UnhandledPromiseRejectionWarning: Error: You must await server.start() before calling server.applyMiddleware() at ApolloServer

To solve UnhandledPromiseRejectionWarning: Error: You must await server.start() before calling server.applyMiddleware() at ApolloServer error follow below methods.

ERROR LOG

UnhandledPromiseRejectionWarning: Error: You must await server.start() before calling server.applyMiddleware() at ApolloServer

How to solve UnhandledPromiseRejectionWarning: Error: You must await server.start() before calling server.applyMiddleware() at ApolloServer ?

To solve the UnhandledPromiseRejectionWarning: Error: You must await server.start() before calling server.applyMiddleware() at ApolloServer error simply downgrade the the apollo server to apollo-server-express@^2

Alternative to Solve UnhandledPromiseRejectionWarning: Error: You must await server.start() before calling server.applyMiddleware() at ApolloServer

When I upgraded Ben Awad’s Graphql-Next-Typeorm[…] stack, I encountered this problem; simply adding an await to server start fixed the warnings. Refer the code below.

const apolloServer = new ApolloServer({
    introspection: true,
    schema: await buildSchema({
      resolvers: [__dirname + '/resolvers/**/*.js'],
      validate: false
    }),
    context: ({ req, res }) => ({
      req,
      res,
      redis: redisClient
    }),
    formatError
  });


// added this line
  await apolloServer.start();

  apolloServer.applyMiddleware({
    app,
    cors: false
  });

Hope the above solution works.

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