sample(): add plugin and directive example (graphql)

Author: kamilmysliwiec

sample/12-graphql-schema-first/package-lock.json

@@ -21,8 +21,9 @@
   "dependencies": {
     "@nestjs/common": "6.11.8",
     "@nestjs/core": "6.11.8",
-    "@nestjs/graphql": "6.6.2",
+    "@nestjs/graphql": "^7.0.0-next.5",
     "@nestjs/platform-express": "6.11.8",
+    "apollo-server": "2.11.0",
     "apollo-server-express": "2.10.1",
     "class-transformer": "0.2.3",
     "class-validator": "0.11.0",

sample/12-graphql-schema-first/package.json

@@ -0,0 +1,15 @@
+import { SchemaDirectiveVisitor } from 'apollo-server';
+import { defaultFieldResolver, GraphQLField } from 'graphql';
+
+export class UpperCaseDirective extends SchemaDirectiveVisitor {
+  visitFieldDefinition(field: GraphQLField<any, any>) {
+    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;
+    };
+  }
+}

sample/12-graphql-schema-first/src/common/directives/upper-case.directive.ts

@@ -0,0 +1,17 @@
+import { Plugin } from '@nestjs/graphql';
+import {
+  ApolloServerPlugin,
+  GraphQLRequestListener,
+} from 'apollo-server-plugin-base';
+
+@Plugin()
+export class LoggingPlugin implements ApolloServerPlugin {
+  requestDidStart(): GraphQLRequestListener {
+    console.log('Request started');
+    return {
+      willSendResponse() {
+        console.log('Will send response');
+      },
+    };
+  }
+}