devsite/node_modules/@11ty/eleventy-dev-server/server/wrapResponse.js

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JavaScript
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2024-07-08 01:49:38 +00:00
function getContentType(headers) {
if(!headers) {
return;
}
for(let key in headers) {
if(key.toLowerCase() === "content-type") {
return headers[key];
}
}
}
// Inspired by `resp-modifier` https://github.com/shakyShane/resp-modifier/blob/4a000203c9db630bcfc3b6bb8ea2abc090ae0139/index.js
function wrapResponse(resp, transformHtml) {
resp._wrappedOriginalWrite = resp.write;
resp._wrappedOriginalWriteHead = resp.writeHead;
resp._wrappedOriginalEnd = resp.end;
resp._wrappedHeaders = [];
resp._wrappedTransformHtml = transformHtml;
resp._hasEnded = false;
resp._shouldForceEnd = false;
// Compatibility with web standards Response()
Object.defineProperty(resp, "body", {
// Returns write cache
get: function() {
if(typeof this._writeCache === "string") {
return this._writeCache;
}
},
// Usage:
// res.body = ""; // overwrite existing content
// res.body += ""; // append to existing content, can also res.write("") to append
set: function(data) {
if(typeof data === "string") {
this._writeCache = data;
}
}
});
// Compatibility with web standards Response()
Object.defineProperty(resp, "bodyUsed", {
get: function() {
return this._hasEnded;
}
})
// Original signature writeHead(statusCode[, statusMessage][, headers])
resp.writeHead = function(statusCode, ...args) {
let headers = args[args.length - 1];
// statusMessage is a string
if(typeof headers !== "string") {
this._contentType = getContentType(headers);
}
if((this._contentType || "").startsWith("text/html")) {
this._wrappedHeaders.push([statusCode, ...args]);
} else {
return this._wrappedOriginalWriteHead(statusCode, ...args);
}
return this;
}
// data can be a String or Buffer
resp.write = function(data, ...args) {
if(typeof data === "string") {
if(!this._writeCache) {
this._writeCache = "";
}
// TODO encoding and callback args
this._writeCache += data;
} else {
// Buffers
return this._wrappedOriginalWrite(data, ...args);
}
return this;
}
// data can be a String or Buffer
resp.end = function(data, encoding, callback) {
resp._hasEnded = true;
if(typeof this._writeCache === "string" || typeof data === "string") {
// Strings
if(!this._writeCache) {
this._writeCache = "";
}
if(typeof data === "string") {
this._writeCache += data;
}
let result = this._writeCache;
// Only transform HTML
// Note the “setHeader versus writeHead” note on https://nodejs.org/api/http.html#responsewriteheadstatuscode-statusmessage-headers
let contentType = this._contentType || getContentType(this.getHeaders());
if(contentType && contentType.startsWith("text/html")) {
if(this._wrappedTransformHtml && typeof this._wrappedTransformHtml === "function") {
result = this._wrappedTransformHtml(result);
this.setHeader("Content-Length", Buffer.byteLength(result));
}
}
for(let headers of this._wrappedHeaders) {
this._wrappedOriginalWriteHead(...headers);
}
this._writeCache = [];
this._wrappedOriginalWrite(result, encoding)
return this._wrappedOriginalEnd(callback);
} else {
// Buffers
for(let headers of this._wrappedHeaders) {
this._wrappedOriginalWriteHead(...headers);
}
if(data) {
this._wrappedOriginalWrite(data, encoding);
}
return this._wrappedOriginalEnd(callback);
}
}
return resp;
}
module.exports = wrapResponse;