feat(tscn-to-bsn): add global help fallback support

Add a fallback module providing a help command that displays usage
information for the tool.

4 files changed, 31 insertions, 0 deletions

diff --git a/tools/tscn-to-bsn/src/bin/tscn2bsn.rs b/tools/tscn-to-bsn/src/bin/tscn2bsn.rs
index 4ac1f5a..84d6444 100644
--- a/tools/tscn-to-bsn/src/bin/tscn2bsn.rs
+++ b/tools/tscn-to-bsn/src/bin/tscn2bsn.rs
@@ -1,4 +1,5 @@
 use mingling::picker::parselib::{ParserStyle, WINDOWS_STYLE};
+use mingling::setup::picker::HelpFlagSetup;
 use tscn_to_bsn::ThisProgram;
 use tscn_to_bsn::cmd::CommandsSetup;
 use tscn_to_bsn::res::gd_proj_dir::GodotProjectSetup;
@@ -8,6 +9,7 @@ fn main() {
 
     ParserStyle::set_global_style(&WINDOWS_STYLE);
 
+    program.with_setup(HelpFlagSetup::default());
     program.with_setup(CommandsSetup);
     program.with_setup(GodotProjectSetup);
 
diff --git a/tools/tscn-to-bsn/src/fallback.rs b/tools/tscn-to-bsn/src/fallback.rs
new file mode 100644
index 0000000..99bdd13
--- /dev/null
+++ b/tools/tscn-to-bsn/src/fallback.rs
@@ -0,0 +1,13 @@
+use mingling::macros::{help, renderer};
+
+use crate::EntryFallback;
+
+#[help]
+pub fn help_global(_: EntryFallback) -> String {
+    include_str!("helps/help.txt").to_string()
+}
+
+#[renderer]
+pub fn render_global_hint(_: EntryFallback) -> String {
+    "Error: unknown command, please use `tscn2bsn /H` for help".into()
+}
diff --git a/tools/tscn-to-bsn/src/helps/help.txt b/tools/tscn-to-bsn/src/helps/help.txt
new file mode 100644
index 0000000..3f9c7c2
--- /dev/null
+++ b/tools/tscn-to-bsn/src/helps/help.txt
@@ -0,0 +1,15 @@
+A simple program for translating Godot 4's TSCN (*.tscn) files
+                     into Bevy 0.19's bsn! macro invocation code.
+
+USAGE: tscn2bsn [] <ARGS..>
+
+Flags:
+  /H /Help                              Show this text
+  /P /ProjectPath <DIR_PATH>            Godot project path
+
+Commands:
+  convert /I <TSCN_FILE> /O <RON_FILE>  Parse TSCN text into a syntax tree and
+                                        output it to a RON file.
+
+  build-cache                           Collect information about the current
+                                        project and build a cache for analysis.
diff --git a/tools/tscn-to-bsn/src/lib.rs b/tools/tscn-to-bsn/src/lib.rs
index d243e10..b2d80aa 100644
--- a/tools/tscn-to-bsn/src/lib.rs
+++ b/tools/tscn-to-bsn/src/lib.rs
@@ -2,6 +2,7 @@ use mingling::macros::gen_program;
 
 pub mod cmd;
 pub mod err;
+pub mod fallback;
 pub mod gd_res_structure;
 pub mod res;