Make sure unused default exports are deconflicted when tree-shaking i…

…s false (#2758)

src/ast/nodes/ExportDefaultDeclaration.ts

@@ -46,6 +46,13 @@ export default class ExportDefaultDeclaration extends NodeBase {
 	variable: ExportDefaultVariable;
 	private declarationName: string;
 
+	include(includeAllChildrenRecursively: boolean) {
+		super.include(includeAllChildrenRecursively);
+		if (includeAllChildrenRecursively) {
+			this.context.includeVariable(this.variable);
+		}
+	}
+
 	initialise() {
 		this.included = false;
 		this.declarationName =

test/form/samples/no-treeshake-default-export-conflict/_config.js

@@ -0,0 +1,6 @@
+module.exports = {
+	description: 'properly deconflicts default exports when not tree-shaking',
+	options: {
+		treeshake: false
+	}
+};

test/form/samples/no-treeshake-default-export-conflict/_expected.js

@@ -0,0 +1,7 @@
+function foo() {
+	return 'foo';
+}
+
+function foo$1() {
+	return 'default';
+}

test/form/samples/no-treeshake-default-export-conflict/foo.js

@@ -0,0 +1,7 @@
+export function foo() {
+	return 'foo';
+}
+
+export default function() {
+	return 'default';
+}

test/form/samples/no-treeshake-default-export-conflict/main.js

@@ -0,0 +1 @@
+import './foo';