feat: support pre-parsed queries (eg. graphql-tag)

index.d.ts

@@ -196,7 +196,7 @@ declare namespace mercurius {
       TData extends Record<string, any> = Record<string, any>,
       TVariables extends Record<string, any> = Record<string, any>
     >(
-      source: string,
+      source: string | DocumentNode,
       context?: Record<string, any>,
       variables?: TVariables,
       operationName?: string
@@ -737,7 +737,7 @@ declare module 'fastify' {
       TData extends Record<string, any> = Record<string, any>,
       TVariables extends Record<string, any> = Record<string, any>
     >(
-      source: string,
+      source: string | DocumentNode,
       context?: Record<string, any>,
       variables?: TVariables,
       operationName?: string

index.js

@@ -1,7 +1,6 @@
 'use strict'
 
 const fp = require('fastify-plugin')
-const LRU = require('tiny-lru').lru
 const routes = require('./lib/routes')
 const { compileQuery, isCompiledQuery } = require('graphql-jit')
 const { Factory } = require('single-user-cache')
@@ -46,7 +45,7 @@ const {
   onExtendSchemaHandler
 } = require('./lib/handlers')
 
-function buildCache (opts) {
+async function buildCache (opts) {
   if (Object.prototype.hasOwnProperty.call(opts, 'cache')) {
     const isBoolean = typeof opts.cache === 'boolean'
     const isNumber = typeof opts.cache === 'number'
@@ -55,20 +54,22 @@ function buildCache (opts) {
       // no cache
       return null
     } else if (isNumber) {
+      const QuickLRU = (await import('quick-lru')).default
       // cache size as specified
-      return LRU(opts.cache)
+      return new QuickLRU({ maxSize: opts.cache })
     } else if (!isBoolean && !isNumber) {
       throw new MER_ERR_INVALID_OPTS('Cache type is not supported')
     }
   }
 
+  const QuickLRU = (await import('quick-lru')).default
   // default cache, 1024 entries
-  return LRU(1024)
+  return new QuickLRU({ maxSize: 1024 })
 }
 
 const mercurius = fp(async function (app, opts) {
-  const lru = buildCache(opts)
-  const lruErrors = buildCache(opts)
+  const lru = await buildCache(opts)
+  const lruErrors = await buildCache(opts)
 
   if (lru && opts.validationRules && typeof opts.validationRules === 'function') {
     throw new MER_ERR_INVALID_OPTS('Using a function for the validationRules is incompatible with query caching')
@@ -413,7 +414,7 @@ const mercurius = fp(async function (app, opts) {
     const reply = context.reply
 
     // Trigger preParsing hook
-    if (context.preParsing !== null) {
+    if (context.preParsing !== null && typeof source === 'string') {
       await preParsingHandler({ schema: fastifyGraphQl.schema, source, context })
     }
 
@@ -433,7 +434,9 @@ const mercurius = fp(async function (app, opts) {
       }
 
       try {
-        document = parse(source, gqlParseOpts)
+        document = typeof source === 'string'
+          ? parse(source, gqlParseOpts)
+          : structuredClone(source)
       } catch (syntaxError) {
         try {
           // Do not try to JSON.parse maxToken exceeded validation errors

package.json

@@ -41,6 +41,7 @@
     "eslint": "^9.9.1",
     "fastify": "^4.17.0",
     "graphql": "^16.0.0",
+    "graphql-tag": "^2.12.6",
     "graphql-ws": "^5.11.2",
     "neostandard": "^0.11.4",
     "pre-commit": "^1.2.2",
@@ -61,6 +62,7 @@
     "graphql-jit": "0.8.4",
     "mqemitter": "^5.0.0",
     "p-map": "^4.0.0",
+    "quick-lru": "^7.0.0",
     "readable-stream": "^4.0.0",
     "safe-stable-stringify": "^2.3.0",
     "secure-json-parse": "^2.7.0",

test/app-decorator.js

@@ -4,6 +4,7 @@ const { test } = require('tap')
 const Fastify = require('fastify')
 const GQL = require('..')
 const { GraphQLError } = require('graphql')
+const gql = require('graphql-tag')
 
 const {
   GraphQLScalarType,
@@ -1439,3 +1440,33 @@ test('defineResolvers should support __resolveReference', async (t) => {
   // needed so that graphql is defined
   await app.ready()
 })
+
+test('graphql-tag', async (t) => {
+  const app = Fastify()
+  const schema = `
+    type Query {
+      add(x: Int, y: Int): Int
+    }
+  `
+
+  const resolvers = {
+    add: async ({ x, y }) => x + y
+  }
+
+  app.register(GQL, {
+    schema,
+    resolvers
+  })
+
+  // needed so that graphql is defined
+  await app.ready()
+
+  const query = gql`{ add(x: 2, y: 2) }`
+  const res = await app.graphql(query)
+
+  t.same(res, {
+    data: {
+      add: 4
+    }
+  })
+})