Inject contents into the HTML <body> tag of an HTTP response
const {createServer} = require('http');
const fetch = require('node-fetch');
const injectBody = require('inject-body');
createServer((req, res) => {
injectBody(res, Buffer.from('Hello '));
res.setHeader('content-type', 'text/html');
res.end('<html><body>World</body></html>');
}).listen(3000, async () => {
return (await fetch('http://localhost:3000')).text(); //=> '<html><body>Hello, World</body></html>'
});npm install inject-body
const injectBody = require('inject-body');response: http.ServerResponse
contents: Buffer
If the media type of the response is text/html, it inserts a given contents into the response body as the first child of <body> tag, with increasing the value of Content-Length header if necessary.
const {createServer} = require('http');
const fetch = require('node-fetch');
const injectBody = require('inject-body');
const html = Buffer.from('<html><body><h2>Hi</h2></body></html>');
const inserted = Buffer.from('<h1>🏄</h1>');
createServer((req, res) => {
injectBody(res, inserted);
res.setHeader('content-type', 'text/html');
res.setHeader('content-length', 37/* Buffer.byteLength(html) */);
res.end(html);
}).listen(3000, async () => {
const response = await fetch('http://localhost:3000');
Number(response.headers.get('content-length'));
//=> 53, Buffer.byteLength(html) + Buffer.byteLength(inserted)
return response.text(); //=> '<html><body><h1>🏄</h1><h2>Hi</h2></body></html>'
});If the media type is not text/html or the response body has no <body> tag, it does nothing.
contents: Buffer
Return: Function
Create a new injectBody function with the fixed contents argument. Use this class if a server will inject the same contents into every HTML response many times.
const {InjectBody} = require('inject-body');
const injectStyle = new InjectBody(Buffer.from('<style>body {color: red}</style>'));ISC License © 2018 Shinnosuke Watanabe