Initial commit

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

@@ -0,0 +1,129 @@
+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;