Ts-logs NPM | npm.io

ts-logs

Understand what happens in your application. Manage your logs and audit the steps of each request.

About the lib

This package provide a sdk to manage logs.

Installation

install using yarn or npm

$ npm install ts-logs

# OR

$ yarn add ts-logs

Documentation

Example

import { Log, Step } from 'ts-logs';

// create a global log
const log = Log.init({ name: 'First Log', origin: 'https://global.com' });

// create steps
const info = Step.info({ message: 'Fetching api...', name: 'Request Login', method: 'POST' });
const error = Step.error({ message: 'Timeout', name: 'Login', stack: 'Error stack' });

// add steps to global log
log.addSteps([ info, error ]);

// print or save logs
log.print();
await log.writeLocal();
await log.publish(config);

Use a Singleton Instance Globally

You can use a global log to publish once on finish all process

import { GlobalLog, Config } from 'ts-logs';

const global = GlobalLog.singleton();

// ...

global.addStep(step);

// ...

await global.publish(Config.Mongo({ url: 'mongodb://localhost:27017' }));

// remember when using global log as singleton clear steps
global.clear();

Create step from catch block

Create a step instance from error. This method get many important information from axios error.

class DoSomething {
    async execute(data: Data): Promise<void> {
        try {
            
            // try do something ...
            await axios.post(url, data);

        } catch(error) {

            // create step instance from error
            global.addStep(Step.catch(error));
        }
    }
}

Log object

Example generated log. The log is a json object with array of step object

{
  "uid": "1c7e5aca-c9f4-4e33-a5e7-d8a9cfe94053",
  "name": "Log Example",
  "ip": "127.0.0.1",
  "origin": "http://127.0.0.1:3000",
  "createdAt": "2023-02-05T23:00:40.481Z",
  "stateType": "stateful",
  "steps": [
    {
      "name": "Find Item",
      "category": "none",
      "tags": ["item", "product", "card"],
      "url": "https://my-app.com/products/1",
      "stack": "none",
      "data": "none",
      "statusCode": 200,
      "message": "Fetching api...",
      "type": "info",
      "method": "GET",
      "createdAt": "2023-02-05T23:00:40.481Z",
      "uid": "673e17fb-55aa-4ea9-8668-e34b94bfd22c",
      "additionalInfo": "a complementary information"
    }
  ]
}

Use as middleware

Express middleware to capture app errors.

import express from 'express';
import { stackLog } from 'ts-logs';

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

// ...
app.use(routes);

// last middleware to handle errors using `stackLog` all errors will be intercepted.
app.use(stackLog({ writeLocal: true })); // <------ middleware

app.liste(3000);

Bind

You also may use bind middleware to apply a log instance to request

import express from 'express';
import { bindLog, Config } from 'ts-logs';

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

// on top of routes you can bind a log instance to request
app.use(bindLog()); // <------ middleware

app.get("/log", async (req: Request, res: Response) => {

    // you can do anything with log instance from request.
    req.log.addStep( /* any step */ );
    req.log.print(); // show steps on terminal
    await req.log.publish(Config.S3(/* ... */)) // publish to s3

    res.status(200).json(req.log);
});

// ...

app.use(routes);

Use as middleware step

if you use many steps as middleware you can use global log

import express from 'express';
import { bindLog, Config } from 'ts-logs';

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

// on top of routes you can bind a log instance to request
app.use(bindLog()); // <------ middleware

app.get("/process", (req: Request, res: Response, next: NextFunction) => {

    // you can do anything with log instance
    req.log.addStep( /* info step */ ); // <------ add step to global log state.

    // call next step
    next();
}, (req: Request, res: Response, next: NextFunction) => {

    // you can do anything with log instance
    req.log.addStep( /* error step */ ); // <------ add step to global log state.

    // call next step
    next();
}, async (req: Request, res: Response, next: NextFunction) => {

    // you can do anything with log instance
    req.log.addStep( /* stack step */ ); // <------ add step to global log state.

    // publish log with steps to aws s3
    await req.log.publish(Config.S3(/* ... */));

    // send log to client
    res.status(200).json(req.log);
});

// ...

app.use(routes);

Publish log automatically

you can use in conjunction with binding middleware other middleware to automatically publish logs to your preferred provider.

import express from 'express';
import { bindLog, autoPublishLog, Config } from 'ts-logs';

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

// on top of routes you can bind a log instance to request
app.use(bindLog()); // <------ middleware

// after `bindLog` add `autoPublishLog` to automatically publish logs
app.use(autoPublishLog(Config.S3())); // <------ middleware

app.get("/log", async (req: Request, res: Response) => {

    // you can do anything with log instance from request.
    req.log.addStep( /* any step */ ); // <------ add step to publish

    res.status(200).json(req.log);
});

// ...

app.use(routes);

Secure logs

It is possible to remove any key from body (data) or encrypt some sensitive information

Removing data

const name = "Step Test";
const data = JSON.stringify({ password: "123456", name: "Jane" });

const step = Step.create({ name, data });

const updated = step.remove(["password"]);

console.log(updated.data);

> "{ \"name\": \"Jane\" }"

// or encrypt attribute

step.encrypt({ attributes: ["password"], secretKey: "my-secret-key" });

Hidden Value - Mask

you can mask any key value in step data. provide the key name you want or the path. example user.password for specific key in user object or password for any key called password

const name = 'sample';

const data = { 
  info: 'secret-text', 
  user: { 
    name: 'Jane',
    password: '12345'
  }
};

const step = Step.create({ name, data });

const updated = step.mask([ { key: 'password' } ]);

console.log(updated);
{
  info: 'secret-text', 
  user: { 
    name: 'Jane',
    password: '*****'
  } 
}

Encrypt data

Encryption is also available for stackLog and as cypher.

app.use(
  stackLog({ 
    writeLocal: true, 
    encrypt: true, 
    encryptOption: { 
      level: "cypher",
      secretKey: "my-secret-key"
    } 
  })
);