SyntaxError: Unexpected token u in JSON at position 1 curl request

Question

Anyone have a clue why I'm getting this error when running this request on powershell?

curl.exe -d '{"username" : "username"}' -H "Content-Type: application/json" -X POST http://localhost:5200/auth

index.js file:

const dialogflow = require("dialogflow");
const uuid = require("uuid");
const express = require("express");
const StreamChat = require("stream-chat").StreamChat;
const cors = require("cors");
const dotenv = require("dotenv");

const port = process.env.PORT || 5200;

async function runSample(text, projectId = process.env.GOOGLE_PROJECT_ID) {
  const sessionId = uuid.v4();

  const sessionClient = new dialogflow.SessionsClient();
  const sessionPath = sessionClient.sessionPath(projectId, sessionId);

  const request = {
    session: sessionPath,
    queryInput: {
      text: {
        text: text,
        languageCode: "en-US",
      },
    },
  };

  const responses = await sessionClient.detectIntent(request);

  const result = responses[0].queryResult;
  if (result.action === "input.unknown") {
    // If unknown, return the original text
    return text;
  }

  return result.fulfillmentText;
}

dotenv.config();

const app = express();
app.use(express.json());
app.use(cors());

const client = new StreamChat(process.env.API_KEY, process.env.API_SECRET);

const channel = client.channel("messaging", "dialogflow", {
  name: "Dialogflow chat",
  created_by: { id: "admin" },
});

app.post("/dialogflow", async (req, res) => {
  const { text } = req.body;

  if (text === undefined || text.length == 0) {
    res.status(400).send({
      status: false,
      message: "Text is required",
    });
    return;
  }

  runSample(text)
    .then((text) => {
      channel.sendMessage({
        text: text,
        user: {
          id: "admin",
          image: "ignorethis",
          name: "Admin bot",
        },
      });
      res.json({
        status: true,
        text: text,
      });
    })
    .catch((err) => {
      console.log(err);
      res.json({
        status: false,
      });
    });
});

app.post("/auth", async (req, res) => {
  const username = req.body.username;
  
  const token = client.createToken(username);

  await client.updateUser({ id: username, name: username }, token);

  await channel.create();

  await channel.addMembers([username, "admin"]);

  await channel.sendMessage({
    text: "Welcome to this channel. Ask me few questions",
    user: { id: "admin" },
  });

  res.json({
    status: true,
    token,
    username,
  });
});

app.listen(port, () => console.log(`App listening on port ${port}!`));

package.json

{
 "name": "server",
 "version": "1.0.0",
 "main": "index.js",
 "license": "MIT",
 "dependencies": {
   "cors": "^2.8.5",
   "dialogflow": "^4.0.3",
   "dotenv": "^8.2.0",
   "express": "^4.17.1",
   "stream-chat": "^2.9.0",
   "uuid": "^8.3.2"
}

I'd really appreciate if anyone has a clue on what could be causing the issue, cause I'm lost

edit: So I fixed the format as suggested to:

curl.exe -d "{'username' : 'username'}" -H "Content-Type: application/json" -X POST http://localhost:5200/auth

and now I get SyntaxError: Unexpected token ' in JSON at position 1
   at JSON.parse in powershell which translates to:

SyntaxError: Unexpected token ' in JSON at position 1 on the server

Thanks again.

Answer 1

The curl command with the following format works well on Linux platform but it fails on Windows

curl... -d '{"username" : "username"}' ...

From the Windows we have to use the following format:

curl.exe -d "{'username' : 'username'}" -H "Content-Type: application/json" -X POST http://localhost:5200/auth

Basically shell treats the double quotes as a part of the syntax and strips them, so you need to escape them

curl.exe -d "{\"username\":\ \"username\"}" -H "Content-Type: application/json" -X POST http://localhost:5200/auth

See this answer for more information.