for...to excludes the upper bound. Fixes #275.

3 files changed, 33 insertions, 2 deletions

diff --git a/scss/compiler.py b/scss/compiler.py
index 23b9487..942de82 100644
--- a/scss/compiler.py
+++ b/scss/compiler.py
@@ -941,7 +941,10 @@ class Compilation(object):
         """
         var, _, name = block.argument.partition(' from ')
         frm, _, through = name.partition(' through ')
-        if not through:
+        if through:
+            inclusive = True
+        else:
+            inclusive = False
             frm, _, through = frm.partition(' to ')
         frm = calculator.calculate(frm)
         through = calculator.calculate(through)
@@ -967,7 +970,9 @@ class Compilation(object):
             # DEVIATION: Allow not creating a new namespace
             inner_rule.namespace = rule.namespace
 
-        for i in rev(range(frm, through + 1)):
+        if inclusive:
+            through += 1
+        for i in rev(range(frm, through)):
             inner_rule.namespace.set_variable(var, Number(i))
             self.manage_children(inner_rule, scope)
 
diff --git a/scss/tests/files/bugs/for-to-vs-through.css b/scss/tests/files/bugs/for-to-vs-through.css
new file mode 100644
index 0000000..3d50671
--- /dev/null
+++ b/scss/tests/files/bugs/for-to-vs-through.css
@@ -0,0 +1,14 @@
+a {
+  prop: 1;
+  prop: 2;
+  prop: 3;
+  prop: 4;
+}
+
+b {
+  prop: 1;
+  prop: 2;
+  prop: 3;
+  prop: 4;
+  prop: 5;
+}
diff --git a/scss/tests/files/bugs/for-to-vs-through.scss b/scss/tests/files/bugs/for-to-vs-through.scss
new file mode 100644
index 0000000..c5af514
--- /dev/null
+++ b/scss/tests/files/bugs/for-to-vs-through.scss
@@ -0,0 +1,12 @@
+// `to` excludes the upper bound, but `through` does not
+a {
+    @for $var from 1 to 5 {
+        prop: $var;
+    }
+}
+
+b {
+    @for $var from 1 through 5 {
+        prop: $var;
+    }
+}