From 14a17af81b5174c399ee285dd49f11488dbe47d8 Mon Sep 17 00:00:00 2001
From: Lukas Taegert-Atkinson <lukastaegert@users.noreply.github.com>
Date: Sun, 17 Feb 2019 08:05:26 +0100
Subject: [PATCH] Correctly render function expression inside simplified
 expression statements. (#2696)

Resolves #2684
---
 src/ast/nodes/CallExpression.ts               | 18 ++++++
 .../_config.js                                |  3 +
 .../main.js                                   | 58 +++++++++++++++++++
 3 files changed, 79 insertions(+)
 create mode 100644 test/function/samples/function-expressions-simplified-to-statement/_config.js
 create mode 100644 test/function/samples/function-expressions-simplified-to-statement/main.js

diff --git a/src/ast/nodes/CallExpression.ts b/src/ast/nodes/CallExpression.ts
index 5a8dab171c4..172bd2594ef 100644
--- a/src/ast/nodes/CallExpression.ts
+++ b/src/ast/nodes/CallExpression.ts
@@ -1,3 +1,6 @@
+import MagicString from 'magic-string';
+import { BLANK } from '../../utils/blank';
+import { NodeRenderOptions, RenderOptions } from '../../utils/renderHelpers';
 import CallOptions from '../CallOptions';
 import { DeoptimizableEntity } from '../DeoptimizableEntity';
 import { ExecutionPathOptions } from '../ExecutionPathOptions';
@@ -210,4 +213,19 @@ export default class CallExpression extends NodeBase implements DeoptimizableEnt
 			this.returnExpression.deoptimizePath(path);
 		}
 	}
+
+	render(
+		code: MagicString,
+		options: RenderOptions,
+		{ renderedParentType }: NodeRenderOptions = BLANK
+	) {
+		super.render(code, options);
+		if (
+			renderedParentType === NodeType.ExpressionStatement &&
+			this.callee.type === NodeType.FunctionExpression
+		) {
+			code.appendRight(this.start, '(');
+			code.prependLeft(this.end, ')');
+		}
+	}
 }
diff --git a/test/function/samples/function-expressions-simplified-to-statement/_config.js b/test/function/samples/function-expressions-simplified-to-statement/_config.js
new file mode 100644
index 00000000000..2a43659a713
--- /dev/null
+++ b/test/function/samples/function-expressions-simplified-to-statement/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'correctly handles function expressions which are simplified to statements'
+};
diff --git a/test/function/samples/function-expressions-simplified-to-statement/main.js b/test/function/samples/function-expressions-simplified-to-statement/main.js
new file mode 100644
index 00000000000..f5f4e72e1a7
--- /dev/null
+++ b/test/function/samples/function-expressions-simplified-to-statement/main.js
@@ -0,0 +1,58 @@
+var value;
+
+// conditional expression
+function foo(){
+	value = 'foo';
+}
+
+true ? function foo(x){
+	value = x;
+}("consequent") : 2;
+
+assert.equal(value, 'consequent');
+
+foo("incorrect");
+
+assert.equal(value, 'foo');
+
+false ? null: function foo(x){
+	value = x;
+}("alternate");
+
+assert.equal(value, 'alternate');
+
+// logical expression
+function bar(){
+	value = 'bar';
+}
+
+true && function bar(x){
+	value = x;
+}("and");
+
+assert.equal(value, 'and');
+
+bar("incorrect");
+
+assert.equal(value, 'bar');
+
+false || function bar(x){
+	value = x;
+}("or");
+
+assert.equal(value, 'or');
+
+// sequence expression
+function baz(){
+	value = 'baz';
+}
+
+0, function baz(x){
+	value = x;
+}("comma");
+
+assert.equal(value, 'comma');
+
+baz("incorrect");
+
+assert.equal(value, 'baz');