Make sure pattern defaults are deconflicted correctly (#2446)

src/ast/nodes/AssignmentPattern.ts

@@ -1,3 +1,6 @@
+import MagicString from 'magic-string';
+import { BLANK } from '../../utils/blank';
+import { NodeRenderOptions, RenderOptions } from '../../utils/renderHelpers';
 import { ExecutionPathOptions } from '../ExecutionPathOptions';
 import { EMPTY_PATH, ObjectPath, UNKNOWN_PATH } from '../values';
 import * as NodeType from './NodeType';
@@ -27,4 +30,13 @@ export default class AssignmentPattern extends NodeBase implements PatternNode {
 	deoptimizePath(path: ObjectPath) {
 		path.length === 0 && this.left.deoptimizePath(path);
 	}
+
+	render(
+		code: MagicString,
+		options: RenderOptions,
+		{ isShorthandProperty }: NodeRenderOptions = BLANK
+	) {
+		this.left.render(code, options, { isShorthandProperty });
+		this.right.render(code, options);
+	}
 }

src/ast/nodes/Identifier.ts

@@ -10,9 +10,7 @@ import { ImmutableEntityPathTracker } from '../utils/ImmutableEntityPathTracker'
 import { LiteralValueOrUnknown, ObjectPath, UNKNOWN_EXPRESSION, UNKNOWN_VALUE } from '../values';
 import LocalVariable from '../variables/LocalVariable';
 import Variable from '../variables/Variable';
-import AssignmentPattern from './AssignmentPattern';
 import * as NodeType from './NodeType';
-import Property from './Property';
 import { ExpressionEntity } from './shared/Expression';
 import { Node, NodeBase } from './shared/Node';
 
@@ -146,7 +144,7 @@ export default class Identifier extends NodeBase {
 	render(
 		code: MagicString,
 		_options: RenderOptions,
-		{ renderedParentType, isCalleeOfRenderedParent }: NodeRenderOptions = BLANK
+		{ renderedParentType, isCalleeOfRenderedParent, isShorthandProperty }: NodeRenderOptions = BLANK
 	) {
 		if (this.variable) {
 			const name = this.variable.getName();
@@ -156,11 +154,7 @@ export default class Identifier extends NodeBase {
 					storeName: true,
 					contentOnly: true
 				});
-				let relevantParent = this.parent;
-				if (relevantParent.type === NodeType.AssignmentPattern) {
-					relevantParent = (<AssignmentPattern>relevantParent).parent;
-				}
-				if (relevantParent.type === NodeType.Property && (<Property>relevantParent).shorthand) {
+				if (isShorthandProperty) {
 					code.prependRight(this.start, `${this.name}: `);
 				}
 			}

src/ast/nodes/Property.ts

@@ -155,7 +155,7 @@ export default class Property extends NodeBase implements DeoptimizableEntity {
 		if (!this.shorthand) {
 			this.key.render(code, options);
 		}
-		this.value.render(code, options);
+		this.value.render(code, options, { isShorthandProperty: this.shorthand });
 	}
 
 	private updateReturnExpression() {

src/utils/renderHelpers.ts

@@ -16,6 +16,7 @@ export interface NodeRenderOptions {
 	isNoStatement?: boolean;
 	renderedParentType?: string; // also serves as a flag if the rendered parent is different from the actual parent
 	isCalleeOfRenderedParent?: boolean;
+	isShorthandProperty?: boolean;
 }
 
 export const NO_SEMICOLON: NodeRenderOptions = { isNoStatement: true };

test/form/samples/renamed-pattern-defaults/_config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'handles deconflicting of variables used as defaults in patterns (#2445)'
+};

test/form/samples/renamed-pattern-defaults/_expected.js

@@ -0,0 +1,7 @@
+const EMPTY = null;
+const {foo = EMPTY} = {};
+console.log(foo);
+
+const EMPTY$1 = null;
+const {foo: foo$1 = EMPTY$1} = {};
+console.log(foo$1);

test/form/samples/renamed-pattern-defaults/dep.js

@@ -0,0 +1,3 @@
+const EMPTY = null;
+const {foo = EMPTY} = {};
+console.log(foo);

test/form/samples/renamed-pattern-defaults/main.js

@@ -0,0 +1,5 @@
+import './dep.js';
+
+const EMPTY = null;
+const {foo = EMPTY} = {};
+console.log(foo);