From db4da68618e8896cffa6b5164991308029160eb4 Mon Sep 17 00:00:00 2001
From: Sergey Bugaev <bugaevc@serenityos.org>
Date: Thu, 26 Mar 2020 10:03:17 +0300
Subject: [PATCH] Base: Add a man page for js(1)

This also changes --ast-dump to --dump-ast, because I like it better
and that is what the variable is actually called.
---
 Base/usr/share/man/man1/js.md | 45 +++++++++++++++++++++++++++++++++++
 Userland/js.cpp               |  2 +-
 2 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 Base/usr/share/man/man1/js.md

diff --git a/Base/usr/share/man/man1/js.md b/Base/usr/share/man/man1/js.md
new file mode 100644
index 0000000000..1680e42f1d
--- /dev/null
+++ b/Base/usr/share/man/man1/js.md
@@ -0,0 +1,45 @@
+## Name
+
+js - evaluate JavaScript
+
+## Synopsis
+
+```**sh
+$ js [options...] [script.js]
+```
+
+## Description
+
+`js` evaluates JavaScript programs using the LibJS engine. If you pass it a path
+to a script file, it will execute that script. Otherwise, it enters the
+Read-Eval-Print-Loop (REPL) mode, where it interactively reads pieces (usually,
+single lines) of code from standard input, evaluates them in one shared
+interpreter context, and prints back their results. This mode is useful for
+quickly experimenting with LibJS.
+
+## Options
+
+* `-A`, `--dump-ast`: Dump the Abstract Syntax Tree after parsing the program.
+* `-l`, `--print-last-result`: Print the result of the last statement executed.
+* `-g`, `--gc-on-every-allocation`: Run garbage collection on every allocation.
+
+## Examples
+
+Here's how you execute a script:
+
+```sh
+$ js ~/js/type-play.js
+```
+
+And here's an example of an interactive REPL session:
+
+```js
+$ js
+> function log_sum(a, b) {
+.     console.log(a + b)
+. }
+[object ScriptFunction]
+> log_sum(35, 42)
+77
+undefined
+```
diff --git a/Userland/js.cpp b/Userland/js.cpp
index c3db8206b5..f13cb9204b 100644
--- a/Userland/js.cpp
+++ b/Userland/js.cpp
@@ -115,7 +115,7 @@ int main(int argc, char** argv)
     const char* script_path = nullptr;
 
     Core::ArgsParser args_parser;
-    args_parser.add_option(dump_ast, "Dump the AST", "ast-dump", 'A');
+    args_parser.add_option(dump_ast, "Dump the AST", "dump-ast", 'A');
     args_parser.add_option(print_last_result, "Print last result", "print-last-result", 'l');
     args_parser.add_option(gc_on_every_allocation, "GC on every allocation", "gc-on-every-allocation", 'g');
     args_parser.add_positional_argument(script_path, "Path to script file", "script", Core::ArgsParser::Required::No);