https://github.com/awwright/node-http-transform
Node.js Transform stream with HTTP support
https://github.com/awwright/node-http-transform
Last synced: 2 months ago
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Node.js Transform stream with HTTP support
- Host: GitHub
- URL: https://github.com/awwright/node-http-transform
- Owner: awwright
- License: unlicense
- Created: 2018-10-06T17:57:11.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2020-07-27T20:52:10.000Z (almost 6 years ago)
- Last Synced: 2025-10-11T05:46:05.794Z (8 months ago)
- Language: JavaScript
- Size: 209 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# http-transform
An extension of the Node.js Transform stream that additionally supports the HTTP header interface.
* `RequestPair`: creates a pair of related streams, one writable, one readable; anything written to the `clientWritableSide` is readable on the `serverReadableSide`.
* `ResponsePair`: creates a pair of related streams, one writable, one readable; anything written to the `serverWritableSide` is readable on the `clientReadableSide`.
* `ResponsePassThrough`: creates a Duplex stream that also stores HTTP headers; anything written to it becomes readable. Headers are passed through as exactly as possible. It should typically possible to pipe a response through a ResponsePassThrough instance with no change in behavior. This is typically used to programmatically create a response that's readable the same way a Node.js `req` object is, and can be piped to a `res` server response object.
## TODO
* `RequestPassThrough` — Request variation of `ResponsePassThrough`
* `RequestThroughOrigin` — subclass of RequestPair that applies header normalizations, as if the request is actually going through the network.
* `ResponseThroughOrigin` — subclass of ResponsePair that applies header normalizations, as if the response is actually going through the network.
## Features
Mock a readable response object:
```javascript
function makeResponse(){
const res = new ResponsePassThrough;
res.setHeader('Content-Type', 'text/plain')
res.write('Line\r\n');
return res.readableClientSide;
}
```
Add a Content-Type to a ReadableStream:
```javascript
const http = require('http');
const { createReadStream } = require('fs');
const { inherits } = require('util');
const { ResponseTransform } = require('.');
const { markdown } = require( "markdown" );
class MarkdownTransform extends ResponseTransform {
constructor() {
super();
const [ input, output ] = this.makeStreams();
output.setHeader('Content-Type', 'application/xhtml+xml');
output.write('');
output.write('');
output.write(' ');
output.write(' ');
output.write(' ');
output.write(' ');
output.write(' ');
output.write(' ');
output.write(' ');
input.once('readable', async function(){
var source = '';
for await(var chunk of input) source += chunk.toString();
output.write(markdown.toHTML(this.sourceContents));
output.write(' ');
output.write(' ');
output.write('');
output.end();
});
}
};
const server = http.createServer(function(req, res) {
if(req.url!=='/'){
res.statusCode = 404;
res.end('404 Not Found\n');
return;
}
if(req.method!=='GET'){
res.statusCode = 501;
res.setHeader('Allow', 'GET');
res.end('501 Not Implemented\n');
return;
}
createReadStream('README.md').pipe(new MarkdownTransform).pipe(res);
});
server.listen(8080);
```
## API
### ResponseTransform
A subclass of the Node.js Transform that also transforms HTTP headers and status code.
Properties/methods:
* headersReady - A promise that resolves when headers have been committed and are ready to be read
### PassThrough
Accepts input and passes it to the write target(s).
This can be used to convert a typical ReadableStream into one that produces HTTP headers.
### Headers
Headers is a simple container for HTTP headers. Its methods and properties are imported into ServerResponseTransform.
Properties/methods, as implemented in Node.js:
* statusCode
* statusMessage
* getHeader(name)
* setHeader(name, value)
* removeHeader(name)
* getHeaderNames()
* getHeaders()
* hasHeader(name)
* pipe(dst)
Additional methods:
* addHeader(name, value)
* pipeHeaders(dst) - copy status/message fields to `dst`
* pipeMessage(dst) - copy status, message fields, and pipe the stream to `dst`