[requires] add tests for requires.io service, review error handling (#1361)

lib/error-helper.js

@@ -0,0 +1,23 @@
+'use strict';
+
+const checkErrorResponse = function(badgeData, err, res) {
+  if (err != null) {
+    badgeData.text[1] = 'inaccessible';
+    badgeData.colorscheme = 'red';
+    return true;
+  } else if (res.statusCode === 404) {
+    badgeData.text[1] = 'not found';
+    badgeData.colorscheme = 'lightgrey';
+    return true;
+  } else if (res.statusCode !== 200) {
+    badgeData.text[1] = 'invalid';
+    badgeData.colorscheme = 'lightgrey';
+    return true;
+  } else {
+    return false;
+  }
+};
+
+module.exports = {
+  checkErrorResponse,
+};