passing foo to a function cannot rebind foo

src/Statement.js

@@ -146,7 +146,7 @@ export default class Statement {
 	}
 
 	checkForWrites ( scope, node ) {
-		const addNode = ( node, disallowImportReassignments ) => {
+		const addNode = ( node, isAssignment ) => {
 			let depth = 0; // determine whether we're illegally modifying a binding or namespace
 
 			while ( node.type === 'MemberExpression' ) {
@@ -155,7 +155,7 @@ export default class Statement {
 			}
 
 			// disallow assignments/updates to imported bindings and namespaces
-			if ( disallowImportReassignments ) {
+			if ( isAssignment ) {
 				const importSpecifier = this.module.imports[ node.name ];
 
 				if ( importSpecifier && !scope.contains( node.name ) ) {
@@ -170,22 +170,22 @@ export default class Statement {
 						throw err;
 					}
 				}
+
+				// special case = `export default foo; foo += 1;` - we'll
+				// need to assign a new variable so that the exported
+				// value is not updated by the second statement
+				if ( this.module.exports.default && depth === 0 && this.module.exports.default.identifier === node.name ) {
+					// but only if this is a) inside a function body or
+					// b) after the export declaration
+					if ( !!scope.parent || node.start > this.module.exports.default.statement.node.start ) {
+						this.module.exports.default.isModified = true;
+					}
+				}
 			}
 
 			if ( node.type === 'Identifier' ) {
 				this.modifies[ node.name ] = true;
 			}
-
-			// special case = `export default foo; foo += 1;` - we'll
-			// need to assign a new variable so that the exported
-			// value is not updated by the second statement
-			if ( this.module.exports.default && depth === 0 && this.module.exports.default.identifier === node.name ) {
-				// but only if this is a) inside a function body or
-				// b) after the export declaration
-				if ( !!scope.parent || node.start > this.module.exports.default.statement.node.start ) {
-					this.module.exports.default.isModified = true;
-				}
-			}
 		};
 
 		if ( node.type === 'AssignmentExpression' ) {

test/form/unmodified-default-exports-function-argument/_config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'passing unbound default export to function cannot rebind it'
+};

test/form/unmodified-default-exports-function-argument/_expected/amd.js

@@ -0,0 +1,14 @@
+define(function () { 'use strict';
+
+	var foo = function () {
+		return 42;
+	};
+
+	function bar () {
+		return contrivedExample( foo );
+	}
+
+	var answer = foo();
+	var somethingElse = bar();
+
+});

test/form/unmodified-default-exports-function-argument/_expected/cjs.js

@@ -0,0 +1,12 @@
+'use strict';
+
+var foo = function () {
+	return 42;
+};
+
+function bar () {
+	return contrivedExample( foo );
+}
+
+var answer = foo();
+var somethingElse = bar();

test/form/unmodified-default-exports-function-argument/_expected/es6.js

@@ -0,0 +1,10 @@
+var foo = function () {
+	return 42;
+};
+
+function bar () {
+	return contrivedExample( foo );
+}
+
+var answer = foo();
+var somethingElse = bar();

test/form/unmodified-default-exports-function-argument/_expected/iife.js

@@ -0,0 +1,14 @@
+(function () { 'use strict';
+
+	var foo = function () {
+		return 42;
+	};
+
+	function bar () {
+		return contrivedExample( foo );
+	}
+
+	var answer = foo();
+	var somethingElse = bar();
+
+})();

test/form/unmodified-default-exports-function-argument/_expected/umd.js

@@ -0,0 +1,18 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	factory();
+}(this, function () { 'use strict';
+
+	var foo = function () {
+		return 42;
+	};
+
+	function bar () {
+		return contrivedExample( foo );
+	}
+
+	var answer = foo();
+	var somethingElse = bar();
+
+}));

test/form/unmodified-default-exports-function-argument/foo.js

@@ -0,0 +1,9 @@
+var foo = function () {
+	return 42;
+};
+
+export default foo;
+
+export function bar () {
+	return contrivedExample( foo );
+}

test/form/unmodified-default-exports-function-argument/main.js

@@ -0,0 +1,4 @@
+import foo, { bar } from './foo';
+
+var answer = foo();
+var somethingElse = bar();

test/form/unmodified-default-exports/_config.js

@@ -1,4 +1,3 @@
 module.exports = {
-	description: 'does not treat property assignment as rebinding for sake of unbound default exports',
+	description: 'does not treat property assignment as rebinding for sake of unbound default exports'
-	// solo: true
 };