Refactor help command and add tests

shout-rs/src/main.rs

@@ -77,11 +77,30 @@ fn print_test_help() {
 fn parse_args() -> Option<(&'static str, TestOpts)> {
     let args: Vec<String> = std::env::args().skip(1).collect();
 
-    if args.is_empty() || args[0] == "-h" || args[0] == "--help" || args[0] == "help" {
+    if args.is_empty() || args[0] == "-h" || args[0] == "--help" {
         print_usage();
         process::exit(if args.is_empty() { 1 } else { 0 });
     }
 
+    if args[0] == "help" {
+        if args.len() < 2 {
+            print_usage();
+        } else {
+            match args[1].as_str() {
+                "test" => print_test_help(),
+                "example" => print_example_help(),
+                "version" => print_version_help(),
+                "help" => print_help_help(),
+                other => {
+                    eprintln!("Unknown command: {other}");
+                    eprintln!("Run 'shout --help' for usage");
+                    process::exit(1);
+                }
+            }
+        }
+        process::exit(0);
+    }
+
     let subcommand = args[0].as_str();
 
     match subcommand {
@@ -463,6 +482,24 @@ fn pathdiff(path: &Path, base: &Path) -> String {
     }
 }
 
+fn print_example_help() {
+    eprintln!("Usage: shout example");
+    eprintln!();
+    eprintln!("Print an example .shout file");
+}
+
+fn print_version_help() {
+    eprintln!("Usage: shout version");
+    eprintln!();
+    eprintln!("Print the version");
+}
+
+fn print_help_help() {
+    eprintln!("Usage: shout help [command]");
+    eprintln!();
+    eprintln!("Display help for command");
+}
+
 fn print_example() {
     println!(
         r#"# Example .shout file

shout-rs/tests/shout.rs

@@ -0,0 +1,16 @@
+use std::process::Command;
+
+fn shout() -> Command {
+    let mut cmd = Command::new(env!("CARGO_BIN_EXE_shout"));
+    cmd.current_dir(concat!(env!("CARGO_MANIFEST_DIR")));
+    cmd
+}
+
+#[test]
+fn test_suite_passes() {
+    let status = shout()
+        .args(["test", "test/"])
+        .status()
+        .unwrap();
+    assert!(status.success(), "shout test test/ exited with {status}");
+}