fix(uv): tree --invert silently drops leaf cycles#3
Open
beast-ofcourse wants to merge 3 commits into
Open
Conversation
|
No actionable comments were generated in the recent review. 🎉 ℹ️ Recent review info⚙️ Run configurationConfiguration used: defaults Review profile: CHILL Plan: Pro Plus Run ID: 📒 Files selected for processing (1)
🚧 Files skipped from review as they are similar to previous changes (1)
📝 WalkthroughWalkthroughModifies inverted-mode dependency tree root computation to fall back to Tarjan SCCs when no zero-incoming-edge roots exist, and adds a regression test for an inverted tree containing a leaf cycle. ChangesCycle-aware Root Detection
Estimated code review effort: 2 (Simple) | ~10 minutes 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches📝 Generate docstrings
🧪 Generate unit tests (beta)
Comment |
![coderabbitai[bot]](https://avatars.githubusercontent.com/in/347564?s=60&v=4){kind=small}
There was a problem hiding this comment.
Actionable comments posted: 1
🤖 Prompt for all review comments with AI agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
Inline comments:
In `@crates/uv-resolver/src/lock/tree.rs`:
- Around line 451-474: The root selection logic in tree.rs currently only runs
the SCC fallback when roots is empty, so a graph with any zero-incoming node can
still skip a separate source SCC like a leaf cycle. Update the root discovery in
the invert-mode path around tarjan_scc/roots so every SCC with no external
incoming edges is added as a root regardless of whether other roots already
exist, and keep the package-over-Root preference when choosing the
representative node. Add a mixed acyclic plus leaf-cycle test covering render()
to verify the cycle component is not dropped.
🪄 Autofix (Beta)
Fix all unresolved CodeRabbit comments on this PR:
- Push a commit to this branch (recommended)
- Create a new PR with the fixes
ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro Plus
Run ID: 410539fd-9b2e-467c-99aa-b1a528f33b2d
📒 Files selected for processing (1)
crates/uv-resolver/src/lock/tree.rs
Comment on lines
+451
to
+474
| // If no node has zero incoming edges (e.g., a leaf cycle), fall | ||
| // back to treating each root SCC as a root. A root SCC is one | ||
| // whose nodes have no incoming edges from outside the SCC. | ||
| if roots.is_empty() { | ||
| let sccs = tarjan_scc(&graph); | ||
| for scc in &sccs { | ||
| let has_external_incoming = scc.iter().any(|node| { | ||
| graph | ||
| .edges_directed(*node, Direction::Incoming) | ||
| .any(|edge| !scc.contains(&edge.source())) | ||
| }); | ||
| if !has_external_incoming { | ||
| // Pick the best node in the SCC as root: prefer | ||
| // packages over Root nodes. | ||
| let root = scc | ||
| .iter() | ||
| .find(|n| matches!(graph[**n], Node::Package(_))) | ||
| .or_else(|| scc.first()); | ||
| if let Some(root) = root { | ||
| roots.push(*root); | ||
| } | ||
| } | ||
| } | ||
| } |
There was a problem hiding this comment.
🎯 Functional Correctness | 🟠 Major | ⚡ Quick win
🧩 Analysis chain
🏁 Script executed:
sed -n '1,260p' crates/uv-resolver/src/lock/tree.rsRepository: beast-ofcourse/uv
Length of output: 10717
🏁 Script executed:
rg -n "tarjan_scc|roots\.is_empty\(|render\(|leaf cycle|SCC|zero incoming|incoming edges" crates/uv-resolver/src/lock/tree.rs crates/uv-resolver/src -g '!target'Repository: beast-ofcourse/uv
Length of output: 2059
🏁 Script executed:
fd -a -t f crates/uv-resolver/src/lockRepository: beast-ofcourse/uv
Length of output: 569
🏁 Script executed:
#!/bin/bash
set -euo pipefail
echo '--- tree.rs outline ---'
ast-grep outline crates/uv-resolver/src/lock/tree.rs --view expanded || true
echo '--- relevant lines ---'
nl -ba crates/uv-resolver/src/lock/tree.rs | sed -n '380,520p'
echo '--- tests and references ---'
rg -n "tree::|render\(|tarjan_scc|leaf cycle|roots\.is_empty\(|source SCC|zero incoming" crates/uv-resolver/src -g '!target'Repository: beast-ofcourse/uv
Length of output: 2372
🏁 Script executed:
#!/bin/bash
set -euo pipefail
echo '--- surrounding code ---'
nl -ba crates/uv-resolver/src/lock/tree.rs | sed -n '420,500p'
echo '--- search for tests covering mixed graphs / leaf cycles ---'
rg -n "leaf cycle|cycle.*leaf|mixed graph|source SCC|tarjan_scc|roots\.is_empty\(|zero incoming" crates/uv-resolver -g '!target' -g '*.rs'Repository: beast-ofcourse/uv
Length of output: 220
🏁 Script executed:
#!/bin/bash
set -euo pipefail
python3 - <<'PY'
from pathlib import Path
import re
path = Path('crates/uv-resolver/src/lock/tree.rs')
text = path.read_text()
# Extract the root-selection block for inspection
m = re.search(r'let mut roots: Vec<_> = graph.*?roots\s*$', text, re.S | re.M)
print('found_block=', bool(m))
print('contains_roots_is_empty=', 'roots.is_empty()' in text)
print('contains_tarjan_scc=', 'tarjan_scc(&graph)' in text)
print('contains_scc_contains=', '.contains(&edge.source())' in text)
PYRepository: beast-ofcourse/uv
Length of output: 257
🏁 Script executed:
python3 - <<'PY'
from pathlib import Path
path = Path('crates/uv-resolver/src/lock/tree.rs')
lines = path.read_text().splitlines()
for start, end, label in [
(420, 490, 'root selection'),
(700, 760, 'render'),
(920, 1030, 'fmt + tests tail'),
]:
print(f'\n--- {label} ({start}-{end}) ---')
for i in range(start-1, min(end, len(lines))):
print(f'{i+1:4d}: {lines[i]}')
PYRepository: beast-ofcourse/uv
Length of output: 6839
🏁 Script executed:
python3 - <<'PY'
from pathlib import Path
import re
path = Path('crates/uv-resolver/src/lock/tree.rs')
lines = path.read_text().splitlines()
print('--- test function names in tree.rs ---')
for i, line in enumerate(lines, 1):
if re.match(r'\s*fn\s+test_|^\s*#\[test\]', line):
print(f'{i}: {line}')
print('\n--- occurrences of render() in tests section ---')
for i, line in enumerate(lines, 1):
if 'render()' in line or 'TreeDisplay::new' in line:
print(f'{i}: {line}')
PYRepository: beast-ofcourse/uv
Length of output: 285
🏁 Script executed:
python3 - <<'PY'
from pathlib import Path
lines = Path('crates/uv-resolver/src/lock/tree.rs').read_text().splitlines()
for start, end in [(420, 490), (700, 760), (980, 1120)]:
print(f'\n--- lines {start}-{end} ---')
for i in range(start-1, min(end, len(lines))):
print(f'{i+1:4d}: {lines[i]}')
PYRepository: beast-ofcourse/uv
Length of output: 6182
🏁 Script executed:
python3 - <<'PY'
from pathlib import Path
import re
lines = Path('crates/uv-resolver/src/lock/tree.rs').read_text().splitlines()
# Print the root-selection block and render() implementation.
for start, end, label in [
(435, 490, 'root-selection block'),
(707, 760, 'render'),
(1000, 1180, 'tests/nearby examples'),
]:
print(f'\n--- {label} ({start}-{end}) ---')
for i in range(start-1, min(end, len(lines))):
print(f'{i+1:4d}: {lines[i]}')
print('\n--- test markers in file ---')
for i, line in enumerate(lines, 1):
if '#[test]' in line:
print(f'{i}: {line}')
PYRepository: beast-ofcourse/uv
Length of output: 5408
🏁 Script executed:
python3 - <<'PY'
from pathlib import Path
import re
text = Path('crates/uv-resolver/src/lock/tree.rs').read_text()
# Look for tests or fixtures exercising rendering of disconnected / cyclic graphs.
patterns = [
r'leaf cycle',
r'mixed graph',
r'roots\.is_empty\(',
r'tarjan_scc',
r'Render',
r'TreeDisplay::new\(',
]
for pat in patterns:
print(f'\n--- matches for {pat!r} ---')
for m in re.finditer(pat, text):
line = text.count('\n', 0, m.start()) + 1
print(line)
PYRepository: beast-ofcourse/uv
Length of output: 388
Treat every source SCC as a root in invert mode
roots.is_empty() skips the SCC fallback as soon as any zero-incoming node exists, so a separate leaf-cycle component in a mixed graph never becomes a root and render() drops it. Merge the source-SCC pass into the initial root selection and add a mixed acyclic + leaf-cycle test.
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@crates/uv-resolver/src/lock/tree.rs` around lines 451 - 474, The root
selection logic in tree.rs currently only runs the SCC fallback when roots is
empty, so a graph with any zero-incoming node can still skip a separate source
SCC like a leaf cycle. Update the root discovery in the invert-mode path around
tarjan_scc/roots so every SCC with no external incoming edges is added as a root
regardless of whether other roots already exist, and keep the package-over-Root
preference when choosing the representative node. Add a mixed acyclic plus
leaf-cycle test covering render() to verify the cycle component is not dropped.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
When the dependency graph has a leaf cycle (a group of packages that depend on each other with nothing depending on them from outside), \uv tree --invert\ would produce no output at all because every node in the reversed graph has at least one incoming edge, leaving the root set empty.
This adds a fallback: when no root is found via the standard zero-incoming-edges check, strongly connected components (SCCs) are computed using Tarjan's algorithm. Each SCC with no incoming edges from outside the SCC is treated as a root SCC, and one representative node is picked as a root in the inverted display.
Summary by CodeRabbit
Bug Fixes
tree --invertso the tree no longer renders empty when cycles prevent clear root selection.Tests