fix(qsvdp): only list commands actually compiled into the binary (#3816) (#3819)

qsvdp's COMMAND_LIST was a static string that unconditionally advertised
joinp/luau/pivotp/sqlp even when the polars/luau features weren't compiled
in, while the Command enum and dispatch already gated them. Replace it with
a runtime-built `build_command_list()` (mirroring src/main.rs) that emits
those entries — and the 🐻‍❄️/👑 legend lines — only when the corresponding
feature is enabled. Used at both call sites (--list and the bare-qsvdp
"Please choose one" message).

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jqnatividad

src/maindp.rs

@@ -54,8 +54,46 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
 #[global_allocator]
 static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
 
-static COMMAND_LIST: &str = r#"
-    applydp     Apply series of transformations to a column
+mod clitypes;
+mod cmd;
+mod config;
+mod index;
+mod lookup;
+mod odhtcache;
+mod select;
+mod util;
+
+static USAGE: &str = r#"
+Usage:
+    qsvdp <command> [<args>...]
+    qsvdp [options]
+
+Options:
+    --list               List all commands available.
+    --envlist            List all qsv-relevant environment variables.
+    -u, --update         Check for the latest qsv release.
+    -U, --updatenow      Update qsv to the latest release from GitHub without confirming.
+    -h, --help           Display this message
+    <command> -h         Display the command help message
+    -v, --version        Print version info, mem allocator, features installed, 
+                         max_jobs, num_cpus, build info then exit"#;
+#[derive(Deserialize)]
+struct Args {
+    arg_command:    Option<Command>,
+    flag_list:      bool,
+    flag_envlist:   bool,
+    flag_update:    bool,
+    flag_updatenow: bool,
+}
+
+/// Build the "Installed commands:" listing dynamically so feature-gated commands
+/// (joinp/pivotp/sqlp under `polars`, luau under `luau`) only appear when
+/// actually compiled in. The `Command` enum and dispatch already gate these;
+/// the help text must match.
+fn build_command_list() -> String {
+    let mut enabled_commands = String::from("\n");
+    enabled_commands.push_str(
+        "    applydp     Apply series of transformations to a column
     blake3      Compute BLAKE3 cryptographic hashes of files
     count       Count records
     datefmt     Format date/datetime strings
@@ -72,12 +110,22 @@ static COMMAND_LIST: &str = r#"
     help        Show this usage message
     index       Create CSV index for faster access
     input       Read CSVs w/ special quoting, skipping, trimming & transcoding rules
-    join        Join CSV files
-    joinp       Join CSV files using the Pola.rs engine 🐻‍❄️
-    luau        Execute Luau script on CSV data 👑
-    moarstats   Add "moar" statistics to existing stats CSV
-    pivotp      Pivot CSV data 🐻‍❄️
-    pragmastat  Pragmatic statistical toolkit
+    join        Join CSV files\n",
+    );
+
+    #[cfg(feature = "polars")]
+    enabled_commands.push_str("    joinp       Join CSV files using the Pola.rs engine 🐻‍❄️\n");
+
+    #[cfg(feature = "luau")]
+    enabled_commands.push_str("    luau        Execute Luau script on CSV data 👑\n");
+
+    enabled_commands.push_str("    moarstats   Add \"moar\" statistics to existing stats CSV\n");
+
+    #[cfg(feature = "polars")]
+    enabled_commands.push_str("    pivotp      Pivot CSV data 🐻‍❄️\n");
+
+    enabled_commands.push_str(
+        "    pragmastat  Pragmatic statistical toolkit
     pseudo      Pseudonymise the values of a column
     rename      Rename the columns of CSV data efficiently
     replace     Replace patterns in CSV data
@@ -91,46 +139,30 @@ static COMMAND_LIST: &str = r#"
     snappy      Compress/decompress data using the Snappy algorithm
     sniff       Quickly sniff CSV metadata
     sort        Sort CSV data in alphabetical, numerical, reverse or random order
-    sortcheck   Check if a CSV is sorted
-    sqlp        Run a SQL query against several CSVs using the Pola.rs engine 🐻‍❄️
-    stats       Infer data types and compute summary statistics
+    sortcheck   Check if a CSV is sorted\n",
+    );
+
+    #[cfg(feature = "polars")]
+    enabled_commands.push_str(
+        "    sqlp        Run a SQL query against several CSVs using the Pola.rs engine 🐻‍❄️\n",
+    );
+
+    enabled_commands.push_str(
+        "    stats       Infer data types and compute summary statistics
     template    Render templates using CSV data
-    validate    Validate CSV data for RFC4180-compliance or with JSON Schema
+    validate    Validate CSV data for RFC4180-compliance or with JSON Schema\n",
+    );
 
-    NOTE: qsvdp ignores the --progressbar option for all commands.
-          🐻‍❄️ - requires polars feature
-          👑 - requires luau feature"#;
+    enabled_commands
+        .push_str("\n    NOTE: qsvdp ignores the --progressbar option for all commands.");
 
-mod clitypes;
-mod cmd;
-mod config;
-mod index;
-mod lookup;
-mod odhtcache;
-mod select;
-mod util;
+    #[cfg(feature = "polars")]
+    enabled_commands.push_str("\n          🐻‍❄️ - requires polars feature");
 
-static USAGE: &str = r#"
-Usage:
-    qsvdp <command> [<args>...]
-    qsvdp [options]
+    #[cfg(feature = "luau")]
+    enabled_commands.push_str("\n          👑 - requires luau feature");
 
-Options:
-    --list               List all commands available.
-    --envlist            List all qsv-relevant environment variables.
-    -u, --update         Check for the latest qsv release.
-    -U, --updatenow      Update qsv to the latest release from GitHub without confirming.
-    -h, --help           Display this message
-    <command> -h         Display the command help message
-    -v, --version        Print version info, mem allocator, features installed, 
-                         max_jobs, num_cpus, build info then exit"#;
-#[derive(Deserialize)]
-struct Args {
-    arg_command:    Option<Command>,
-    flag_list:      bool,
-    flag_envlist:   bool,
-    flag_update:    bool,
-    flag_updatenow: bool,
+    enabled_commands
 }
 
 fn main() -> QsvExitCode {
@@ -160,7 +192,11 @@ fn main() -> QsvExitCode {
     }
 
     if args.flag_list {
-        wout!("Installed commands:{}\n\n{}", COMMAND_LIST, SPONSOR_MESSAGE);
+        wout!(
+            "Installed commands:{}\n\n{}",
+            build_command_list(),
+            SPONSOR_MESSAGE
+        );
         util::log_end(qsv_args, now);
         return QsvExitCode::Good;
     } else if args.flag_envlist {
@@ -178,10 +214,11 @@ fn main() -> QsvExitCode {
     }
     match args.arg_command {
         None => {
+            let command_list = build_command_list();
             werr!(
                 "qsvdp is a suite of CSV command line utilities optimized for \
                  Datapusher+.\n\nPlease choose one of the following \
-                 commands:\n{COMMAND_LIST}\n\n{SPONSOR_MESSAGE}",
+                 commands:\n{command_list}\n\n{SPONSOR_MESSAGE}",
             );
 
             util::log_end(qsv_args, now);