Make sure object prototype methods are not considered to be falsy (#2652

)
rollup · Jan 19, 2019 · cb3829b · cb3829b
1 parent 1633675
commit cb3829b
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Showing 3 changed files with 15 additions and 6 deletions.
diff --git a/src/ast/nodes/ObjectExpression.ts b/src/ast/nodes/ObjectExpression.ts
@@ -78,6 +78,7 @@ export default class ObjectExpression extends NodeBase {
 		if (
 			path.length === 1 &&
 			!this.propertyMap[key] &&
+			!objectMembers[key] &&
 			this.unmatchablePropertiesRead.length === 0
 		) {
 			if (!this.expressionsToBeDeoptimized[key]) {
@@ -167,8 +168,8 @@ export default class ObjectExpression extends NodeBase {
 		for (const property of typeof key !== 'string'
 			? this.properties
 			: this.propertyMap[key]
-				? this.propertyMap[key].propertiesRead
-				: []) {
+			? this.propertyMap[key].propertiesRead
+			: []) {
 			if (property.hasEffectsWhenAccessedAtPath(subPath, options)) return true;
 		}
 		return false;
@@ -191,10 +192,10 @@ export default class ObjectExpression extends NodeBase {
 		for (const property of typeof key !== 'string'
 			? this.properties
 			: path.length > 1
-				? this.propertyMap[key].propertiesRead
-				: this.propertyMap[key]
-					? this.propertyMap[key].propertiesSet
-					: []) {
+			? this.propertyMap[key].propertiesRead
+			: this.propertyMap[key]
+			? this.propertyMap[key].propertiesSet
+			: []) {
 			if (property.hasEffectsWhenAssignedAtPath(subPath, options)) return true;
 		}
 		return false;

diff --git a/test/function/samples/builtin-prototypes/truthiness/_config.js b/test/function/samples/builtin-prototypes/truthiness/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'regards builtin methods as truthy in objects'
+};
diff --git a/test/function/samples/builtin-prototypes/truthiness/main.js b/test/function/samples/builtin-prototypes/truthiness/main.js
@@ -0,0 +1,5 @@
+if (!{}.hasOwnProperty) {
+	throw new Error('Prototype method evaluated as falsy');
+}
+
+assert.strictEqual({}.hasOwnProperty ? true : false, true);