feat(prqlc cli)!: prqlc with no argument will display help without …

…error (#5133)
PRQL · Jan 30, 2025 · 30f80f1 · 30f80f1
1 parent 566f438
commit 30f80f1
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Showing 2 changed files with 55 additions and 22 deletions.
diff --git a/prqlc/prqlc/src/cli/mod.rs b/prqlc/prqlc/src/cli/mod.rs
@@ -41,7 +41,7 @@ mod watch;
 
 /// Entrypoint called by [`crate::main`]
 pub fn main() -> color_eyre::eyre::Result<()> {
-    let mut cli = Cli::parse();
+    let cli = Cli::parse();
 
     // redirect all log messages into the [debug::DebugLog]
     if has_debug_log(&cli) {
@@ -54,24 +54,28 @@ pub fn main() -> color_eyre::eyre::Result<()> {
     color_eyre::install()?;
     cli.color.write_global();
 
-    if let Err(error) = cli.command.run() {
-        eprintln!("{error}");
-        // Copied from
-        // https://doc.rust-lang.org/src/std/backtrace.rs.html#1-504, since it's private
-        fn backtrace_enabled() -> bool {
-            match env::var("RUST_LIB_BACKTRACE") {
-                Ok(s) => s != "0",
-                Err(_) => match env::var("RUST_BACKTRACE") {
+    if let Some(mut subcommand) = cli.command {
+        if let Err(error) = subcommand.run() {
+            eprintln!("{error}");
+            // Copied from
+            // https://doc.rust-lang.org/src/std/backtrace.rs.html#1-504, since it's private
+            fn backtrace_enabled() -> bool {
+                match env::var("RUST_LIB_BACKTRACE") {
                     Ok(s) => s != "0",
-                    Err(_) => false,
-                },
+                    Err(_) => match env::var("RUST_BACKTRACE") {
+                        Ok(s) => s != "0",
+                        Err(_) => false,
+                    },
+                }
+            }
+            if backtrace_enabled() {
+                eprintln!("{:#}", error.backtrace());
             }
-        }
-        if backtrace_enabled() {
-            eprintln!("{:#}", error.backtrace());
-        }
 
-        exit(1)
+            exit(1)
+        }
+    } else {
+        Cli::command().print_help()?;
     }
 
     Ok(())
@@ -80,7 +84,7 @@ pub fn main() -> color_eyre::eyre::Result<()> {
 #[derive(Parser, Debug, Clone)]
 struct Cli {
     #[command(subcommand)]
-    command: Command,
+    command: Option<Command>,
     #[command(flatten)]
     color: colorchoice_clap::Color,
 }
@@ -533,10 +537,10 @@ impl Command {
 fn has_debug_log(cli: &Cli) -> bool {
     matches!(
         cli.command,
-        Command::Compile {
+        Some(Command::Compile {
             debug_log: Some(_),
             ..
-        }
+        })
     )
 }
 

diff --git a/prqlc/prqlc/src/cli/test.rs b/prqlc/prqlc/src/cli/test.rs
@@ -13,11 +13,11 @@ use walkdir::WalkDir;
 #[cfg(not(windows))] // Windows has slightly different output (e.g. `prqlc.exe`), so we exclude.
 #[test]
 fn help() {
-    assert_cmd_snapshot!(prqlc_command().arg("--help"), @r#"
+    assert_cmd_snapshot!(prqlc_command().arg("--help"), @r"
     success: true
     exit_code: 0
     ----- stdout -----
-    Usage: prqlc [OPTIONS] <COMMAND>
+    Usage: prqlc [OPTIONS] [COMMAND]
 
     Commands:
       parse             Parse into PL AST
@@ -39,7 +39,36 @@ fn help() {
       -V, --version       Print version
 
     ----- stderr -----
-    "#);
+    ");
+
+    // without arguments
+    assert_cmd_snapshot!(prqlc_command(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    Usage: prqlc [OPTIONS] [COMMAND]
+
+    Commands:
+      parse             Parse into PL AST
+      lex               Lex into Lexer Representation
+      fmt               Parse & generate PRQL code back
+      collect           Parse the whole project and collect it into a single PRQL source file
+      debug             Commands for meant for debugging, prone to change
+      experimental      Experimental commands are prone to change
+      compile           Parse, resolve, lower into RQ & compile to SQL
+      watch             Watch a directory and compile .prql files to .sql files
+      list-targets      Show available compile target names
+      shell-completion  Print a shell completion for supported shells
+      help              Print this message or the help of the given subcommand(s)
+
+    Options:
+          --color <WHEN>  Controls when to use color [default: auto] [possible values: auto, always,
+                          never]
+      -h, --help          Print help
+      -V, --version       Print version
+
+    ----- stderr -----
+    ");
 }
 
 #[test]