Merge pull request #241 from kachkaev/schema-directives-example

Replace custom-directives with schema-directives example

Author: schickling

examples/custom-directives/index.js

@@ -1,14 +1,14 @@
 # custom-directive
 
-This directory contains a simple GraphQL with custom directives example based on `graphql-yoga`.
+This directory contains a simple GraphQL with [schema directives](https://www.apollographql.com/docs/graphql-tools/schema-directives.html) example based on `graphql-yoga`.
 
 ## Get started
 
 **Clone the repository:**
 
 ```sh
 git clone https://github.com/graphcool/graphql-yoga.git
-cd graphql-yoga/examples/custom-directives
+cd graphql-yoga/examples/schema-directives
 ```
 
 **Install dependencies and run the app:**
@@ -43,6 +43,7 @@ The server returns the following response:
 Note that the original `Hello Word` output from the resolver is now in upper case due to our custom `@upper` directive.
 
 **Query `secret` (with role set as `admin`):**
+
 ```graphql
 query {
   secret
@@ -59,10 +60,9 @@ The server returns the following response:
 }
 ```
 
-
 **Query `secret` (with role set as `user`):**
 
-Go to `index.js:45`, change `admin` by `user` and reload the server.
+Go to `index.js:64`, change `admin` by `user` and reload the server.
 
 ```graphql
 query {
@@ -82,13 +82,11 @@ The server returns the following response:
       "message": "You are not authorized. Expected roles: admin",
       "locations": [
         {
-          "line": 1,
-          "column": 2
+          "line": 2,
+          "column": 3
         }
       ],
-      "path": [
-        "secret"
-      ]
+      "path": ["secret"]
     }
   ]
 }

examples/custom-directives/README.md renamed to examples/schema-directives/README.md

@@ -0,0 +1,67 @@
+const { GraphQLServer } = require('graphql-yoga')
+const { SchemaDirectiveVisitor } = require('graphql-tools')
+const { defaultFieldResolver } = require('graphql')
+
+const typeDefs = `
+  directive @upper on FIELD_DEFINITION
+  directive @auth(roles: [String]) on FIELD_DEFINITION
+
+  type Query {
+    hello: String! @upper
+    secret: String @auth(roles: ["admin"])
+  }
+`
+
+class UpperDirective extends SchemaDirectiveVisitor {
+  visitFieldDefinition(field) {
+    const { resolve = defaultFieldResolver } = field
+    field.resolve = async function(...args) {
+      const result = await resolve.apply(this, args)
+      if (typeof result === 'string') {
+        return result.toUpperCase()
+      }
+      return result
+    }
+  }
+}
+
+class AuthDirective extends SchemaDirectiveVisitor {
+  visitFieldDefinition(field) {
+    const { resolve = defaultFieldResolver } = field
+    const { roles: expectedRoles = [] } = this.args
+    field.resolve = (...args) => {
+      const [, , context] = args
+      if (
+        expectedRoles.length === 0 ||
+        expectedRoles.some(r => context.roles.includes(r))
+      ) {
+        // Call original resolver if role check has passed
+        return resolve.apply(this, args)
+      }
+
+      // We has two options here. throw an error or return null (if field is nullable).
+      throw new Error(
+        `You are not authorized. Expected roles: ${expectedRoles.join(', ')}`,
+      )
+    }
+  }
+}
+
+const resolvers = {
+  Query: {
+    hello: () => `Hello World`,
+    secret: () => `This is very secret`,
+  },
+}
+
+const server = new GraphQLServer({
+  typeDefs,
+  resolvers,
+  schemaDirectives: {
+    upper: UpperDirective,
+    auth: AuthDirective,
+  },
+  context: () => ({ roles: ['admin'] }),
+})
+
+server.start(() => console.log('Server is running on localhost:4000'))

examples/schema-directives/index.js

@@ -3,6 +3,6 @@
     "start": "node ."
   },
   "dependencies": {
-    "graphql-yoga": "1.6.0"
+    "graphql-yoga": "^1.7.1"
   }
 }