Correctly render function expression inside simplified expression sta…

…tements. (#2696)

Resolves #2684

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, ')');
+		}
+	}
 }

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'
+};

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');