prevent illegal reassignments, part 2

src/Statement.js

@@ -105,38 +105,41 @@ export default class Statement {
 					return this.skip();
 				}
 
-				if ( isReference( node, parent ) ) {
-					const reference = new Reference( node, scope );
-					references.push( reference );
+				let isReassignment;
 
-					if ( parent.type in modifierNodes ) {
-						let subject = parent[ modifierNodes[ parent.type ] ];
-						let depth = 0;
+				if ( parent && parent.type in modifierNodes ) {
+					let subject = parent[ modifierNodes[ parent.type ] ];
+					let depth = 0;
 
-						while ( subject.type === 'MemberExpression' ) {
-							subject = subject.object;
-							depth += 1;
-						}
+					while ( subject.type === 'MemberExpression' ) {
+						subject = subject.object;
+						depth += 1;
+					}
 
-						const importDeclaration = module.imports[ subject.name ];
+					const importDeclaration = module.imports[ subject.name ];
 
-						if ( !scope.contains( subject.name ) && importDeclaration ) {
-							const minDepth = importDeclaration.name === '*' ?
-								2 : // cannot do e.g. `namespace.foo = bar`
-								1;  // cannot do e.g. `foo = bar`, but `foo.bar = bar` is fine
+					if ( !scope.contains( subject.name ) && importDeclaration ) {
+						const minDepth = importDeclaration.name === '*' ?
+							2 : // cannot do e.g. `namespace.foo = bar`
+							1;  // cannot do e.g. `foo = bar`, but `foo.bar = bar` is fine
 
-							if ( depth < minDepth ) {
-								const err = new Error( `Illegal reassignment to import '${subject.name}'` );
-								err.file = module.id;
-								err.loc = getLocation( module.magicString.toString(), subject.start );
-								throw err;
-							}
+						if ( depth < minDepth ) {
+							const err = new Error( `Illegal reassignment to import '${subject.name}'` );
+							err.file = module.id;
+							err.loc = getLocation( module.magicString.toString(), subject.start );
+							throw err;
 						}
-
-						reference.isReassignment = !depth;
 					}
 
+					isReassignment = !depth;
+				}
+
+				if ( isReference( node, parent ) ) {
+					const reference = new Reference( node, scope );
+					references.push( reference );
+
 					reference.isImmediatelyUsed = !readDepth;
+					reference.isReassignment = isReassignment;
 
 					this.skip(); // don't descend from `foo.bar.baz` into `foo.bar`
 				}