Properly migrate negated parenthesized expressions (#193)

Fixes #192.

Author: jathak

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 1.4.2
+
+### Division Migrator
+
+* Fix a bug where negated division could be migrated incorrectly.
+
 ## 1.4.1
 
 * Globs containing `**` should now be properly resolved when running on Node.

lib/src/migrators/division.dart

@@ -170,14 +170,16 @@ class _DivisionMigrationVisitor extends MigrationVisitor {
   /// Allows division within this parenthesized expression.
   ///
   /// If these parentheses contain a `/` operation that is migrated to a
-  /// function call, the now-unnecessary parentheses will be removed.
+  /// function call and [negated] is false, the now-unnecessary parentheses
+  /// will be removed.
   @override
-  void visitParenthesizedExpression(ParenthesizedExpression node) {
+  void visitParenthesizedExpression(ParenthesizedExpression node,
+      {bool negated = false}) {
     _withContext(() {
       var expression = node.expression;
       if (expression is BinaryOperationExpression &&
           expression.operator == BinaryOperator.dividedBy) {
-        if (_visitSlashOperation(expression)) {
+        if (_visitSlashOperation(expression) && !negated) {
           addPatch(patchDelete(node.span, end: 1));
           addPatch(patchDelete(node.span, start: node.span.length - 1));
         }
@@ -187,6 +189,19 @@ class _DivisionMigrationVisitor extends MigrationVisitor {
     }, isDivisionAllowed: true);
   }
 
+  /// Sets [_negatedParenthesized] to true when about to visit a negated
+  /// parenthesized expression.
+  @override
+  void visitUnaryOperationExpression(UnaryOperationExpression node) {
+    var operand = node.operand;
+    if (node.operator == UnaryOperator.minus &&
+        operand is ParenthesizedExpression) {
+      visitParenthesizedExpression(operand, negated: true);
+      return;
+    }
+    super.visitUnaryOperationExpression(node);
+  }
+
   /// Allows division within this return rule.
   @override
   void visitReturnRule(ReturnRule node) {

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass_migrator
-version: 1.4.1
+version: 1.4.2
 description: A tool for running migrations on Sass files
 author: Jennifer Thakar <[email protected]>
 homepage: https://github.com/sass/migrator

test/migrators/division/always_division.hrx

@@ -34,6 +34,11 @@ a {
   o: identity(6px / 3px);
   p: rgba(10, 20, 30/2, 0.5);
   q: rgb(10 20 30/2 / 0.5);
+
+  // Negation
+  r: -(4/3);
+  s: (-4/3);
+  t: -((-6/3) / -(4/2));
 }
 
 <==> output/entrypoint.scss
@@ -71,4 +76,9 @@ a {
   o: identity(math.div(6px, 3px));
   p: rgba(10, 20, math.div(30, 2), 0.5);
   q: rgb(10, 20, math.div(30, 2), 0.5);
+
+  // Negation
+  r: -(math.div(4, 3));
+  s: math.div(-4, 3);
+  t: -(math.div(math.div(-6, 3), -(math.div(4, 2))));
 }