Merge pull request #116 from holidayextras/flow

Use Flow for some Static Analysis

Author: Oliver Rumbelow

.flowconfig

@@ -0,0 +1,10 @@
+[include]
+./lib/
+
+[ignore]
+.*bad-locale\.json
+
+[options]
+module.ignore_non_literal_requires=true
+munge_underscores=true
+suppress_comment= \\(.\\|\n\\)*\\$FlowFixMe

.travis.yml

@@ -5,6 +5,7 @@ script: "npm run $TEST_STEP"
 env:
   matrix:
     - TEST_STEP=lint
+    - TEST_STEP=flow
     - TEST_STEP=test
 notifications:
   email: false

CONTRIBUTING.md

@@ -26,6 +26,11 @@ To verify all the code changes pass our style guidelines:
 npm run lint
 ```
 
+To run the static analysis tool (provided by Flow):
+```
+npm run flow
+```
+
 To verify everything still behaves as expected:
 ```
 npm test

lib/MemoryHandler.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 var _ = {
   assign: require("lodash.assign")

lib/debugging.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 module.exports = {
   handler: {

lib/handlerEnforcer.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 var handlerEnforcer = module.exports = { };
 
@@ -12,6 +13,10 @@ handlerEnforcer.wrap = function(handlers) {
 };
 
 handlerEnforcer._wrapHandler = function(handlers, operation, outCount) {
+  if (typeof outCount !== "number") {
+    throw new Error("Invalid use of handlerEnforcer._wrapHandler!");
+  }
+
   var original = handlers[operation];
   return function() {
     var argsIn = Array.prototype.slice.call(arguments);
@@ -20,6 +25,7 @@ handlerEnforcer._wrapHandler = function(handlers, operation, outCount) {
     argsIn.push(function() {
       var argsOut = Array.prototype.slice.call(arguments);
       argsOut = argsOut.slice(0, outCount);
+      // $FlowFixMe: We've already ruled out any other possible types for outCount?
       while (argsOut.length < outCount) {
         argsOut.push(null);
       }

lib/jsonApi.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 var jsonApi = module.exports = { };
 jsonApi._resources = { };

lib/ourJoi.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 var ourJoi = module.exports = { };
 

lib/pagination.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 var pagination = module.exports = { };
 

lib/postProcess.js

@@ -1,3 +1,4 @@
+/* @flow weak */
 "use strict";
 var postProcess = module.exports = { };
 
@@ -69,6 +70,8 @@ postProcess._fetchRelatedResources = function(request, mainResource, callback) {
         json = null;
       }
 
+      if (!json) return done(null, [ ]);
+
       if (externalRes.statusCode >= 400) {
         return done(json.errors);
       }