Refactoring: Put all data validations in one place

@ulfgebhardt @mattwr18 @tirokk

Here's how I imagined the data validation middleware. If we roll our own
input validations I would suggest to put them all in one place.

@ulfgebhardt this commit is a great example of how tests can speed you
up: Since I can rely on existing tests, I don't have to check the validations
manually. With tests you can refactor with confidence! 👍

backend/src/middleware/index.js

@@ -10,14 +10,14 @@ import permissionsMiddleware from './permissionsMiddleware'
 import userMiddleware from './userMiddleware'
 import includedFieldsMiddleware from './includedFieldsMiddleware'
 import orderByMiddleware from './orderByMiddleware'
-import validUrlMiddleware from './validUrlMiddleware'
+import validationMiddleware from './validation'
 import notificationsMiddleware from './notifications'
 
 export default schema => {
   let middleware = [
     passwordMiddleware,
     dateTimeMiddleware,
-    validUrlMiddleware,
+    validationMiddleware,
     sluggifyMiddleware,
     excerptMiddleware,
     notificationsMiddleware,

backend/src/middleware/userMiddleware.js

@@ -1,5 +1,4 @@
 import dotenv from 'dotenv'
-import { UserInputError } from 'apollo-server'
 
 import createOrUpdateLocations from './nodes/locations'
 
@@ -13,13 +12,9 @@ export default {
       return result
     },
     UpdateUser: async (resolve, root, args, context, info) => {
-      const USERNAME_MIN_LENGTH = 3 // TODO move to the correct place
-      if (!args.name || args.name.length < USERNAME_MIN_LENGTH) {
-        throw new UserInputError(`Username must be at least ${USERNAME_MIN_LENGTH} characters long!`)
-      }
       const result = await resolve(root, args, context, info)
       await createOrUpdateLocations(args.id, args.locationName, context.driver)
       return result
-    }
+    },
   }
 }

backend/src/middleware/userMiddleware.spec.js

@@ -71,7 +71,8 @@ describe('userMiddleware', () => {
 
     it('with too short name', async () => {
       const variables = {
-        id: 'u1'
+        id: 'u1',
+        name: '  '
       }
       const expected = 'Username must be at least 3 characters long!'
       await expect(client.request(mutation, variables))

backend/src/middleware/validUrlMiddleware.js

@@ -1,18 +0,0 @@
-const validURL = str => {
-  const isValid = str.match(/^(?:https?:\/\/)(?:[^@\n])?(?:www\.)?([^:/\n?]+)/g)
-  return !!isValid
-}
-
-export default {
-  Mutation: {
-    CreateSocialMedia: async (resolve, root, args, context, info) => {
-      let socialMedia
-      if (validURL(args.url)) {
-        socialMedia = await resolve(root, args, context, info)
-      } else {
-        throw Error('Input is not a URL')
-      }
-      return socialMedia
-    }
-  }
-}

backend/src/middleware/validation/index.js

@@ -0,0 +1,30 @@
+import { UserInputError } from 'apollo-server'
+
+const USERNAME_MIN_LENGTH = 3
+
+const validateUsername = async (resolve, root, args, context, info) => {
+  if (args.name && args.name.length >= USERNAME_MIN_LENGTH) {
+    return await resolve(root, args, context, info)
+  } else {
+    throw new UserInputError(`Username must be at least ${USERNAME_MIN_LENGTH} characters long!`)
+  }
+}
+
+const validateUrl = async (resolve, root, args, context, info) => {
+  const { url } = args
+  const isValid = url.match(/^(?:https?:\/\/)(?:[^@\n])?(?:www\.)?([^:/\n?]+)/g)
+  if (isValid) {
+    return await resolve(root, args, context, info)
+  } else {
+    throw new UserInputError('Input is not a URL')
+  }
+}
+
+export default {
+  Mutation: {
+    // CreateUser: validateUsername,
+    UpdateUser: validateUsername,
+    CreateSocialMedia: validateUrl
+  }
+}
+