docs: added full example

examples/result-filter-replace.js

@@ -0,0 +1,67 @@
+'use strict'
+
+const Fastify = require('fastify')
+const mercurius = require('mercurius')
+const mercuriusAuth = require('..')
+
+const app = Fastify()
+
+const schema = `
+    directive @filterData (disallow: String!) on FIELD_DEFINITION
+
+    type Message {
+      message: String!
+      notes: String @filterData (disallow: "no-read-notes")
+    }
+    
+    type Query {
+      publicMessages: [Message!]
+    }
+`
+
+const messages = [
+  {
+    title: 'one',
+    message: 'acme one',
+    notes: 'acme one',
+    password: 'acme-one'
+  },
+  {
+    title: 'two',
+    message: 'acme two',
+    notes: 'acme two',
+    password: 'acme-two'
+  }
+]
+
+const resolvers = {
+  Query: {
+    publicMessages: async (parent, args, context, info) => {
+      return messages
+    }
+  }
+}
+
+app.register(mercurius, {
+  schema,
+  resolvers
+})
+
+app.register(mercuriusAuth, {
+  authContext (context) {
+    const headerValue = context.reply.request.headers['x-permission']
+    return { permission: headerValue ? headerValue.split(',') : [] }
+  },
+  async applyPolicy (authDirectiveAST, parent, args, context, info) {
+    const notNeeded = authDirectiveAST.arguments.find(arg => arg.name.value === 'disallow').value.value
+
+    return !context.auth.permission.includes(notNeeded)
+  },
+  outputPolicyErrors: {
+    enabled: false
+  },
+  filterSchema: true,
+  authDirective: 'filterData'
+})
+
+app.listen({ port: 3000 })