Add test case for syntax error formatting

Author: andreypopp

test/helpers.js

@@ -69,6 +69,23 @@ exports.test = function test(name, input, result, query, modules) {
 	});
 };
 
+exports.testError = function test(name, input, onError) {
+	it(name, function(done) {
+    runLoader(cssLoader, input, undefined, {}, function(err, output) {
+      if (!err) {
+        done(new Error('Expected error to be thrown'));
+      } else {
+        try {
+          onError(err);
+        } catch (error) {
+          return done(error);
+        }
+        done();
+      }
+		});
+	});
+};
+
 exports.testWithMap = function test(name, input, map, result, query, modules) {
 	it(name, function(done) {
 		runLoader(cssLoader, input, map, {

test/simpleTest.js

@@ -1,6 +1,8 @@
 /*globals describe */
 
+var assert = require('assert');
 var test = require("./helpers").test;
+var testError = require("./helpers").testError;
 var testMinimize = require("./helpers").testMinimize;
 
 describe("simple", function() {
@@ -19,4 +21,15 @@ describe("simple", function() {
 	testMinimize("minimized simple", ".class { a: b c d; }", [
 		[1, ".class{a:b c d}", ""]
 	]);
+  testError("error formatting", ".some {\n invalid css;\n}", function(err) {
+    assert.equal(err.message, [
+      'Unknown word (2:2)',
+      '',
+      '  1 | .some {',
+      '> 2 |  invalid css;',
+      '    |  ^',
+      '  3 | }',
+      '',
+    ].join('\n'));
+  });
 });