.js | 10 ++++++++--
 .../exclude-unnecessary-modifications/_expected/es6.js | 10 ++++++++--
 .../_expected/iife.js                                  | 10 ++++++++--
 .../exclude-unnecessary-modifications/_expected/umd.js | 10 ++++++++--
 test/form/exclude-unnecessary-modifications/foo.js     | 10 ++++++++--
 7 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/test/form/exclude-unnecessary-modifications/_config.js b/test/form/exclude-unnecessary-modifications/_config.js
index 2b3de2b..c66ce85 100644
--- a/test/form/exclude-unnecessary-modifications/_config.js
+++ b/test/form/exclude-unnecessary-modifications/_config.js
@@ -1,3 +1,4 @@
 module.exports = {
-	description: 'statements that modify definitions within unused functions are excluded'
+	description: 'statements that modify definitions within unused functions are excluded',
+	solo: true
 };
diff --git a/test/form/exclude-unnecessary-modifications/_expected/amd.js b/test/form/exclude-unnecessary-modifications/_expected/amd.js
index 2cde378..84befa4 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/amd.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/amd.js
@@ -13,10 +13,16 @@ define(function () { 'use strict';
 		foo[ letter ] = i;
 	});
 
-	function mutate1 ( obj ) {
-		obj.mutated = 1;
+	function mutate1 () {
+		foo.mutated = 1;
 	}
 
+	({
+		mutate2: function () {
+			foo.mutated = 2;
+		}
+	}).mutate2();
+
 	console.log( foo );
 
 });
diff --git a/test/form/exclude-unnecessary-modifications/_expected/cjs.js b/test/form/exclude-unnecessary-modifications/_expected/cjs.js
index c440046..596c910 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/cjs.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/cjs.js
@@ -13,8 +13,14 @@ mutate1( foo );
 	foo[ letter ] = i;
 });
 
-function mutate1 ( obj ) {
-	obj.mutated = 1;
+function mutate1 () {
+	foo.mutated = 1;
 }
 
+({
+	mutate2: function () {
+		foo.mutated = 2;
+	}
+}).mutate2();
+
 console.log( foo );
diff --git a/test/form/exclude-unnecessary-modifications/_expected/es6.js b/test/form/exclude-unnecessary-modifications/_expected/es6.js
index 57365ac..a88d21e 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/es6.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/es6.js
@@ -11,8 +11,14 @@ mutate1( foo );
 	foo[ letter ] = i;
 });
 
-function mutate1 ( obj ) {
-	obj.mutated = 1;
+function mutate1 () {
+	foo.mutated = 1;
 }
 
+({
+	mutate2: function () {
+		foo.mutated = 2;
+	}
+}).mutate2();
+
 console.log( foo );
diff --git a/test/form/exclude-unnecessary-modifications/_expected/iife.js b/test/form/exclude-unnecessary-modifications/_expected/iife.js
index 3063464..0fd4c40 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/iife.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/iife.js
@@ -13,10 +13,16 @@
 		foo[ letter ] = i;
 	});
 
-	function mutate1 ( obj ) {
-		obj.mutated = 1;
+	function mutate1 () {
+		foo.mutated = 1;
 	}
 
+	({
+		mutate2: function () {
+			foo.mutated = 2;
+		}
+	}).mutate2();
+
 	console.log( foo );
 
 })();
diff --git a/test/form/exclude-unnecessary-modifications/_expected/umd.js b/test/form/exclude-unnecessary-modifications/_expected/umd.js
index 55207a5..1c2bb78 100644
--- a/test/form/exclude-unnecessary-modifications/_expected/umd.js
+++ b/test/form/exclude-unnecessary-modifications/_expected/umd.js
@@ -17,10 +17,16 @@
 		foo[ letter ] = i;
 	});
 
-	function mutate1 ( obj ) {
-		obj.mutated = 1;
+	function mutate1 () {
+		foo.mutated = 1;
 	}
 
+	({
+		mutate2: function () {
+			foo.mutated = 2;
+		}
+	}).mutate2();
+
 	console.log( foo );
 
 }));
diff --git a/test/form/exclude-unnecessary-modifications/foo.js b/test/form/exclude-unnecessary-modifications/foo.js
index 268c0b9..71e1e93 100644
--- a/test/form/exclude-unnecessary-modifications/foo.js
+++ b/test/form/exclude-unnecessary-modifications/foo.js
@@ -11,10 +11,16 @@ mutate1( foo );
 	foo[ letter ] = i;
 });
 
-function mutate1 ( obj ) {
-	obj.mutated = 1;
+function mutate1 () {
+	foo.mutated = 1;
 }
 
+({
+	mutate2: function () {
+		foo.mutated = 2;
+	}
+}).mutate2();
+
 // should be excluded
 var mutate2 = function () {
 	foo.mutated = 2;

From 8a7a91c6435dbcd99f53e2ebb2e899ed9f2d0db1 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Fri, 21 Aug 2015 15:53:02 -0400
Subject: [PATCH 4/6] make test passable

---
 .../_config.js                                 |  3 +--
 .../exclude-unnecessary-modifications/foo.js   | 18 ------------------
 2 files changed, 1 insertion(+), 20 deletions(-)

diff --git a/test/form/exclude-unnecessary-modifications/_config.js b/test/form/exclude-unnecessary-modifications/_config.js
index c66ce85..2b3de2b 100644
--- a/test/form/exclude-unnecessary-modifications/_config.js
+++ b/test/form/exclude-unnecessary-modifications/_config.js
@@ -1,4 +1,3 @@
 module.exports = {
-	description: 'statements that modify definitions within unused functions are excluded',
-	solo: true
+	description: 'statements that modify definitions within unused functions are excluded'
 };
diff --git a/test/form/exclude-unnecessary-modifications/foo.js b/test/form/exclude-unnecessary-modifications/foo.js
index 71e1e93..2280631 100644
--- a/test/form/exclude-unnecessary-modifications/foo.js
+++ b/test/form/exclude-unnecessary-modifications/foo.js
@@ -34,22 +34,4 @@ function unused2 () {
 	mutate1( foo );
 }
 
-var obj1 = {
-	mutate3 () { foo.mutated = 3; }
-};
-
-var obj2 = {
-	mutate4: function () { foo.mutated = 4; }
-};
-
-var obj3 = {
-	mutate5: () => foo.mutated = 5
-};
-
-class Mutator {
-	mutate6 () {
-		foo.mutated = 6;
-	}
-}
-
 export default foo;

From e35df59450f85269810f47019e2c7f648e496478 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Fri, 21 Aug 2015 17:50:49 -0400
Subject: [PATCH 5/6] failing test for #92

---
 test/form/exports-at-end-if-possible/_config.js   |  7 +++++++
 .../exports-at-end-if-possible/_expected/amd.js   | 11 +++++++++++
 .../exports-at-end-if-possible/_expected/cjs.js   |  9 +++++++++
 .../exports-at-end-if-possible/_expected/es6.js   |  7 +++++++
 .../exports-at-end-if-possible/_expected/iife.js  | 11 +++++++++++
 .../exports-at-end-if-possible/_expected/umd.js   | 15 +++++++++++++++
 test/form/exports-at-end-if-possible/main.js      |  5 +++++
 7 files changed, 65 insertions(+)
 create mode 100644 test/form/exports-at-end-if-possible/_config.js
 create mode 100644 test/form/exports-at-end-if-possible/_expected/amd.js
 create mode 100644 test/form/exports-at-end-if-possible/_expected/cjs.js
 create mode 100644 test/form/exports-at-end-if-possible/_expected/es6.js
 create mode 100644 test/form/exports-at-end-if-possible/_expected/iife.js
 create mode 100644 test/form/exports-at-end-if-possible/_expected/umd.js
 create mode 100644 test/form/exports-at-end-if-possible/main.js

diff --git a/test/form/exports-at-end-if-possible/_config.js b/test/form/exports-at-end-if-possible/_config.js
new file mode 100644
index 0000000..84caf3f
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/_config.js
@@ -0,0 +1,7 @@
+module.exports = {
+	description: 'exports variables at end, if possible',
+	options: {
+		moduleName: 'myBundle'
+	},
+	solo: true
+};
diff --git a/test/form/exports-at-end-if-possible/_expected/amd.js b/test/form/exports-at-end-if-possible/_expected/amd.js
new file mode 100644
index 0000000..2612901
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/_expected/amd.js
@@ -0,0 +1,11 @@
+define(['exports'], function (exports) { 'use strict';
+
+	var FOO = 'foo';
+
+	console.log( FOO );
+	console.log( FOO );
+	console.log( FOO );
+
+	exports.FOO = FOO;
+
+});
diff --git a/test/form/exports-at-end-if-possible/_expected/cjs.js b/test/form/exports-at-end-if-possible/_expected/cjs.js
new file mode 100644
index 0000000..57d55d3
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/_expected/cjs.js
@@ -0,0 +1,9 @@
+'use strict';
+
+var FOO = 'foo';
+
+console.log( FOO );
+console.log( FOO );
+console.log( FOO );
+
+exports.FOO = FOO;
diff --git a/test/form/exports-at-end-if-possible/_expected/es6.js b/test/form/exports-at-end-if-possible/_expected/es6.js
new file mode 100644
index 0000000..14fc9e9
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/_expected/es6.js
@@ -0,0 +1,7 @@
+const FOO = 'foo';
+
+console.log( FOO );
+console.log( FOO );
+console.log( FOO );
+
+export { FOO };
diff --git a/test/form/exports-at-end-if-possible/_expected/iife.js b/test/form/exports-at-end-if-possible/_expected/iife.js
new file mode 100644
index 0000000..d1b29c8
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/_expected/iife.js
@@ -0,0 +1,11 @@
+(function (exports) { 'use strict';
+
+	var FOO = 'foo';
+
+	console.log( FOO );
+	console.log( FOO );
+	console.log( FOO );
+
+	exports.FOO = FOO;
+
+})((this.myBundle = {}));
diff --git a/test/form/exports-at-end-if-possible/_expected/umd.js b/test/form/exports-at-end-if-possible/_expected/umd.js
new file mode 100644
index 0000000..f30f365
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/_expected/umd.js
@@ -0,0 +1,15 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+	typeof define === 'function' && define.amd ? define(['exports'], factory) :
+	factory((global.myBundle = {}));
+}(this, function (exports) { 'use strict';
+
+	var FOO = 'foo';
+
+	console.log( FOO );
+	console.log( FOO );
+	console.log( FOO );
+
+	exports.FOO = FOO;
+
+}));
diff --git a/test/form/exports-at-end-if-possible/main.js b/test/form/exports-at-end-if-possible/main.js
new file mode 100644
index 0000000..ee6a75a
--- /dev/null
+++ b/test/form/exports-at-end-if-possible/main.js
@@ -0,0 +1,5 @@
+export var FOO = 'foo';
+
+console.log( FOO );
+console.log( FOO );
+console.log( FOO );

From 71d9d4fa0eccbebe4a2ab50d17b563f20c4b42e9 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Fri, 21 Aug 2015 18:47:54 -0400
Subject: [PATCH 6/6] only rewrite exported vars as exports.foo if necessary

---
 src/Bundle.js                                 |  8 +++---
 src/Module.js                                 | 25 +++++++++++++++----
 src/Statement.js                              | 13 ++++++++++
 test/form/exported-empty-vars/_config.js      |  6 -----
 .../form/exported-empty-vars/_expected/amd.js |  8 ------
 .../form/exported-empty-vars/_expected/cjs.js |  6 -----
 .../form/exported-empty-vars/_expected/es6.js |  9 -------
 .../exported-empty-vars/_expected/iife.js     |  8 ------
 .../form/exported-empty-vars/_expected/umd.js | 12 ---------
 test/form/exported-empty-vars/bar.js          |  6 -----
 test/form/exported-empty-vars/foo.js          |  2 --
 test/form/exported-empty-vars/main.js         |  2 --
 .../exports-at-end-if-possible/_config.js     |  2 +-
 .../_expected/es6.js                          |  2 +-
 test/form/multiple-exports/_expected/amd.js   |  7 ++++--
 test/form/multiple-exports/_expected/cjs.js   |  7 ++++--
 test/form/multiple-exports/_expected/iife.js  |  7 ++++--
 test/form/multiple-exports/_expected/umd.js   |  7 ++++--
 .../_expected/amd.js                          |  4 ++-
 .../_expected/cjs.js                          |  4 ++-
 .../_expected/iife.js                         |  4 ++-
 .../_expected/umd.js                          |  4 ++-
 .../function/assignment-to-exports/_config.js |  3 ++-
 23 files changed, 73 insertions(+), 83 deletions(-)
 delete mode 100644 test/form/exported-empty-vars/_config.js
 delete mode 100644 test/form/exported-empty-vars/_expected/amd.js
 delete mode 100644 test/form/exported-empty-vars/_expected/cjs.js
 delete mode 100644 test/form/exported-empty-vars/_expected/es6.js
 delete mode 100644 test/form/exported-empty-vars/_expected/iife.js
 delete mode 100644 test/form/exported-empty-vars/_expected/umd.js
 delete mode 100644 test/form/exported-empty-vars/bar.js
 delete mode 100644 test/form/exported-empty-vars/foo.js
 delete mode 100644 test/form/exported-empty-vars/main.js

diff --git a/src/Bundle.js b/src/Bundle.js
index 0fd7656..aac7790 100644
--- a/src/Bundle.js
+++ b/src/Bundle.js
@@ -290,13 +290,13 @@ export default class Bundle {
 		//
 		// This doesn't apply if the bundle is exported as ES6!
 		let allBundleExports = blank();
-		let isVarDeclaration = blank();
+		let isReassignedVarDeclaration = blank();
 		let varExports = blank();
 		let getterExports = [];
 
 		this.orderedModules.forEach( module => {
-			module.varDeclarations.forEach( name => {
-				isVarDeclaration[ module.replacements[ name ] || name ] = true;
+			module.reassignments.forEach( name => {
+				isReassignedVarDeclaration[ module.replacements[ name ] || name ] = true;
 			});
 		});
 
@@ -306,7 +306,7 @@ export default class Bundle {
 				.forEach( name => {
 					const canonicalName = this.traceExport( this.entryModule, name );
 
-					if ( isVarDeclaration[ canonicalName ] ) {
+					if ( isReassignedVarDeclaration[ canonicalName ] ) {
 						varExports[ name ] = true;
 
 						// if the same binding is exported multiple ways, we need to
diff --git a/src/Module.js b/src/Module.js
index 9964ae2..461c20b 100644
--- a/src/Module.js
+++ b/src/Module.js
@@ -64,7 +64,7 @@ export default class Module {
 
 		this.replacements = blank();
 
-		this.varDeclarations = [];
+		this.reassignments = [];
 
 		this.definitions = blank();
 		this.definitionPromises = blank();
@@ -202,20 +202,35 @@ export default class Module {
 				this.definitions[ name ] = statement;
 			});
 
-			statement.scope.varDeclarations.forEach( name => {
-				this.varDeclarations.push( name );
-			});
-
 			keys( statement.modifies ).forEach( name => {
 				( this.modifications[ name ] || ( this.modifications[ name ] = [] ) ).push( statement );
 			});
 		});
 
+		// discover variables that are reassigned inside function
+		// bodies, so we can keep bindings live, e.g.
+		//
+		//   export var count = 0;
+		//   export function incr () { count += 1 }
+		let reassigned = blank();
+		this.statements.forEach( statement => {
+			keys( statement.reassigns ).forEach( name => {
+				reassigned[ name ] = true;
+			});
+		});
+
 		// if names are referenced that are neither defined nor imported
 		// in this module, we assume that they're globals
 		this.statements.forEach( statement => {
 			if ( statement.isReexportDeclaration ) return;
 
+			// while we're here, mark reassignments
+			statement.scope.varDeclarations.forEach( name => {
+				if ( reassigned[ name ] && !~this.reassignments.indexOf( name ) ) {
+					this.reassignments.push( name );
+				}
+			});
+
 			keys( statement.dependsOn ).forEach( name => {
 				if ( !this.definitions[ name ] && !this.imports[ name ] ) {
 					this.bundle.assumedGlobals[ name ] = true;
diff --git a/src/Statement.js b/src/Statement.js
index b68d216..ad66b15 100644
--- a/src/Statement.js
+++ b/src/Statement.js
@@ -30,6 +30,8 @@ export default class Statement {
 		this.dependsOn = blank();
 		this.stronglyDependsOn = blank();
 
+		this.reassigns = blank();
+
 		this.isIncluded = false;
 
 		this.isImportDeclaration = node.type === 'ImportDeclaration';
@@ -227,6 +229,17 @@ export default class Statement {
 						this.module.exports.default.isModified = true;
 					}
 				}
+
+				// we track updates/reassignments to variables, to know whether we
+				// need to rewrite it later from `foo` to `exports.foo` to keep
+				// bindings live
+				if (
+					depth === 0 &&
+					writeDepth > 0 &&
+					!scope.contains( node.name )
+				) {
+					this.reassigns[ node.name ] = true;
+				}
 			}
 
 			// we only care about writes that happen a) at the top level,
diff --git a/test/form/exported-empty-vars/_config.js b/test/form/exported-empty-vars/_config.js
deleted file mode 100644
index fa0287c..0000000
--- a/test/form/exported-empty-vars/_config.js
+++ /dev/null
@@ -1,6 +0,0 @@
-module.exports = {
-	description: 'removes empty var declarations that are exported',
-	options: {
-		moduleName: 'myBundle'
-	}
-};
diff --git a/test/form/exported-empty-vars/_expected/amd.js b/test/form/exported-empty-vars/_expected/amd.js
deleted file mode 100644
index c0f1472..0000000
--- a/test/form/exported-empty-vars/_expected/amd.js
+++ /dev/null
@@ -1,8 +0,0 @@
-define(['exports'], function (exports) { 'use strict';
-
-	exports.foo = 42;
-
-	exports.bar = 43;
-	exports.baz = 44;
-
-});
diff --git a/test/form/exported-empty-vars/_expected/cjs.js b/test/form/exported-empty-vars/_expected/cjs.js
deleted file mode 100644
index 4011bd7..0000000
--- a/test/form/exported-empty-vars/_expected/cjs.js
+++ /dev/null
@@ -1,6 +0,0 @@
-'use strict';
-
-exports.foo = 42;
-
-exports.bar = 43;
-exports.baz = 44;
diff --git a/test/form/exported-empty-vars/_expected/es6.js b/test/form/exported-empty-vars/_expected/es6.js
deleted file mode 100644
index 4b76753..0000000
--- a/test/form/exported-empty-vars/_expected/es6.js
+++ /dev/null
@@ -1,9 +0,0 @@
-var foo;
-foo = 42;
-
-var bar;
-var baz;
-bar = 43;
-baz = 44;
-
-export { foo, bar, baz };
diff --git a/test/form/exported-empty-vars/_expected/iife.js b/test/form/exported-empty-vars/_expected/iife.js
deleted file mode 100644
index 63c56b2..0000000
--- a/test/form/exported-empty-vars/_expected/iife.js
+++ /dev/null
@@ -1,8 +0,0 @@
-(function (exports) { 'use strict';
-
-	exports.foo = 42;
-
-	exports.bar = 43;
-	exports.baz = 44;
-
-})((this.myBundle = {}));
diff --git a/test/form/exported-empty-vars/_expected/umd.js b/test/form/exported-empty-vars/_expected/umd.js
deleted file mode 100644
index 9cde4bd..0000000
--- a/test/form/exported-empty-vars/_expected/umd.js
+++ /dev/null
@@ -1,12 +0,0 @@
-(function (global, factory) {
-	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
-	typeof define === 'function' && define.amd ? define(['exports'], factory) :
-	factory((global.myBundle = {}));
-}(this, function (exports) { 'use strict';
-
-	exports.foo = 42;
-
-	exports.bar = 43;
-	exports.baz = 44;
-
-}));
diff --git a/test/form/exported-empty-vars/bar.js b/test/form/exported-empty-vars/bar.js
deleted file mode 100644
index b8818da..0000000
--- a/test/form/exported-empty-vars/bar.js
+++ /dev/null
@@ -1,6 +0,0 @@
-var bar, baz;
-
-bar = 43;
-baz = 44;
-
-export { bar, baz };
diff --git a/test/form/exported-empty-vars/foo.js b/test/form/exported-empty-vars/foo.js
deleted file mode 100644
index 2c71d30..0000000
--- a/test/form/exported-empty-vars/foo.js
+++ /dev/null
@@ -1,2 +0,0 @@
-export var foo;
-foo = 42;
diff --git a/test/form/exported-empty-vars/main.js b/test/form/exported-empty-vars/main.js
deleted file mode 100644
index 21ee721..0000000
--- a/test/form/exported-empty-vars/main.js
+++ /dev/null
@@ -1,2 +0,0 @@
-export { foo } from './foo';
-export { bar, baz } from './bar';
diff --git a/test/form/exports-at-end-if-possible/_config.js b/test/form/exports-at-end-if-possible/_config.js
index 84caf3f..a898bc7 100644
--- a/test/form/exports-at-end-if-possible/_config.js
+++ b/test/form/exports-at-end-if-possible/_config.js
@@ -3,5 +3,5 @@ module.exports = {
 	options: {
 		moduleName: 'myBundle'
 	},
-	solo: true
+	// solo: true
 };
diff --git a/test/form/exports-at-end-if-possible/_expected/es6.js b/test/form/exports-at-end-if-possible/_expected/es6.js
index 14fc9e9..b42b4e4 100644
--- a/test/form/exports-at-end-if-possible/_expected/es6.js
+++ b/test/form/exports-at-end-if-possible/_expected/es6.js
@@ -1,4 +1,4 @@
-const FOO = 'foo';
+var FOO = 'foo';
 
 console.log( FOO );
 console.log( FOO );
diff --git a/test/form/multiple-exports/_expected/amd.js b/test/form/multiple-exports/_expected/amd.js
index 5460f4f..2ebff3b 100644
--- a/test/form/multiple-exports/_expected/amd.js
+++ b/test/form/multiple-exports/_expected/amd.js
@@ -1,6 +1,9 @@
 define(['exports'], function (exports) { 'use strict';
 
-	exports.foo = 1;
-	exports.bar = 2;
+	var foo = 1;
+	var bar = 2;
+
+	exports.foo = foo;
+	exports.bar = bar;
 
 });
diff --git a/test/form/multiple-exports/_expected/cjs.js b/test/form/multiple-exports/_expected/cjs.js
index 0bbfe60..1968b8b 100644
--- a/test/form/multiple-exports/_expected/cjs.js
+++ b/test/form/multiple-exports/_expected/cjs.js
@@ -1,4 +1,7 @@
 'use strict';
 
-exports.foo = 1;
-exports.bar = 2;
+var foo = 1;
+var bar = 2;
+
+exports.foo = foo;
+exports.bar = bar;
diff --git a/test/form/multiple-exports/_expected/iife.js b/test/form/multiple-exports/_expected/iife.js
index 09461cb..8ed8290 100644
--- a/test/form/multiple-exports/_expected/iife.js
+++ b/test/form/multiple-exports/_expected/iife.js
@@ -1,6 +1,9 @@
 (function (exports) { 'use strict';
 
-	exports.foo = 1;
-	exports.bar = 2;
+	var foo = 1;
+	var bar = 2;
+
+	exports.foo = foo;
+	exports.bar = bar;
 
 })((this.myBundle = {}));
diff --git a/test/form/multiple-exports/_expected/umd.js b/test/form/multiple-exports/_expected/umd.js
index 2fd0eb7..687b75c 100644
--- a/test/form/multiple-exports/_expected/umd.js
+++ b/test/form/multiple-exports/_expected/umd.js
@@ -4,7 +4,10 @@
 	factory((global.myBundle = {}));
 }(this, function (exports) { 'use strict';
 
-	exports.foo = 1;
-	exports.bar = 2;
+	var foo = 1;
+	var bar = 2;
+
+	exports.foo = foo;
+	exports.bar = bar;
 
 }));
diff --git a/test/form/preserves-comments-after-imports/_expected/amd.js b/test/form/preserves-comments-after-imports/_expected/amd.js
index fd4591b..82a0a52 100644
--- a/test/form/preserves-comments-after-imports/_expected/amd.js
+++ b/test/form/preserves-comments-after-imports/_expected/amd.js
@@ -4,6 +4,8 @@ define(['exports'], function (exports) { 'use strict';
 	var number = 5;
 
 	/** A comment for obj */
-	exports.obj = { number };
+	var obj = { number };
+
+	exports.obj = obj;
 
 });
diff --git a/test/form/preserves-comments-after-imports/_expected/cjs.js b/test/form/preserves-comments-after-imports/_expected/cjs.js
index 86e64c1..8b15cd1 100644
--- a/test/form/preserves-comments-after-imports/_expected/cjs.js
+++ b/test/form/preserves-comments-after-imports/_expected/cjs.js
@@ -4,4 +4,6 @@
 var number = 5;
 
 /** A comment for obj */
-exports.obj = { number };
+var obj = { number };
+
+exports.obj = obj;
diff --git a/test/form/preserves-comments-after-imports/_expected/iife.js b/test/form/preserves-comments-after-imports/_expected/iife.js
index 02f5255..9da8252 100644
--- a/test/form/preserves-comments-after-imports/_expected/iife.js
+++ b/test/form/preserves-comments-after-imports/_expected/iife.js
@@ -4,6 +4,8 @@
 	var number = 5;
 
 	/** A comment for obj */
-	exports.obj = { number };
+	var obj = { number };
+
+	exports.obj = obj;
 
 })((this.myBundle = {}));
diff --git a/test/form/preserves-comments-after-imports/_expected/umd.js b/test/form/preserves-comments-after-imports/_expected/umd.js
index 6993070..96fec25 100644
--- a/test/form/preserves-comments-after-imports/_expected/umd.js
+++ b/test/form/preserves-comments-after-imports/_expected/umd.js
@@ -8,6 +8,8 @@
 	var number = 5;
 
 	/** A comment for obj */
-	exports.obj = { number };
+	var obj = { number };
+
+	exports.obj = obj;
 
 }));
diff --git a/test/function/assignment-to-exports/_config.js b/test/function/assignment-to-exports/_config.js
index c958adb..fac0cb3 100644
--- a/test/function/assignment-to-exports/_config.js
+++ b/test/function/assignment-to-exports/_config.js
@@ -6,5 +6,6 @@ module.exports = {
 		assert.equal( exports.count, 0 );
 		exports.incr();
 		assert.equal( exports.count, 1 );
-	}
+	},
+	// solo: true
 };