Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/**
* Implements the DevTools "Local Mode" backend, which redirects requests
* to local files defined by the Web Developer.
*/
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
FileUtils: "resource://gre/modules/FileUtils.sys.mjs",
NetworkOverride:
"resource://devtools/shared/network-observer/NetworkOverride.sys.mjs",
});
export const NetworkLocalMode = {
/**
* Intercept a early channel that hasn't established a remote connection yet,
* which matches a "Local Mode" origin and should be served from a local file
* located in the folder passed as argument.
*
* @param {nsIHttpChannel} channel
* @param {string} localFolderPath
*/
interceptChannelWithPath(channel, localFolderPath) {
const path = decodeURI(channel.URI.filePath.replace(/^\//, ""));
// On Windows, replace all URI's '/' path separators with '\'
let systemPath = path;
if (Services.appinfo.OS === "WINNT") {
systemPath = systemPath.replace(/\//g, "\\");
}
const overridePath = PathUtils.joinRelative(localFolderPath, systemPath);
let file = new lazy.FileUtils.File(overridePath);
if (!file.exists()) {
// Create a 404 response to avoid leaving any request matching the host
// to fallback to any potential existing http server.
overrideChannelInto404(channel);
return;
}
if (file.isFile()) {
// This is the typical codepath redirecting to a existing local file
lazy.NetworkOverride.overrideChannelWithFilePath(channel, file.path);
return;
}
if (file.isDirectory()) {
// Before showing a directory listing, try to match a valid index HTML file
file.append("index.html");
if (file.exists() && file.isFile()) {
// This is the typical codepath redirecting to a existing local file
lazy.NetworkOverride.overrideChannelWithFilePath(channel, file.path);
return;
}
file = file.parent;
file.append("index.htm");
if (file.exists() && file.isFile()) {
// This is the typical codepath redirecting to a existing local file
lazy.NetworkOverride.overrideChannelWithFilePath(channel, file.path);
return;
}
file = file.parent;
// When we are trying to load a directory, return a file listing instead of 404
// as that's really handy and behaves like a typical development http server.
overrideChannelWithDirectoryListing(channel, path, file);
return;
}
// In case it is neither a file, nor a directory?
overrideChannelInto404(channel);
},
};
/**
* Make it so that an in-flight channel that just started
* is converted into a 404 response for when there is no matching local file
* for that request.
*
* @param {nsIHttpChannel} channel
*/
function overrideChannelInto404(channel) {
const replacedHttpResponse = Cc[
"@mozilla.org/network/replaced-http-response;1"
].createInstance(Ci.nsIReplacedHttpResponse);
replacedHttpResponse.responseStatus = 404;
replacedHttpResponse.responseStatusText = "404 Not Found";
const body = `<h1>DevTools Local Mode</h1><p>No local file for: ${channel.URI.filePath}</p>`;
replacedHttpResponse.responseBody = body;
channel
.QueryInterface(Ci.nsIHttpChannelInternal)
.setResponseOverride(replacedHttpResponse);
}
/**
* Replace the content of an in-flight channel that just started
* that matches a local mode folder into an HTML page listing of
* the available files in that folder.
*
* @param {nsIHttpChannel} channel
* @param {string} folderPath
* @param {nsILocalFile} file
*/
async function overrideChannelWithDirectoryListing(channel, folderPath, file) {
const replacedHttpResponse = Cc[
"@mozilla.org/network/replaced-http-response;1"
].createInstance(Ci.nsIReplacedHttpResponse);
replacedHttpResponse.responseStatus = 200;
replacedHttpResponse.responseStatusText = "OK";
replacedHttpResponse.setResponseHeader("Content-Type", "text/html", false);
// `setResponseOverride` has to be called synchronously after before-connect event
// to really intercept the request.
// Workaround this by suspending the request until we asynchronously retrieve
// the directory listing content
channel.suspend();
// Compute a simple, but meaningful HTML file for the listing
const links = [];
const children = await IOUtils.getChildren(file.path);
for (const childPath of children.sort()) {
const filename = PathUtils.filename(childPath);
const absolutePath =
"/" +
folderPath +
(!folderPath || folderPath.endsWith("/") ? "" : "/") +
filename;
links.push(`<li><a href="${absolutePath}">${filename}</a></li>`);
}
const body =
"<h2>" +
PathUtils.filename(file.path) +
":</h2><ul>" +
links.join("") +
"</ul>";
replacedHttpResponse.responseBody = body;
channel
.QueryInterface(Ci.nsIHttpChannelInternal)
.setResponseOverride(replacedHttpResponse);
channel.resume();
}