Make it easier to add new options.

command_line.js

@@ -2,54 +2,59 @@
 
 const fs = require("fs");
 const path = require("path");
-const log = require("loglevel");
 
+const log = require("loglevel");
 const parseArgs = require("minimist");
 
-const opts = {
-    string: ["blacklist", "cert", "copyToDir", "drop", "early", "fileExt", "key", "loglevel", "map", "mode", "port", "proxy", "public"],
-    boolean: ["compress", "headfull", "help", "noserver"]
-  };
-
 const DEFAULT = {
 	PORT: 8080,
 	LOGLEVEL: log.levels.INFO
 };
 
+const options = [
+	{ name: "blacklist", param: "item", desc: `Regex describing files which should not be included in the rendering.` },
+	{ name: "cert", param: "cert", desc: `SSL Certificate to use.` },
+	{ name: "key", param: "key", desc: `SSL Key to use.` },
+	{ name: "drop", param: "toUid:toGid", desc: `The uid and gid that the process should become as soon as possible.` },
+	{ name: "early", param: "urlToEarlyRender", desc: `A URL that should be rendered before listening for requests. Specify multiple times for many URLs.` },
+	{ name: "loglevel", param: "0-5", desc: `Set log levels (according to the loglevel package) to this number. Default is ${DEFAULT.LOGLEVEL}.` },
+	{ name: "map", param: "hostMapping", desc: `Array of JSON objects with from and to properties.` },
+	{ name: "port", param: "thisServerListenPort", desc: `What port should this server listen to for requests. Default is ${DEFAULT.PORT}.` },
+	{ name: "proxy", param: "behindThisProxy", desc: `Indicate that this server is behind this particular proxy.` },
+	{ name: "public", param: "staticFileDirectory", desc: `Serve static files from this directory.` },
+	{ name: "copyToDir", param: "directoryToPutRenderedFile", desc: `Generate a file for each page that is rendered.` },
+	{ name: "fileExt", param: "extension", desc: `Add extension to all files that are generated. For instance, it might be useful to add ".html".` },
+	{ name: "mode", param: "fileMode", desc: `Sets the file mode to be set when files are written.` },
+
+	{ name: "compress", desc: `Allows on the fly compression of reponses.` },
+	{ name: "headfull", desc: `Show the normally headless chrome. Useful for debugging.` },
+	{ name: "help", desc: `Show the usage description.` },
+	{ name: "noserver", desc: `Don't start a server to listen for incoming requests. In other words, just run with files.` },
+];
+
+const opts = {
+	string: options.filter((option) => option.param).map((option) => option.name).sort(),
+	boolean: options.filter((option) => !option.param).map((option) => option.name).sort(),
+}
+
 // Process command line arguments
 const cmdline = process.argv.slice(2);
 const parsed = parseArgs(cmdline, opts);
 
 if(parsed.help) {
-	console.log(`${process.execPath} --map "mapping key:value" [optional options]
-	string/string array options can be repeated any number of times (see minimist package):
-		[--blacklist item] Regex describing files which should not be included in the rendering.
-		[--cert cert] SSL Certificate.
-		[--key key] SSL Key.
-		[--drop toUid:toGid] The uid and gid that the process should become as soon as possible. 
-		[--early urlToEarlyRender] A list of URLs that should be rendered before listening for requests.
-		[--loglevel 0-5] Set log levels according to the loglevel package. Default is ${DEFAULT.LOGLEVEL}
-		[--map hostMapping] Array of JSON objects with from and to properties.
-		[--port thisServerListenPort] What port should this server listen to for requests. Default is ${DEFAULT.PORT}.
-		[--proxy behindThisProxy] Indicate that this server is behind this particular proxy.
-		[--public staticFileDirectory] Serve static files from this directory.
-		[--copyToDir directoryToPutRenderedFile] Generate a file for each page that is rendered.
-		[--fileExt extension] Add extension to all files that are generated. For instance, it might be useful to add ".html".
-		[--mode fileMode] Sets the file mode to be set when files are written.
-
-	boolean options need only be provided once with no additional tokens:
-		[--compress] Allows on the fly compression of reponses
-		[--headfull] Show the normally headless chrome. Useful for debugging.
-		[--help] Show this help
-		[--noserver] Indicate that we don't need the server started. In other words, just run with files.`);
+	console.log(`${process.execPath} --map "mapping key:value" [optional options]\n`,
+		`Supported string options which can be repeated any number of times (see minimist package):\n`,
+		`${options.filter((option) => option.param).reduce((accum, option) => accum + `\t[--${option.name} ${option.param}] ${option.desc}\n`, "")}\n`,
+		`Supported boolean options are:`,
+		`${options.filter((option) => option.param).reduce((accum, option) => accum + `\n\t[--${option.name}] ${option.desc}`, "")}`);
 
 	// Indicate that we'd like the program to exit when it can.
 	process.exit(0);
 }
 
 // Must have --map provided
 console.assert(parsed._.length === 0, "Unhandled arguments!", parsed._);
-console.assert(parsed.map, "No mapping provided", parsed.map);
+console.assert(parsed.map, "No mapping provided");
 
 // If noserver is provided, ensure that copyToDir is provided.
 console.assert(parsed.noserver ? parsed.copyToDir && parsed.early : true, "--noserver should have --copyToDir and --early provided", parsed.noserver, parsed.copyToDir, parsed.early);