From 80bd91400b6bc8167b1e42897872484b78284e6f Mon Sep 17 00:00:00 2001
From: "Anantachai Saothong (Manta)" <anantachai.s@taskworld.com>
Date: Sun, 31 Dec 2017 01:20:03 +0700
Subject: [PATCH] Fixed missing parenthesis in string interpolation

---
 edge/format.js                 | 7 +++++++
 spec/interpolation/input.styl  | 5 ++++-
 spec/interpolation/output.styl | 4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/edge/format.js b/edge/format.js
index afb6d27..50c8577 100644
--- a/edge/format.js
+++ b/edge/format.js
@@ -584,6 +584,12 @@ function format(content, options = {}) {
 					inputNode.parent.op !== '[]' &&
 					inputNode.parent.op !== '[]='
 				)
+			const parentIsStringInterpolation = (
+				inputNode.parent instanceof Stylus.nodes.BinOp &&
+				inputNode.parent.op === '%' &&
+				inputNode.parent.right === inputNode &&
+				inputNode.nodes.length > 1
+			)
 			const parentIsNestedExpression =
 				inputNode.nodes.length === 1 &&
 				inputNode.parent instanceof Stylus.nodes.Expression &&
@@ -606,6 +612,7 @@ function format(content, options = {}) {
 				inputNode.nodes[1] instanceof Stylus.nodes.Ident
 			const currentHasParenthesis =
 				parentIsArithmeticOperator ||
+				parentIsStringInterpolation ||
 				parentIsNestedExpression ||
 				currentIsDivision
 			if (currentHasParenthesis || currentHasUnitSuffix) {
diff --git a/spec/interpolation/input.styl b/spec/interpolation/input.styl
index a0214ba..c939a48 100644
--- a/spec/interpolation/input.styl
+++ b/spec/interpolation/input.styl
@@ -8,4 +8,7 @@ div:nth-child({row})
 
 mySelectors='#foo,#bar,.class1'
 {mySelectors+'.class2'}
-  display none
\ No newline at end of file
+  display none
+
+.class3
+  height 'calc(%s - %s)' % (a b)
\ No newline at end of file
diff --git a/spec/interpolation/output.styl b/spec/interpolation/output.styl
index c2e5e51..7f6c463 100644
--- a/spec/interpolation/output.styl
+++ b/spec/interpolation/output.styl
@@ -13,4 +13,8 @@ mySelectors = '#foo,#bar,.class1';
 
 {mySelectors + '.class2'} {
 	display: none;
+}
+
+.class3 {
+	height: 'calc(%s - %s)' % (a b);
 }
\ No newline at end of file