use args_conflicts_with_subcommands

Co-authored-by: Copilot <copilot@github.com>

Author: kevinjqliu

tpchgen-cli/bin/main.rs

@@ -55,12 +55,16 @@ tpchgen-cli parquet -s 100 --tables=lineitem --parts=10 --output-dir=/tmp/tpch
 # Generate scale factor one in current directory, seeing debug output
 
 RUST_LOG=debug tpchgen-cli -s 1 --output-dir=/tmp/tpch
-"#
+"#,
+    args_conflicts_with_subcommands = true
 )]
 struct Cli {
     #[command(subcommand)]
     command: Option<Commands>,
 
+    // Top-level args are only used when no subcommand is given (legacy path).
+    // args_conflicts_with_subcommands prevents these from being silently ignored
+    // when a subcommand is present (e.g. `tpchgen-cli -s 10 parquet` is an error).
     #[command(flatten)]
     args: TopLevelArgs,
 }
@@ -296,27 +300,6 @@ impl Cli {
     /// Main function to run the generation
     #[allow(deprecated)]
     async fn main(self) -> io::Result<()> {
-        // Error if deprecated top-level flags are used with a subcommand
-        if self.command.is_some() {
-            if self.args.format.is_some() {
-                return Err(io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    "Cannot use --format with a subcommand. Use the subcommand directly, e.g. `tpchgen-cli parquet`",
-                ));
-            }
-            if self.args.parquet_compression.is_some() {
-                return Err(io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    "Cannot use --parquet-compression with a subcommand. Use `tpchgen-cli parquet --compression=...` instead",
-                ));
-            }
-            if self.args.parquet_row_group_bytes.is_some() {
-                return Err(io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    "Cannot use --parquet-row-group-bytes with a subcommand. Use `tpchgen-cli parquet --row-group-bytes=...` instead",
-                ));
-            }
-        }
         match self.command {
             Some(Commands::Tbl(args)) => args.run().await,
             Some(Commands::Csv(args)) => args.run().await,

tpchgen-cli/tests/cli_integration.rs

@@ -740,7 +740,7 @@ fn test_format_with_subcommand_conflict() {
         .assert()
         .failure()
         .stderr(predicates::str::contains(
-            "Cannot use --format with a subcommand",
+            "cannot be used with",
         ));
 }
 
@@ -763,7 +763,7 @@ fn test_parquet_compression_with_subcommand_conflict() {
         .assert()
         .failure()
         .stderr(predicates::str::contains(
-            "Cannot use --parquet-compression with a subcommand",
+            "cannot be used with",
         ));
 
     // With tbl subcommand
@@ -780,7 +780,7 @@ fn test_parquet_compression_with_subcommand_conflict() {
         .assert()
         .failure()
         .stderr(predicates::str::contains(
-            "Cannot use --parquet-compression with a subcommand",
+            "cannot be used with",
         ));
 }
 
@@ -803,7 +803,7 @@ fn test_parquet_row_group_bytes_with_subcommand_conflict() {
         .assert()
         .failure()
         .stderr(predicates::str::contains(
-            "Cannot use --parquet-row-group-bytes with a subcommand",
+            "cannot be used with",
         ));
 
     // With csv subcommand
@@ -820,10 +820,43 @@ fn test_parquet_row_group_bytes_with_subcommand_conflict() {
         .assert()
         .failure()
         .stderr(predicates::str::contains(
-            "Cannot use --parquet-row-group-bytes with a subcommand",
+            "cannot be used with",
         ));
 }
 
+/// Test that common args before a subcommand are rejected
+#[test]
+fn test_common_args_with_subcommand_conflict() {
+    let temp_dir = tempdir().expect("Failed to create temporary directory");
+
+    // -s before subcommand should error
+    cargo_bin_cmd!("tpchgen-cli")
+        .arg("-s")
+        .arg("0.01")
+        .arg("parquet")
+        .arg("--tables")
+        .arg("part")
+        .arg("--output-dir")
+        .arg(temp_dir.path())
+        .assert()
+        .failure()
+        .stderr(predicates::str::contains(
+            "cannot be used with",
+        ));
+
+    // -s after subcommand should work
+    cargo_bin_cmd!("tpchgen-cli")
+        .arg("parquet")
+        .arg("-s")
+        .arg("0.01")
+        .arg("--tables")
+        .arg("part")
+        .arg("--output-dir")
+        .arg(temp_dir.path())
+        .assert()
+        .success();
+}
+
 /// Test that running with no --format and no subcommand defaults to TBL
 #[test]
 fn test_default_format_is_tbl() {