# repl-ns

> Namespace for REPL driven development

Latest version **0.0.25** (published 2023-08-24) · MIT license · 0 weekly downloads

## Install

```sh
npm install repl-ns
pnpm add repl-ns
yarn add repl-ns
bun add repl-ns
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: has types; no vulnerabilities; high quality score.

Warnings: low downloads; no esm support; pre 1.0.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.0.25 |
| Published | 2023-08-24 |
| First published | 2022-12-03 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 6.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 4 |
| Author | Vladislav Botvin |
| Maintainers | darrrk |
| Keywords | repl, clojure, ts, typescript, driven, development |

## Links

- npm: https://www.npmjs.com/package/repl-ns
- Repository: https://github.com/darky/repl-ns
- Homepage: https://github.com/darky/repl-ns#readme
- Issues: https://github.com/darky/repl-ns/issues
- npm.io page: https://npm.io/package/repl-ns

## Alternatives

- [csv-to-markdown-table](https://npm.io/package/csv-to-markdown-table.md) — 47.0K weekly downloads
- [@sapphire/ratelimits](https://npm.io/package/@sapphire/ratelimits.md) — 4.4K weekly downloads
- [js-csvparser](https://npm.io/package/js-csvparser.md) — 2.0K weekly downloads
- [@adadapted/js-sdk](https://npm.io/package/@adadapted/js-sdk.md) — 251 weekly downloads
- [@grapecity/spread-sheets-sparklines](https://npm.io/package/@grapecity/spread-sheets-sparklines.md) — 103 weekly downloads

## Recent versions

- 0.0.25 (latest) — 2023-08-24
- 0.0.15 — 2022-12-03

## README

# repl-ns

Namespace for REPL driven development for TypeScript/JavaScript. 
Inspired by Clojure namespaces.
Currently tested on Node.js, but potentially can be used on any JavaScript runtime (Deno, Bun, Browser and so on...)

### Why REPL driven development?

*TL;DR Because it fastest, glad and fun way to develop software. Clojure guys approve it*

Node.js development process evolved gradually. At the beginning was nothing, and developers restarted node.js from scratch manually for code testing.
Then some automation appears [nodemon](https://nodemon.io/). Fine! Now I can relax from boring `Ctrl+C` -> `UP` -> `Enter` process. But it's not enough! Restarting node.js process from scratch is very expensive! 
* Need to require in runtime all project files. Yes! All this hundreds files of your 3+ years old monolith 😊
* Seems you have TypeScript too. Need to transpile all this kind with additional time wasting (Yeah! Say hello to ts-node perf tweak and all new TypeScript compilers, which written on Rust/C++/Go 😀)
* And establish DB connection too
* And establish Kafka/RabbitMQ/SQS connection too
* And establish Redis connection too
* And start HTTP server too

☝️ And all this seconds wasting process for just testing one line of code, that I change?<br/>
Maybe better "restart" one function instead whole process, where this line of code was changed?

### How to use (example)

Run your node.js program with `--inpsect` flag. Exposed inspect protocol will be used for REPL driven development.

Then organize code in your project using REPL driven development friendly style:

*some-namespace.ts*

```ts
import { ns } from 'repl-ns';

export const someNS = ns('some-namespace', {
  fn() {
    return 1 + 1
  },
});
```

And call namespace related functions anywhere:

```ts
import { someNS } from 'src/some-namespace';

someNS().fn() // 2
```

Now you can replace `someNS.fn` implementation in runtime without restarting node.js process. <br/>
Just edit *some-namespace.ts*

```ts
- return 1 + 1
+ return 2 + 2
```

and use, for example, [node-remote-repl](https://github.com/darky/node-remote-repl) - `node-remote-repl some-namespace.ts`<br/>
Now anywhere `someNS().fn() // will return 4`<br/>
BTW, setup IDE for REPL driven development [VSCode example](https://github.com/darky/node-remote-repl#integration-with-ide)

Awesome! 🦄 Now fastest REPL driven development with node.js at your fingertips 

### Detailed example

```ts
import { ns } from 'repl-ns';

export const someNS = ns('some-namespace', {
  fn() {
    return 1 + 1 // functions always will be replaced in REPL
  },
  
  obj: {foo: 'bar'} // objects will be preserved in REPL by default (for stateful)
}, {
  forceRewrite: true, // if you want force replace objects too, this option will be helpful
  rewriteKeys: ['obj'], // or you can pick specific items for replacing
  async before(props) {
    // optional before hook namespace initialization
    // old namespace payload will be passed in props (if exists)
    // here you can close DB connection, stop HTTP server and so on
  },
  async after(props) {
    // optional after hook namespace initialization
    // new namespace payload will be passed in props
    // here you can establish DB connection, start HTTP server and so on
  },
  sync: true // pass sync: true if your namespace has totally sync behaviour
});

await someNS.ready // promise for ready state of namespace (before, after hooks executed yet)
```

### Real projects used repl-ns

You can explain code of projects:

* [ytdl-tui](https://github.com/darky/ytdl-tui) - TUI for downloading YouTube videos, totally writen with REPL driven development approach using **repl-ns**

### Caveats

Avoid using relative paths in your project:

```ts
import { someNS } from '../../some-namespace';
```

Because REPL code is run in root and can't detect relative paths

Use non-relative paths instead:

```ts
import { someNS } from 'src/some-namespace';
```

Projects, which helps with non-relative paths:
* [tsconfig-paths](https://github.com/dividab/tsconfig-paths)
* [tsc-alias](https://github.com/justkey007/tsc-alias)

---
_Source: https://npm.io/package/repl-ns · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._