Implement "Requires" field in pip show

crates/uv/src/commands/pip_show.rs

@@ -1,3 +1,4 @@
+use std::collections::BTreeSet;
 use std::fmt::Write;
 
 use anyhow::Result;
@@ -62,6 +63,9 @@ pub(crate) fn pip_show(
     // Build the installed index.
     let site_packages = SitePackages::from_executable(&venv)?;
 
+    // Determine the markers to use for resolution.
+    let markers = venv.interpreter().markers();
+
     // Sort and deduplicate the packages, which are keyed by name.
     packages.sort_unstable();
     packages.dedup();
@@ -116,6 +120,19 @@ pub(crate) fn pip_show(
                 .expect("package path is not root")
                 .simplified_display()
         )?;
+
+        let mut requires = distribution
+            .metadata()
+            .unwrap()
+            .requires_dist
+            .into_iter()
+            .filter(|req| req.evaluate_markers(markers, &[]))
+            .map(|req| req.name.to_string())
+            .collect::<BTreeSet<_>>()
+            .into_iter()
+            .collect::<Vec<_>>();
+        requires.sort();
+        writeln!(printer.stdout(), "Requires: {}", requires.join(", "))?;
     }
 
     // Validate that the environment is consistent.

crates/uv/tests/pip_show.rs

@@ -56,6 +56,124 @@ fn show_empty() {
     );
 }
 
+#[test]
+fn show_requires_multiple() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let requirements_txt = context.temp_dir.child("requirements.txt");
+    requirements_txt.touch()?;
+    requirements_txt.write_str("requests==2.31.0")?;
+
+    uv_snapshot!(install_command(&context)
+        .arg("-r")
+        .arg("requirements.txt")
+        .arg("--strict"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 5 packages in [TIME]
+    Downloaded 5 packages in [TIME]
+    Installed 5 packages in [TIME]
+     + certifi==2023.11.17
+     + charset-normalizer==3.3.2
+     + idna==3.4
+     + requests==2.31.0
+     + urllib3==2.1.0
+    "###
+    );
+
+    context.assert_command("import requests").success();
+    let filters = [(
+        r"Location:.*site-packages",
+        "Location: [WORKSPACE_DIR]/site-packages",
+    )]
+    .to_vec();
+
+    // Guards against the package names being sorted.
+    uv_snapshot!(filters, Command::new(get_bin())
+        .arg("pip")
+        .arg("show")
+        .arg("requests")
+        .arg("--cache-dir")
+        .arg(context.cache_dir.path())
+        .env("VIRTUAL_ENV", context.venv.as_os_str())
+        .current_dir(&context.temp_dir), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    Name: requests
+    Version: 2.31.0
+    Location: [WORKSPACE_DIR]/site-packages
+    Requires: certifi, charset-normalizer, idna, urllib3
+
+    ----- stderr -----
+    "###
+    );
+
+    Ok(())
+}
+
+// Asserts python version marker in the metadata is correctly evaluated.
+// click 8.1.7 requires importlib-metadata but only when python_version < "3.8"
+#[test]
+fn show_python_version_marker() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let requirements_txt = context.temp_dir.child("requirements.txt");
+    requirements_txt.touch()?;
+    requirements_txt.write_str("click==8.1.7")?;
+
+    uv_snapshot!(install_command(&context)
+        .arg("-r")
+        .arg("requirements.txt")
+        .arg("--strict"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    Downloaded 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + click==8.1.7
+    "###
+    );
+
+    context.assert_command("import click").success();
+    let mut filters = [(
+        r"Location:.*site-packages",
+        "Location: [WORKSPACE_DIR]/site-packages",
+    )]
+    .to_vec();
+    if cfg!(windows) {
+        filters.push(("Requires: colorama", "Requires: "));
+    }
+
+    uv_snapshot!(filters, Command::new(get_bin())
+        .arg("pip")
+        .arg("show")
+        .arg("click")
+        .arg("--cache-dir")
+        .arg(context.cache_dir.path())
+        .env("VIRTUAL_ENV", context.venv.as_os_str())
+        .current_dir(&context.temp_dir), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    Name: click
+    Version: 8.1.7
+    Location: [WORKSPACE_DIR]/site-packages
+    Requires: 
+
+    ----- stderr -----
+    "###
+    );
+
+    Ok(())
+}
+
 #[test]
 fn show_found_single_package() -> Result<()> {
     let context = TestContext::new("3.12");
@@ -101,6 +219,7 @@ fn show_found_single_package() -> Result<()> {
     Name: markupsafe
     Version: 2.1.3
     Location: [WORKSPACE_DIR]/site-packages
+    Requires: 
 
     ----- stderr -----
     "###
@@ -162,10 +281,12 @@ fn show_found_multiple_packages() -> Result<()> {
     Name: markupsafe
     Version: 2.1.3
     Location: [WORKSPACE_DIR]/site-packages
+    Requires: 
     ---
     Name: pip
     Version: 21.3.1
     Location: [WORKSPACE_DIR]/site-packages
+    Requires: 
 
     ----- stderr -----
     "###
@@ -227,6 +348,7 @@ fn show_found_one_out_of_two() -> Result<()> {
     Name: markupsafe
     Version: 2.1.3
     Location: [WORKSPACE_DIR]/site-packages
+    Requires: 
 
     ----- stderr -----
     warning: Package(s) not found for: flask
@@ -378,6 +500,7 @@ fn show_editable() -> Result<()> {
     Name: poetry-editable
     Version: 0.1.0
     Location: [WORKSPACE_DIR]/site-packages
+    Requires: numpy
 
     ----- stderr -----
     "###