From 72438ef5bb03d5883b9909dbd5286c38d701c897 Mon Sep 17 00:00:00 2001
From: Chan Kang <ChannyClaus@users.noreply.github.com>
Date: Fri, 28 Jun 2024 18:35:37 -0400
Subject: [PATCH] Use asterisk for dependency cycles in `uv pip tree` (#4626)

## Summary

Use an asterisk to indicate dependency cycles, along with de-duplicated packages.

Purely an aesthetic change.
---
 crates/uv/src/commands/pip/tree.rs | 23 +++++++++--------------
 crates/uv/tests/pip_tree.rs        |  8 ++++----
 2 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/crates/uv/src/commands/pip/tree.rs b/crates/uv/src/commands/pip/tree.rs
index 464bc2be1..8b80213ee 100644
--- a/crates/uv/src/commands/pip/tree.rs
+++ b/crates/uv/src/commands/pip/tree.rs
@@ -57,14 +57,12 @@ pub(crate) fn pip_tree(
     .join("\n");
     writeln!(printer.stdout(), "{rendered_tree}").unwrap();
     if rendered_tree.contains('*') {
-        writeln!(
-            printer.stdout(),
-            "{}",
+        let message = if no_dedupe {
+            "(*) Package tree is a cycle and cannot be shown".italic()
+        } else {
             "(*) Package tree already displayed".italic()
-        )?;
-    }
-    if rendered_tree.contains('#') {
-        writeln!(printer.stdout(), "{}", "(#) Dependency cycle".italic())?;
+        };
+        writeln!(printer.stdout(), "{message}")?;
     }
 
     // Validate that the environment is consistent.
@@ -176,13 +174,10 @@ impl<'a> DisplayDependencyGraph<'a> {
         let is_visited = visited.contains(&package_name);
         let line = format!("{} v{}", package_name, installed_dist.version());
 
-        if path.contains(&package_name) {
-            return vec![format!("{} (#)", line)];
-        }
-
-        // If the package has been visited and de-duplication is enabled (default),
-        // skip the traversal.
-        if is_visited && !self.no_dedupe {
+        // Skip the traversal if
+        // 1. the package is in the current traversal path (i.e. a dependency cycle)
+        // 2. if the package has been visited and de-duplication is enabled (default)
+        if path.contains(&package_name) || (is_visited && !self.no_dedupe) {
             return vec![format!("{} (*)", line)];
         }
 
diff --git a/crates/uv/tests/pip_tree.rs b/crates/uv/tests/pip_tree.rs
index fdaea3f87..7b5a444b9 100644
--- a/crates/uv/tests/pip_tree.rs
+++ b/crates/uv/tests/pip_tree.rs
@@ -623,8 +623,8 @@ fn cyclic_dependency() {
     uv-cyclic-dependencies-c v0.1.0
     └── uv-cyclic-dependencies-a v0.1.0
         └── uv-cyclic-dependencies-b v0.1.0
-            └── uv-cyclic-dependencies-a v0.1.0 (#)
-    (#) Dependency cycle
+            └── uv-cyclic-dependencies-a v0.1.0 (*)
+    (*) Package tree already displayed
 
     ----- stderr -----
     "###
@@ -906,8 +906,8 @@ fn no_dedupe_and_cycle() {
     uv-cyclic-dependencies-c v0.1.0
     └── uv-cyclic-dependencies-a v0.1.0
         └── uv-cyclic-dependencies-b v0.1.0
-            └── uv-cyclic-dependencies-a v0.1.0 (#)
-    (#) Dependency cycle
+            └── uv-cyclic-dependencies-a v0.1.0 (*)
+    (*) Package tree is a cycle and cannot be shown
 
     ----- stderr -----
     "###