feat: basic --help support

cli/src/cli/bash.rs

@@ -9,19 +9,27 @@ use miette::IntoDiagnostic;
 use usage::Spec;
 
 #[derive(Debug, Args)]
-#[clap()]
+#[clap(disable_help_flag = true)]
 pub struct Bash {
     script: PathBuf,
     /// arguments to pass to script
     #[clap(allow_hyphen_values = true)]
     args: Vec<String>,
+
+    #[clap(short, long)]
+    help: bool,
 }
 
 impl Bash {
     pub fn run(&mut self) -> miette::Result<()> {
         let (spec, _script) = Spec::parse_file(&self.script)?;
         let mut args = self.args.clone();
         args.insert(0, spec.bin.clone());
+
+        if self.help {
+            return self.help(&spec, &args);
+        }
+
         let parsed = usage::parse::parse(&spec, &args)?;
 
         let mut cmd = std::process::Command::new("bash");
@@ -44,4 +52,9 @@ impl Bash {
 
         Ok(())
     }
+
+    pub fn help(&self, spec: &Spec, _args: &[String]) -> miette::Result<()> {
+        println!("{}", usage::docs::cli::render_help(spec));
+        Ok(())
+    }
 }

examples/multicmd

@@ -0,0 +1,17 @@
+#!/usr/bin/env -S usage bash
+#USAGE cmd "apply" {
+#USAGE   arg "<file>"
+#USAGE }
+#USAGE cmd "select" {}
+
+function apply() {
+  echo "Applying theme $1"
+}
+function select_theme() {
+  echo "Selecting theme $1"
+}
+
+case "$1" in
+"apply") apply "$2" ;;
+"select") select_theme "$2" ;;
+esac

lib/src/docs/cli/mod.rs

@@ -0,0 +1,33 @@
+use crate::Spec;
+use once_cell::sync::Lazy;
+use tera::Tera;
+
+pub fn render_help(spec: &Spec) -> String {
+    let mut ctx = tera::Context::new();
+    ctx.insert("spec", spec);
+    TERA.render("spec_template.md.tera", &ctx)
+        .unwrap()
+        .trim()
+        .to_string()
+        + "\n"
+}
+
+static TERA: Lazy<Tera> = Lazy::new(|| {
+    let mut tera = Tera::default();
+
+    #[rustfmt::skip]
+    tera.add_raw_templates([
+        ("spec_template.md.tera", include_str!("templates/spec_template.tera")),
+    ]).unwrap();
+
+    // tera.register_filter(
+    //     "repeat",
+    //     move |value: &tera::Value, args: &HashMap<String, tera::Value>| {
+    //         let value = value.as_str().unwrap();
+    //         let count = args.get("count").unwrap().as_u64().unwrap();
+    //         Ok(value.repeat(count as usize).into())
+    //     },
+    // );
+
+    tera
+});

lib/src/docs/cli/templates/spec_template.tera

@@ -0,0 +1,31 @@
+{%- if spec.about_long %}{{ spec.about_long }}
+
+{% elif spec.about %}{{ spec.about }}
+
+{% endif %}
+Usage: {{ spec.bin ~ " " ~ spec.cmd.usage | trim }}
+
+{%- if spec.cmd.subcommands %}
+
+Commands:
+{%- for name, cmd in spec.cmd.subcommands %}
+  {{ cmd.usage | trim }}{% if cmd.aliases %}  [aliases: {{ cmd.aliases | join(sep=", ") }}]{% endif %}
+{%- endfor %}
+  help           Print this message or the help of the given subcommand(s)
+{%- endif %}
+
+{%- if spec.cmd.args %}
+
+Arguments:
+{%- for arg in spec.cmd.args %}
+  {{ arg.usage | trim }}
+{%- endfor %}
+{%- endif %}
+
+{%- if spec.cmd.flags %}
+
+Flags:
+{%- for flag in spec.cmd.flags %}
+  {{ flag.usage | trim }}{% if flag.aliases %}  [aliases: {{ flag.aliases | join(sep=", ") }}]{% endif %}
+{%- endfor %}
+{%- endif %}

lib/src/docs/mod.rs

@@ -1 +1,2 @@
+pub mod cli;
 pub mod markdown;