Improve the dev and demo experience by aligning with ApolloServer reg…

…arding when to enable introspection and the playground by default. (#170)

https://www.apollographql.com/docs/apollo-server/testing/graphql-playground/#enabling-graphql-playground-in-production
Conservative when NODE_ENV = production, requiring explicit selection, sensible defaults in development mode.

src/__test__/Server.test.ts

@@ -63,7 +63,7 @@ describe('Server', () => {
       afterEach(() => {
         httpServer.close()
       })
-      it('is returns data for all valid queries', async () => {
+      it('returns data for all valid queries', async () => {
         const validQueryResult = await client.query({
           query: gql`query validButNotWhitelisted {
               cardano {

src/config.ts

@@ -2,7 +2,7 @@ import { IntrospectionNotPermitted, MissingConfig, TracingRequired } from './lib
 import { CorsOptions } from 'apollo-server-express'
 
 export type Config = {
-  allowIntrospection: boolean
+  allowIntrospection?: boolean
   allowedOrigins: CorsOptions['origin']
   apiPort: number
   cacheEnabled: boolean
@@ -35,9 +35,8 @@ export function getConfig (): Config {
   if (whitelistPath && allowIntrospection) {
     throw new IntrospectionNotPermitted('whitelist')
   }
-
   return {
-    allowIntrospection: allowIntrospection || false,
+    allowIntrospection,
     allowedOrigins: allowedOrigins || true,
     apiPort: apiPort || 3100,
     cacheEnabled: cacheEnabled || false,
@@ -62,14 +61,14 @@ function filterAndTypecastEnvs (env: any) {
     WHITELIST_PATH
   } = env
   return {
-    allowIntrospection: ALLOW_INTROSPECTION === 'true',
+    allowIntrospection: ALLOW_INTROSPECTION === 'true' ? true : undefined,
     allowedOrigins: ALLOWED_ORIGINS,
     apiPort: Number(API_PORT),
-    cacheEnabled: CACHE_ENABLED === 'true',
+    cacheEnabled: CACHE_ENABLED === 'true' ? true : undefined,
     hasuraUri: HASURA_URI,
-    prometheusMetrics: PROMETHEUS_METRICS === 'true',
+    prometheusMetrics: PROMETHEUS_METRICS === 'true' ? true : undefined,
     queryDepthLimit: Number(QUERY_DEPTH_LIMIT),
-    tracing: TRACING === 'true',
+    tracing: TRACING === 'true' ? true : undefined,
     whitelistPath: WHITELIST_PATH
   }
 }

src/index.ts

@@ -30,6 +30,7 @@ buildContext(config.hasuraUri)
       cacheControl: config.cacheEnabled ? { defaultMaxAge: 20 } : undefined,
       context,
       introspection: config.allowIntrospection,
+      playground: config.allowIntrospection,
       plugins,
       resolvers,
       validationRules,
@@ -42,6 +43,9 @@ buildContext(config.hasuraUri)
       app.listen({ port: config.apiPort }, () => {
         const serverUri = `http://localhost:${config.apiPort}`
         console.log(`GraphQL HTTP server at ${serverUri}${server.graphqlPath}`)
+        if (process.env.NODE_ENV !== 'production' && config.whitelistPath) {
+          console.warn('As a whitelist is in effect, the GraphQL Playground is available, but will not allow schema exploration')
+        }
         if (config.prometheusMetrics) {
           console.log(`Prometheus metrics at ${serverUri}/metrics`)
         }