💼 express-briefcase

Include metadata in Express.js response json such as errors, warnings and pagination

Installation

npm install express-briefcase

Using the middleware

Using default behavior:

const express = require('express');
const app = express();
app.use(briefcase());

Adding custom metadata:

const express = require('express');
const uuid = require('uuid');
const app = express();
app.use(
  briefcase(shell => {
    shell.requestReferenceId = uuid.v4();
    if (shell.statusClass === '5xx') {
      shell.apology = 'Sorry about that!';
    }
    return shell;
  })
);

Accessing the res object:

const express = require('express');
const uuid = require('uuid');
const app = express();
app.use(
  briefcase(function (shell) {
    // Inside your customizer function, "this" is express's "res" object
    // Note that we must use the "function" keyword, not an arrow function
    shell.statusMessage = this.statusMessage;
    return shell;
  })
);

Using the new res methods

1. res.decoratedJson()
2. res.error()
3. res.devError()
4. res.warn()
5. res.new()
6. res.total()

Using res.decoratedJson()

app.get('/user/:id', async (req, res) => {
  const user = await getUser(req.params.id);
  res.decoratedJson(user);
});

Resulting response JSON

{
  "date": "2022-01-03T04:48:00.095Z",
  "took": 451,
  "status": 200,
  "statusClass": "2xx",
  "success": true,
  "errors": [],
  "warnings": [],
  "new": null,
  "pagination": null,
  "payload": {
    "id": 123,
    "fname": "Joe",
    "lname": "User"
  }
}

---

Using res.error()

app.get('/user/:id', async (req, res) => {
  const user = await getUser(req.params.id);
  if (user === null) {
    // Note: error can be a string or instance of Error
    res.error('User not found');
    res.status(404);
  }
  res.decoratedJson(user);
});

Resulting response JSON

{
  "date": "2022-01-03T04:48:00.095Z",
  "took": 452,
  "status": 404,
  "statusClass": "4xx",
  "success": false,
  "errors": ["User not found"],
  "warnings": [],
  "new": null,
  "pagination": null,
  "payload": null
}

---

Using res.devError()

Same as res.error() except that the error string will only be added if process.env.NODE_ENV === 'development'.

---

Using res.warn()

app.get('/user/:id', async (req, res) => {
  if (req.query.role) {
    res.warn('Passing role to /user/:id is deprecated.');
  }
  const user = await getUser(req.params.id);
  res.decoratedJson(user);
});

Resulting response JSON

{
  "date": "2022-01-03T04:48:00.095Z",
  "took": 458,
  "status": 200,
  "statusClass": "4xx",
  "success": true,
  "errors": [],
  "warnings": ["Passing role to /user/:id is deprecated."],
  "new": null,
  "pagination": null,
  "payload": {
    "id": 123,
    "fname": "Joe",
    "lname": "User"
  }
}

---

Using res.new()

app.post('/user', async (req, res) => {
  const { newId } = await createUser(req.body);
  res.new({ id: newId, url: `/users/${newId}` });
  res.decoratedJson();
});

Resulting response JSON

{
  "date": "2022-01-03T04:48:00.095Z",
  "took": 458,
  "status": 201,
  "statusClass": "2xx",
  "success": true,
  "errors": [],
  "warnings": [],
  "new": {
    "id": 123,
    "url": "/users/123"
  },
  "pagination": null,
  "payload": null
}

---

Using res.total()

app.get('/users/search', async (req, res) => {
  const { list, total } = await getUsers({
    name: req.query.name,
    page: req.query.page,
    limit: 25,
  });
  res.total({ total, page: req.query.page, perPage: 25 });
  res.decoratedJson(user);
});

Resulting response JSON

{
  "date": "2022-01-03T04:48:00.095Z",
  "took": 454,
  "status": 200,
  "statusClass": "2xx",
  "success": true,
  "errors": [],
  "warnings": [],
  "new": null,
  "pagination": {
    "perPage": 25,
    "page": 2,
    "total": 104,
    "numPages": 5,
    "hasNextPage": true,
    "prev": "/users/search?name=John&page=1",
    "next": "/users/search?name=John&page=3"
  },
  "payload": [
    {
      "id": 576,
      "fname": "Jennifer",
      "lname": "Johnson"
    },
    "..."
  ]
}

Unit Tests and Code Coverage

Powered by jest

npm test
npm run coverage

Contributing

Contributions are welcome. Please open a GitHub ticket for bugs or feature requests. Please make a pull request for any fixes or new code you'd like to be incorporated.

License

Open Source under the ISC License.