Add a test case for calc and strictMath.

Gruntfile.js

@@ -212,6 +212,13 @@ module.exports = function(grunt) {
           'tmp/customFunctions.css': ['test/fixtures/customFunctions.less']
         }
       },
+      calc: {
+        options: {
+          strictMath: true
+        },
+        src: 'test/fixtures/calc.less',
+        dest: 'tmp/calc.css'
+      },
       modifyVars: {
         options: {
           modifyVars: {

test/expected/calc.css

@@ -0,0 +1,3 @@
+.a {
+  padding-top: calc(var(--header-height) + 1rem);
+}

test/fixtures/calc.less

@@ -0,0 +1,3 @@
+.a {
+  padding-top: calc(var(--header-height) + 1rem);
+}

test/less_test.js

@@ -151,6 +151,15 @@ exports.less = {
 
     test.done();
   },
+  calc: function(test) {
+    test.expect(1);
+
+    var actual = read('tmp/calc.css');
+    var expected = read('test/expected/calc.css');
+    test.equal(expected, actual, 'should process calc function with `strictMath`');
+
+    test.done();
+  },
   customFunctions: function(test) {
     test.expect(1);