Extract and modernize the webserver's directory listing code

The `handler` method contained this code in an inline function, which
made the `handler` method big and harder to read. Moreover, this code
relied on variables from the outer scope, which made it harder to reason
about because the inputs and outputs weren't easily visible.

This commit fixes the problems by extracting the directory listing code
into a dedicated private method, and modernizing it to use e.g. `const`/
`let` instead of `var` and using template strings.
This commit is contained in:
Tim van der Meij 2024-02-11 16:46:01 +01:00
parent 336fcffd28
commit ce4fe0c234
No known key found for this signature in database
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@ -16,6 +16,7 @@
/* eslint-disable no-var */
import fs from "fs";
import fsPromises from "fs/promises";
import http from "http";
import path from "path";
@ -162,7 +163,7 @@ class WebServer {
return;
}
if (isDir) {
serveDirectoryIndex(filePath);
self.#serveDirectoryIndex(res, pathPart, queryPart, filePath);
return;
}
@ -196,97 +197,101 @@ class WebServer {
}
self.#serveFile(res, filePath, fileSize);
}
}
function escapeHTML(untrusted) {
async #serveDirectoryIndex(response, pathPart, queryPart, directory) {
response.setHeader("Content-Type", "text/html");
response.writeHead(200);
if (queryPart === "frame") {
response.end(
`<html>
<frameset cols=*,200>
<frame name=pdf>
<frame src="${encodeURI(pathPart)}?side">
</frameset>
</html>`,
"utf8"
);
return;
}
let files;
try {
files = await fsPromises.readdir(directory);
} catch {
response.end();
return;
}
response.write(
`<html>
<head>
<meta charset="utf-8">
</head>
<body>
<h1>Index of ${pathPart}</h1>`
);
if (pathPart !== "/") {
response.write('<a href="..">..</a><br>');
}
const all = queryPart === "all";
const escapeHTML = untrusted =>
// Escape untrusted input so that it can safely be used in a HTML response
// in HTML and in HTML attributes.
return untrusted
untrusted
.replaceAll("&", "&amp;")
.replaceAll("<", "&lt;")
.replaceAll(">", "&gt;")
.replaceAll('"', "&quot;")
.replaceAll("'", "&#39;");
}
function serveDirectoryIndex(dir) {
res.setHeader("Content-Type", "text/html");
res.writeHead(200);
for (const file of files) {
let stat;
const item = pathPart + file;
let href = "";
let label = "";
let extraAttributes = "";
if (queryPart === "frame") {
res.end(
"<html><frameset cols=*,200><frame name=pdf>" +
'<frame src="' +
encodeURI(pathPart) +
'?side"></frameset></html>',
"utf8"
);
return;
try {
stat = fs.statSync(path.join(directory, file));
} catch (ex) {
href = encodeURI(item);
label = `${file} (${ex})`;
extraAttributes = ' style="color:red"';
}
var all = queryPart === "all";
fs.readdir(dir, function (err, files) {
if (err) {
res.end();
return;
if (stat) {
if (stat.isDirectory()) {
href = encodeURI(item);
label = file;
} else if (path.extname(file).toLowerCase() === ".pdf") {
href = `/web/viewer.html?file=${encodeURIComponent(item)}`;
label = file;
extraAttributes = ' target="pdf"';
} else if (all) {
href = encodeURI(item);
label = file;
}
res.write(
'<html><head><meta charset="utf-8"></head><body>' +
"<h1>PDFs of " +
pathPart +
"</h1>\n"
}
if (label) {
response.write(
`<a href="${escapeHTML(href)}"${extraAttributes}>${escapeHTML(label)}</a><br>`
);
if (pathPart !== "/") {
res.write('<a href="..">..</a><br>\n');
}
files.forEach(function (file) {
var stat;
var item = pathPart + file;
var href = "";
var label = "";
var extraAttributes = "";
try {
stat = fs.statSync(path.join(dir, file));
} catch (e) {
href = encodeURI(item);
label = file + " (" + e + ")";
extraAttributes = ' style="color:red"';
}
if (stat) {
if (stat.isDirectory()) {
href = encodeURI(item);
label = file;
} else if (path.extname(file).toLowerCase() === ".pdf") {
href = "/web/viewer.html?file=" + encodeURIComponent(item);
label = file;
extraAttributes = ' target="pdf"';
} else if (all) {
href = encodeURI(item);
label = file;
}
}
if (label) {
res.write(
'<a href="' +
escapeHTML(href) +
'"' +
extraAttributes +
">" +
escapeHTML(label) +
"</a><br>\n"
);
}
});
if (files.length === 0) {
res.write("<p>no files found</p>\n");
}
if (!all && queryPart !== "side") {
res.write(
"<hr><p>(only PDF files are shown, " +
'<a href="?all">show all</a>)</p>\n'
);
}
res.end("</body></html>");
});
}
}
if (files.length === 0) {
response.write("<p>No files found</p>");
}
if (!all && queryPart !== "side") {
response.write(
'<hr><p>(only PDF files are shown, <a href="?all">show all</a>)</p>'
);
}
response.end("</body></html>");
}
#serveFile(response, filePath, fileSize) {