fsp.NiceError

An extension for TS/JS Error Object, brings you better development experience.

Features:

• traceable, intuitional error chain
• support extra infomation
• zero dependency
• support both nodejs and deno runtime

Import to your project

For Node.js

Install it first:

 # pay attention to the package name 'fsp-nice-error'
npm install fsp-nice-error
 # or
yarn add fsp-nice-error

Then import it:

// CommonJS
const { NiceError } = require('fsp-nice-error')
// ES Module or TypeScript, need bundlers(rollup/webpack/parcel...) support for current nodejs version
import { NiceError } from 'fsp-nice-error'
// TypeScript
import { NiceError } from 'fsp-nice-error/mod'

For Deno

Option 1

Just copy src/NiceError.ts file to your project, and then import it:

import { NiceError } from "path/to/NiceError.ts"

Option 2

Directly import it from remote sources:

// from denopkg
import { NiceError } from "https://denopkg.com/FullStackPlayer/fsp.NiceError@master/mod.ts"
// from deno.land
import { NiceError } from "https://deno.land/x/fsp_nice_error/mod.ts"

Usage

For better experience

Set static property execPath for NiceError will shorten the trace stack info.

// nodejs
NiceError.execPath = process.cwd()
// deno
NiceError.execPath = Deno.cwd()

Handling inner error

// a normal js Error
const err = new Error('This is a normal error')

// a NiceError which takes err as it's inner error
const ne1 = new NiceError('A normal error was caught!',{
    name: 'NiceError',
    cause: err,
    info: {
        foo: 'foo'
    }
})

// another NiceError which takes ne1 as it's inner error
const ne2 = new NiceError('An inner NiceError was caught!',{
    name: 'AppError',
    cause: ne1,
    info: {
        bar: 'bar'
    }
})

console.log(ne2.message)
/**
output:
------------------------------
An inner NiceError was caught!
------------------------------
*/

console.log(ne2.fullMessage())
/**
output:
------------------------------
[AppError]: An inner NiceError was caught! <= [NiceError]: A normal error was caught! <= [Error]: This is a normal error
------------------------------
*/

console.log(ne2.fullStack())
/**
output:
------------------------------
[AppError]: An inner NiceError was caught! <= [NiceError]: A normal error was caught! <= [Error]: This is a normal error
    at Object.<anonymous> (./sample/nodeEnv.js:16:11)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
    at internal/main/run_main_module.js:17:47
Caused by [NiceError]: A normal error was caught! <= [Error]: This is a normal error
    at Object.<anonymous> (./sample/nodeEnv.js:7:11)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
    at internal/main/run_main_module.js:17:47
Caused by [Error]: This is a normal error
    at Object.<anonymous> (./sample/nodeEnv.js:4:11)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
    at internal/main/run_main_module.js:17:47
*/

console.log(ne2.fullInfo())
/**
output:
------------------------------
{
    foo: 'foo',
    bar: 'bar'
}
------------------------------
*/

Handling unexpected thown object as inner error

const err = { foo: 'bar'}
try {
    // just throw an object
    throw err
}
catch(err) {
    // a NiceError which takes the thrown object as inner err
    const ne1 = new NiceError('An object was thrown',{
        name: 'NiceError',
        cause: err
    })

    console.log(ne1.fullMessage())
    /**
    output:
    ------------------------------
    [NiceError]: An object was thrown <= [Throw]: type = object, content = {"foo":"bar"}
    ------------------------------
    */

    console.log(ne1.fullStack())
    /**
    output:
    ------------------------------
    [NiceError]: An object was thrown <= [Throw]: type = object, content = {"foo":"bar"}
        at Object.<anonymous> (./sample/nodeEnv.js:39:15)
        at Module._compile (internal/modules/cjs/loader.js:1063:30)
        at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
        at Module.load (internal/modules/cjs/loader.js:928:32)
        at Function.Module._load (internal/modules/cjs/loader.js:769:14)
        at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
        at internal/main/run_main_module.js:17:47
    Caused by [Throw]: type = object, content = {"foo":"bar"}
        at Object.<anonymous> (./sample/nodeEnv.js:46:21)
        at Module._compile (internal/modules/cjs/loader.js:1063:30)
        at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
        at Module.load (internal/modules/cjs/loader.js:928:32)
        at Function.Module._load (internal/modules/cjs/loader.js:769:14)
        at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
        at internal/main/run_main_module.js:17:47
    ------------------------------
    */
}

NiceError with chain property

try {
    throw new NiceError('NiceError With Chain', {
        chain: ['root','folder']
    })
}
catch(ex) {
    console.log(ex.fullMessage())
    /**
    output:
    ------------------------------
    [NiceError@root/folder]: NiceError With Chain
    ------------------------------
    */
}

API

Class NiceError

• Static Property
  • execPath - String - script base path for replacing it from stack info
• Property
  • name - String - error name
  • message - String - error message
  • chain - String[] - error chain array
  • info - Object - context infomation about the error
  • stack - String - stack trace of the error
• Method
  • fullMessage() - String - get all the messages of the error chain path
  • fullStack() - String - get all the stack infomations of the error chain path
  • fullInfo() - Object - merge all the info objects in this error chain into one big info object

Enjoy it :-)