Add some compatibility arguments to `puffin venv` (#1282)

See: https://github.com/astral-sh/puffin/issues/1276.

crates/puffin/src/compat/mod.rs

@@ -3,6 +3,10 @@ use clap::{Args, ValueEnum};
 
 use puffin_warnings::warn_user;
 
+pub(crate) trait CompatArgs {
+    fn validate(&self) -> Result<()>;
+}
+
 /// Arguments for `pip-compile` compatibility.
 ///
 /// These represent a subset of the `pip-compile` interface that Puffin supports by default.
@@ -84,13 +88,13 @@ pub(crate) struct PipCompileCompatArgs {
     pip_args: Option<String>,
 }
 
-impl PipCompileCompatArgs {
+impl CompatArgs for PipCompileCompatArgs {
     /// Validate the arguments passed for `pip-compile` compatibility.
     ///
     /// This method will warn when an argument is passed that has no effect but matches Puffin's
     /// behavior. If an argument is passed that does _not_ match Puffin's behavior (e.g.,
     /// `--no-build-isolation`), this method will return an error.
-    pub(crate) fn validate(&self) -> Result<()> {
+    fn validate(&self) -> Result<()> {
         if self.allow_unsafe {
             warn_user!(
                 "pip-compile's `--allow-unsafe` has no effect (Puffin can safely pin `pip` and other packages)."
@@ -281,13 +285,13 @@ pub(crate) struct PipSyncCompatArgs {
     pip_args: Option<String>,
 }
 
-impl PipSyncCompatArgs {
+impl CompatArgs for PipSyncCompatArgs {
     /// Validate the arguments passed for `pip-sync` compatibility.
     ///
     /// This method will warn when an argument is passed that has no effect but matches Puffin's
     /// behavior. If an argument is passed that does _not_ match Puffin's behavior, this method will
     /// return an error.
-    pub(crate) fn validate(&self) -> Result<()> {
+    fn validate(&self) -> Result<()> {
         if self.ask {
             return Err(anyhow!(
                 "pip-sync's `--ask` is unsupported (Puffin never asks for confirmation)."
@@ -349,3 +353,64 @@ enum AnnotationStyle {
     Line,
     Split,
 }
+
+/// Arguments for `venv` compatibility.
+///
+/// These represent a subset of the `virtualenv` interface that Puffin supports by default.
+#[derive(Args)]
+#[allow(clippy::struct_excessive_bools)]
+pub(crate) struct VenvCompatArgs {
+    #[clap(long, hide = true)]
+    clear: bool,
+
+    #[clap(long, hide = true)]
+    no_seed: bool,
+
+    #[clap(long, hide = true)]
+    no_pip: bool,
+
+    #[clap(long, hide = true)]
+    no_setuptools: bool,
+
+    #[clap(long, hide = true)]
+    no_wheel: bool,
+}
+
+impl CompatArgs for VenvCompatArgs {
+    /// Validate the arguments passed for `venv` compatibility.
+    ///
+    /// This method will warn when an argument is passed that has no effect but matches Puffin's
+    /// behavior. If an argument is passed that does _not_ match Puffin's behavior, this method will
+    /// return an error.
+    fn validate(&self) -> Result<()> {
+        if self.clear {
+            warn_user!(
+                "virtualenv's `--clear` has no effect (Puffin always clears the virtual environment)."
+            );
+        }
+
+        if self.no_seed {
+            warn_user!(
+                "virtualenv's `--no-seed` has no effect (Puffin omits seed packages by default)."
+            );
+        }
+
+        if self.no_pip {
+            warn_user!("virtualenv's `--no-pip` has no effect (Puffin omits `pip` by default).");
+        }
+
+        if self.no_setuptools {
+            warn_user!(
+                "virtualenv's `--no-setuptools` has no effect (Puffin omits `setuptools` by default)."
+            );
+        }
+
+        if self.no_wheel {
+            warn_user!(
+                "virtualenv's `--no-wheel` has no effect (Puffin omits `wheel` by default)."
+            );
+        }
+
+        Ok(())
+    }
+}

crates/puffin/src/main.rs

@@ -21,6 +21,7 @@ use puffin_traits::{NoBuild, PackageNameSpecifier, SetupPyStrategy};
 use requirements::ExtrasSpecification;
 
 use crate::commands::{extra_name_with_clap_error, ExitStatus, Upgrade};
+use crate::compat::CompatArgs;
 use crate::requirements::RequirementsSource;
 
 #[cfg(target_os = "windows")]
@@ -625,6 +626,9 @@ struct VenvArgs {
     /// format (e.g., `2006-12-02`).
     #[arg(long, value_parser = date_or_datetime, hide = true)]
     exclude_newer: Option<DateTime<Utc>>,
+
+    #[command(flatten)]
+    compat_args: compat::VenvCompatArgs,
 }
 
 #[derive(Args)]
@@ -928,6 +932,8 @@ async fn run() -> Result<ExitStatus> {
         }) => commands::freeze(&cache, args.strict, printer),
         Commands::Clean(args) => commands::clean(&cache, &args.package, printer),
         Commands::Venv(args) => {
+            args.compat_args.validate()?;
+
             let index_locations = IndexLocations::from_args(
                 args.index_url,
                 args.extra_index_url,

crates/puffin/tests/venv.rs

@@ -443,3 +443,47 @@ fn non_empty_dir_exists() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn virtualenv_compatibility() -> Result<()> {
+    let temp_dir = assert_fs::TempDir::new()?;
+    let cache_dir = assert_fs::TempDir::new()?;
+    let bin = create_bin_with_executables(&temp_dir, &["3.12"]).expect("Failed to create bin dir");
+    let venv = temp_dir.child(".venv");
+
+    // Create a virtual environment at `.venv`, passing the redundant `--clear` flag.
+    let filter_venv = regex::escape(&venv.normalized_display().to_string());
+    let filters = &[
+        (
+            r"Using Python 3\.\d+\.\d+ interpreter at .+",
+            "Using Python [VERSION] interpreter at [PATH]",
+        ),
+        (&filter_venv, "/home/ferris/project/.venv"),
+    ];
+    puffin_snapshot!(filters, Command::new(get_bin())
+        .arg("venv")
+        .arg(venv.as_os_str())
+        .arg("--clear")
+        .arg("--python")
+        .arg("3.12")
+        .arg("--cache-dir")
+        .arg(cache_dir.path())
+        .arg("--exclude-newer")
+        .arg(EXCLUDE_NEWER)
+        .env("PUFFIN_TEST_PYTHON_PATH", bin.clone())
+        .current_dir(&temp_dir), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: virtualenv's `--clear` has no effect (Puffin always clears the virtual environment).
+    Using Python [VERSION] interpreter at [PATH]
+    Creating virtualenv at: /home/ferris/project/.venv
+    "###
+    );
+
+    venv.assert(predicates::path::is_dir());
+
+    Ok(())
+}