refactor(infra): directory structure (#4615)

packages/backend/server/src/graphql/logger-plugin.ts

@@ -0,0 +1,48 @@
+import {
+  ApolloServerPlugin,
+  GraphQLRequestContext,
+  GraphQLRequestListener,
+} from '@apollo/server';
+import { Plugin } from '@nestjs/apollo';
+import { Logger } from '@nestjs/common';
+import { Response } from 'express';
+
+import { Metrics } from '../metrics/metrics';
+import { ReqContext } from '../types';
+
+@Plugin()
+export class GQLLoggerPlugin implements ApolloServerPlugin {
+  protected logger = new Logger(GQLLoggerPlugin.name);
+
+  constructor(private readonly metrics: Metrics) {}
+
+  requestDidStart(
+    reqContext: GraphQLRequestContext<ReqContext>
+  ): Promise<GraphQLRequestListener<GraphQLRequestContext<ReqContext>>> {
+    const res = reqContext.contextValue.req.res as Response;
+    const operation = reqContext.request.operationName;
+
+    this.metrics.gqlRequest(1, { operation });
+    const timer = this.metrics.gqlTimer({ operation });
+
+    return Promise.resolve({
+      willSendResponse: () => {
+        const costInMilliseconds = timer() * 1000;
+        res.setHeader(
+          'Server-Timing',
+          `gql;dur=${costInMilliseconds};desc="GraphQL"`
+        );
+        return Promise.resolve();
+      },
+      didEncounterErrors: () => {
+        this.metrics.gqlError(1, { operation });
+        const costInMilliseconds = timer() * 1000;
+        res.setHeader(
+          'Server-Timing',
+          `gql;dur=${costInMilliseconds};desc="GraphQL ${operation}"`
+        );
+        return Promise.resolve();
+      },
+    });
+  }
+}