From e62b879b488f40acd4e7e95d70c53a91c45810ed Mon Sep 17 00:00:00 2001
From: "Alex Lam S.L" <alexlamsl@gmail.com>
Date: Sun, 28 May 2017 22:57:20 +0800
Subject: [PATCH] display default values in `--help options` (#2018)

---
 README.md    |  5 +++--
 bin/uglifyjs | 11 ++++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 985fe507..d7e65b27 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,7 @@ a double dash to prevent input files being used as option arguments:
 
 ```
     -h, --help                  Print usage information.
+                                `--help options` for details on available options.
     -V, --version               Print version number.
     -p, --parse <options>       Specify parser options:
                                 `acorn`  Use Acorn for parsing.
@@ -713,14 +714,14 @@ UglifyJS.minify(code, { mangle: { toplevel: true } }).code;
 
 ### Mangle properties options
 
-- `reserved` (default: `[]`) -- Do not mangle property names listed in the 
+- `reserved` (default: `[]`) -- Do not mangle property names listed in the
   `reserved` array.
 - `regex` (default: `null`) -— Pass a RegExp literal to only mangle property
   names matching the regular expression.
 - `keep_quoted` (default: `false`) -— Only mangle unquoted property names.
 - `debug` (default: `false`) -— Mangle names with the original name still present.
   Pass an empty string `""` to enable, or a non-empty string to set the debug suffix.
-- `builtins` (default: `false`) -- Use `true` to allow the mangling of builtin 
+- `builtins` (default: `false`) -- Use `true` to allow the mangling of builtin
   DOM properties. Not recommended to override this setting.
 
 ## Output options
diff --git a/bin/uglifyjs b/bin/uglifyjs
index b9406e1c..a2039f7e 100755
--- a/bin/uglifyjs
+++ b/bin/uglifyjs
@@ -21,7 +21,7 @@ var options = {
     compress: false,
     mangle: false
 };
-program.version(info.name + ' ' + info.version);
+program.version(info.name + " " + info.version);
 program.parseArgv = program.parse;
 program.parse = undefined;
 if (process.argv.indexOf("ast") >= 0) program.helpInformation = UglifyJS.describe_ast;
@@ -30,8 +30,13 @@ else if (process.argv.indexOf("options") >= 0) program.helpInformation = functio
     var options = UglifyJS.default_options();
     for (var option in options) {
         text.push("--" + (option == "output" ? "beautify" : option == "sourceMap" ? "source-map" : option) + " options:");
-        Object.keys(options[option]).forEach(function(name) {
-            text.push("  " + name);
+        var defs = options[option];
+        var padding = "";
+        Object.keys(defs).map(function(name) {
+            if (padding.length < name.length) padding = Array(name.length + 1).join(" ");
+            return [ name, JSON.stringify(defs[name]) ];
+        }).forEach(function(tokens) {
+            text.push("  " + tokens[0] + padding.slice(tokens[0].length - 2) + tokens[1]);
         });
         text.push("");
     }
-- 
2.34.1