# One command to catch 1000+ bug patterns (always master, cache-busted)
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" \
| bash -s --Just want it to do everything without confirmations? Live life on the edge with easy-mode to auto-install every dependency, accept all prompts, detect local coding agents, and wire their quality guardrails with zero extra questions:
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" \
| bash -s -- --easy-modeNote: Windows users must run the installer one-liner from within Git Bash, or use WSL for Windows.
You're coding faster than ever with Claude Code, Codex, Cursor, and other AI coding agents. You're shipping features in minutes that used to take days. But here's the painful truth:
JavaScript/TypeScript example (similar patterns exist in Python, Go, Rust, Java, C++, Ruby):
// β CRITICAL BUG #1: Null pointer crash waiting to happen
const submitButton = document.getElementById('submit');
submitButton.addEventListener('click', handleSubmit); // π₯ Crashes if element doesn't exist
// β CRITICAL BUG #2: XSS vulnerability
function displayUserComment(comment) {
document.getElementById('comments').innerHTML = comment; // π¨ Security hole
}
// β CRITICAL BUG #3: Silent failure (missing await)
async function saveUser(data) {
const result = validateUser(data); // π₯ Should be 'await validateUser(data)'
await saveToDatabase(result); // Saves undefined!
}
// β CRITICAL BUG #4: Always false comparison
if (calculatedValue === NaN) { // π₯ This NEVER works (always false)
console.log("Invalid calculation");
}
// β CRITICAL BUG #5: parseInt footgun
const zipCode = parseInt(userInput); // π₯ "08" becomes 0 in old browsers (octal!)Each of these bugs could cost 3-6 hours to debug in production. Similar issues plague every language: unguarded null access, missing await, security holes from eval(), buffer overflows from strcpy(), .unwrap() panics, goroutine leaks... You've probably hit all of them.
ubsauto-detects JavaScript/TypeScript, Python, C/C++, Rust, Go, Java, and Ruby in the same repo and fans out to per-language scanners.- Each scanner lives under
modules/ubs-<lang>.sh, ships independently, and supports--format text|json|jsonl|sariffor consistent downstream tooling. - Modules download lazily (PATH β repo
modules/β cached under${XDG_DATA_HOME:-$HOME/.local/share}/ubs/modules) and are validated before execution. - Results from every language merge into one text/JSON/SARIF report via
jq, so CI systems and AI agents only have to parse a single artifact.
- Every lazily-downloaded module ships with a pinned SHA-256 checksum baked into the meta-runner. Files fetched from GitHub are verified before they can execute, preventing tampering between releases.
- The cache lives under
${XDG_DATA_HOME:-$HOME/.local/share}/ubs/modulesby default; use--module-dirto relocate it (e.g., inside a CI workspace) while retaining the same verification guarantees. - Run
ubs doctorat any time to audit your environment. It checks for curl/wget availability, writable cache directories, and per-language module integrity. Add--fixto redownload missing or corrupted modules proactively. - Scanner runs still respect
--update-modules, but an invalid checksum now causes an immediate failure with remediation guidance rather than executing unverified code.
--category=resource-lifecyclefocuses the scanners on Python/Go/Java resource hygiene (context managers, defer symmetry, try-with-resources). UBS automatically narrows the language set to those with lifecycle packs enabled and suppresses unrelated categories.--comparison=<baseline.json>diff the latest combined summary against a stored run. Deltas feed into console output, JSON, HTML, and SARIF automation metadata so CI can detect regressions.--report-json=<file>writes an enriched summary (project, totals, git metadata, optional comparison block) that you can archive or share with teammates/CI.--html-report=<file>emits a standalone HTML preview showing totals, trends vs. baseline, and per-language breakdownsβideal for attaching to PRs or chat updates.- All shareable outputs inject GitHub permalinks when UBS is run inside a git repo with a GitHub remote. Text output automatically annotates
path:linereferences, JSON gainsgit.*metadata, and merged SARIF runs now includeversionControlProvenanceplusautomationDetailskeyed by the comparison id.
- Python β Category 16 now correlates every
open()call against matchingwith open(...)usage and explicitencoding=parameters, while Category 19 uses the new AST helper atmodules/helpers/resource_lifecycle_py.pyto walk every file, socket, subprocess, asyncio task, and context cancellation path. The helper resolves alias imports, context managers, and awaited tasks so the diff counts (acquire=X, release=Y, context-managed=Z) show the exact imbalance per file. - Go β Category 5/17 now run a Go AST walker (
modules/helpers/resource_lifecycle_go.go) that detectscontext.With*calls missing cancel,time.NewTicker/NewTimerwithoutStop,os.Open/sql.OpenwithoutClose, and mutexLock/Unlocksymmetry. Findings come straight from the AST positions, so βticker missing Stop()β lines map to the exactfile:lineinstead of coarse regex summaries. - Java β Category 5 surfaces
FileInputStream, readers/writers, JDBC handles, etc. that were created outside try-with-resources, while Category 19 keeps tracking executor services and file streams that never close. The new summary text matches the manifest fixtures, so CI will fail if regression swallows these warnings.
# 1) Capture a baseline JSON (checked into CI artifacts or local history)
ubs --ci --only=python --category=resource-lifecycle \
--report-json .ubs/baseline.json test-suite/python/buggy
# 2) Re-run with comparison + HTML preview for PRs or chat threads
ubs --ci --only=python --category=resource-lifecycle \
--comparison .ubs/baseline.json \
--report-json .ubs/latest.json \
--html-report .ubs/latest.html \
test-suite/python/buggylatest.json now contains the git metadata (repo URL, commit, blob_base) plus a comparison.delta block, and latest.html renders a lightweight dashboard summarising the deltas. SARIF uploads also pick up the comparison id so repeating runs in CI stay grouped by automation id.
# Scan current directory
ubs .
# Scan specific directory
ubs /path/to/your/project
# Verbose mode (show more code examples)
ubs -v .
# Save report to file
ubs . bug-report.txt
# CI mode (exit code 1 on warnings)
ubs . --fail-on-warning
# Quiet mode (summary only)
ubs -q .
# Skip specific categories (e.g., skip TODO markers)
ubs . --skip=11,14
# Custom file extensions
ubs . --include-ext=js,ts,vue,svelte# Git-aware quick scans (changed files only)
ubs --staged # Scan files staged for commit
ubs --diff # Scan working tree changes vs HEAD
# Strictness profiles
ubs --profile=strict # Fail on warnings, enforce high standards
ubs --profile=loose # Skip TODO/debug/code-quality nits when prototyping
# Machine-readable output
ubs . --format=json # Pure JSON on stdout; logs go to stderr
ubs . --format=jsonl # Line-delimited summary per scanner + totals
ubs . --format=jsonl --beads-jsonl out/findings.jsonl # Save JSONL for Beads/"strung"- UBS auto-ignores common junk (
node_modules, virtualenvs, dist/build/target/vendor, editor caches, etc.). - Inline suppression is available when a finding is intentional:
eval("print('safe')") # ubs:ignore
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" | bashexport UBS_MINISIGN_PUBKEY="RWQg+jMrKiloMT5L3URISMoRzCMc/pVcVRCTfuY+WIzttzIr4CUJYRUk"
curl -fsSL https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/scripts/verify.sh | bashThe verifier downloads SHA256SUMS + SHA256SUMS.minisig from the matching release, validates them with minisign, checks install.sh, and only then executes it. Use --insecure to bypass verification (not recommended).
Run directly (no install):
nix run github:Dicklesworthstone/ultimate_bug_scannerDev shell for contributors:
nix developPull & inspect:
docker run --rm ghcr.io/dicklesworthstone/ubs-tools ubs --helpScan host code (risk-aware: grants container access to host FS):
docker run --rm -v /:/host ghcr.io/dicklesworthstone/ubs-tools bash -c "cd /host/path && ubs ."- Release playbook (how we cut signed releases): docs/release.md
- Supply chain & verification model: docs/security.md
The installer will:
- β
Install the
ubscommand globally - β
Optionally install
ast-grep(for advanced AST analysis) - β
Optionally install
ripgrep(for 10x faster scanning) - β
Optionally install
jq(needed for JSON/SARIF merging across all language scanners) - β
Optionally install
typos(smart spellchecker for docs and identifiers) - β
Optionally install
Node.js + typescript(enables deep TypeScript type narrowing analysis) - β
Auto-run
ubs doctorpost-install and append a session summary to~/.config/ubs/session.md - β
Capture readiness facts (ripgrep/jq/typos/type narrowing) and store them for
ubs sessions --entries 1 - β Set up git hooks (block commits with critical bugs)
- β Set up Claude Code hooks (scan on file save)
- β Add documentation to your AGENTS.md
Need to revisit what the installer discovered later? Run ubs sessions --entries 1 to view the most recent session log (or point teammates at the same summary).
Need the βjust make it workβ button? Run the installer with --easy-mode to auto-install every dependency, accept all prompts, detect local coding agents, and wire their quality guardrails with zero extra questions:
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" \
| bash -s -- --easy-modeTotal time: 30 seconds to 2 minutes (depending on dependencies)
Need to keep your shell RC files untouched? Combine --no-path-modify (and optionally --skip-hooks) with the command aboveβthe installer will still drop ubs into your chosen --install-dir, but it will skip both PATH edits and the alias helper entirely.
# Download and install the unified runner
curl -fsSL https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/ubs \
-o /usr/local/bin/ubs && chmod +x /usr/local/bin/ubs
# Verify it works
ubs --help
# Optional but recommended: Install dependencies
npm install -g @ast-grep/cli # AST-based analysis
brew install ripgrep # 10x faster searching (or: apt/dnf/cargo install)
brew install typos-cli # Spellchecker tuned for code (or: cargo install typos-cli)
npm install -g typescript # Enables full tsserver-based type narrowing checks# Download once
curl -fsSL https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/ubs \
-o ubs && chmod +x ubs
# Run it
./ubs .Run the installer in --uninstall mode via curl if you want to remove UBS and all of its integrations:
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" | bash -s -- --uninstall --non-interactiveThis command deletes the UBS binary, shell RC snippets/aliases, config under ~/.config/ubs, and the optional Claude/Git hooks that the installer set up. Because it passes --non-interactive, it auto-confirms all prompts and runs unattended.
| Flag | What it does | Why it matters |
|---|---|---|
--dry-run |
Prints every install action (downloads, PATH edits, hook writes, cleanup) without touching disk. Dry runs still resolve config, detect agents, and show you exactly what would change. | Audit the installer, demo it to teammates, or validate CI steps without modifying a workstation. |
--self-test |
Immediately runs test-suite/install/run_tests.sh after installation and exits non-zero if the smoke suite fails. |
CI/CD jobs and verified setups can prove the installer still works end-to-end before trusting a release. |
--skip-type-narrowing |
Skip the Node.js + TypeScript readiness probe and the cross-language guard analyzers (JS/Rust/Kotlin/Swift). | Useful for air-gapped hosts or environments that want to stay in heuristic-only mode. |
--skip-typos |
Skip the Typos spellchecker installation + diagnostics. | Handy when corp images already provide Typos or when you deliberately disable spellcheck automation. |
--skip-doctor |
Skip the automatic ubs doctor run + session summary after install. |
Use when CI already runs doctor separately or when you're iterating locally and want a faster finish. |
Warning
--self-test requires running install.sh from a working tree that contains test-suite/install/run_tests.sh (i.e., the repo root). Curl-piping the installer from GitHub canβt self-test because the harness isnβt present, so the flag will error out early instead of giving a false sense of safety.
Note
After every install the script now double-checks command -v ubs. If another copy shadows the freshly written binary, youβll get an explicit warning with both paths so you can fix PATH order before running scans.
Tip
Type narrowing relies on Node.js plus the typescript npm package and the Python helpers that power the Rust/Kotlin/Swift checks. The installer now checks Node/TypeScript readiness, can optionally run npm install -g typescript, and surfaces the status inside install.sh --diagnose. Use --skip-type-narrowing if youβre on an air-gapped host or plan to keep the heuristic-only mode.
Tip
To avoid global npm permission issues, the installer now detects/installs bun just like other dependencies and uses bun install --global typescript by default, falling back to npm only if bun isnβt available.
The diagnostics also call out Swift guard readiness: if python3 is available we count .swift files under your repo and record whether the guard helper will actually run. That fact shows up in install.sh --diagnose output and the auto-generated session log so iOS/macOS teams can tell at a glance whether the ObjC-bridging heuristics are active.
Common combos
# Preview everything without touching dotfiles or hooks
bash install.sh --dry-run --no-path-modify --skip-hooks --non-interactive
# CI-friendly install that self-tests the smoke harness
bash install.sh --easy-mode --self-test --skip-hooksThe ubs meta-runner automatically checks for updates once every 24 hours. If a new version is available, it self-updates securely before running your scan.
To disable this behavior (e.g., in strict environments):
export UBS_NO_AUTO_UPDATE=1
# or
ubs --no-auto-update .Ultimate Bug Scanner is like having a senior developer review every line of code in under 5 seconds; it's the perfect automated companion to your favorite coding agent:
$ ubs .
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β π¬ ULTIMATE BUG SCANNER v4.4 - Scanning your project... β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
Project: /Users/you/awesome-app
Files: 247 JS/TS + 58 Python + 24 Go + 16 Java + 11 Ruby + 12 C++/Rust files
Finished: 3.2 seconds
βββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ
Summary Statistics:
Files scanned: 247
π₯ Critical: 0 β Would have crashed in production!
β οΈ Warnings: 8 β Should fix before shipping
βΉοΈ Info: 23 β Code quality improvements
β¨ EXCELLENT! No critical issues found β¨
18 specialized detection categories covering the bugs that actually matter:
| Category | What It Prevents | Time Saved Per Bug |
|---|---|---|
| Null Safety | "Cannot read property of undefined" crashes | 2-4 hours |
| Security Holes | XSS, code injection, prototype pollution | 8-20 hours + reputation damage |
| Async/Await Bugs | Race conditions, unhandled rejections | 4-8 hours |
| Memory Leaks | Event listeners, timers, detached DOM | 6-12 hours |
| Type Coercion | JavaScript's === vs == madness | 1-3 hours |
| + 13 more categories | 100+ hours/month saved | |
Small project (5K lines): 0.8 seconds β‘
Medium project (50K lines): 3.2 seconds π
Large project (200K lines): 12 seconds π¨
Huge project (1M lines): 58 seconds π
That's 10,000+ lines analyzed per second. Faster than you can say "but it worked on my machine."
Unlike traditional linters that fight AI-generated code, this scanner embraces it:
β
Designed for Claude Code, Cursor, Windsurf, Aider, Continue, Copilot
β
Zero configuration - works with ANY JS/TS, Python, C/C++, Rust, Go, Java, or Ruby project
β
Integrates with git hooks, CI/CD, file watchers
β
Actionable output (tells you WHAT's wrong and HOW to fix it)
β
Fails fast in CI (catch bugs before they merge)
β
React Hooks dependency analysis that spots missing deps, unstable objects, and stale closures
β
Lightweight taint analysis that traces req.body/window.location/localStorage β innerHTML/res.send/eval/exec/db.query and flags flows without DOMPurify/escapeHtml/parameterized SQL| Scenario | Without Scanner | With Scanner |
|---|---|---|
| AI implements user auth |
β’ 3 null pointer crashes (9h debugging) β’ 1 XSS vulnerability (8h + incident) β’ 2 race conditions (4h debugging) Total: ~21 hours + security incident |
β’ All issues caught in 4 seconds β’ Fixed before commit (15 min) Total: 15 minutes Savings: 84x faster β‘ |
| Refactor payment flow |
β’ Division by zero in edge case (3h) β’ Unhandled promise rejection (2h) β’ Missing error logging (1h) Total: 6 hours debugging |
β’ Caught instantly (3 sec) β’ Fixed before merge (10 min) Total: 10 minutes Savings: 36x faster π |
install.sh now inspects your workstation for the most common coding agents (the same set listed below) and, when asked, drops guardrails that remind those agents to run ubs --fail-on-warning . before claiming a task is done. In --easy-mode this happens automatically; otherwise you can approve each integration individually.
| Agent / IDE | What we wire up | Why it helps |
|---|---|---|
Claude Code Desktop (.claude/hooks/on-file-write.sh) |
File-save hook that shells out to ubs --ci whenever Claude saves JS/TS files. |
Keeps Claude from accepting βApply Patchβ without a fresh scan. |
Cursor (.cursor/rules) |
Shared rule block that tells Cursor plans/tasks to run ubs --fail-on-warning . and summarize outstanding issues. |
Cursorβs autonomous jobs inherit the same QA checklist as humans. |
Codex CLI (.codex/rules) |
Adds the identical rule block for Anthropicβs Codex terminal workflow. | Ensures Codex sessions never skip the scanner during long refactors. |
Gemini Code Assist (.gemini/rules) |
Guidance instructing Gemini agents to run ubs before closing a ticket. |
Keeps Geminiβs asynchronous fixes aligned with UBS exit criteria. |
Windsurf (.windsurf/rules) |
Guardrail text + sample command palette snippet referencing ubs. |
Windsurfβs multi-step plans stay grounded in the same quality gate. |
Cline (.cline/rules) |
Markdown instructions that Clineβs VS Code extension ingests. | Forces every βtool callβ from Cline to mention scanner findings. |
OpenCode MCP (.opencode/rules) |
Local MCP instructions so HTTP tooling always calls ubs before replying. |
Makes OpenCodeβs multi-agent swarms share the same notion of βdoneβ. |
When you're coding with AI, you're moving 10-100x faster than traditional development. But bugs accumulate just as quickly. Traditional tools slow you down. This scanner keeps pace:
Traditional workflow: AI-powered workflow with scanner:
ββββββββββββββββββββ ββββββββββββββββββββ
β AI writes code β β AI writes code β
ββββββββββ¬ββββββββββ ββββββββββ¬ββββββββββ
β β
β β
ββββββββββββββββββββ ββββββββββββββββββββ
β You review β β Scanner runs β
β (15 min) β β (3 seconds) β
ββββββββββ¬ββββββββββ ββββββββββ¬ββββββββββ
β β
β β
ββββββββββββββββββββ ββββββββββββββββββββ
β Tests pass? β β Critical bugs? β
ββββββββββ¬ββββββββββ ββββββββββ¬ββββββββββ
β NO! β YES!
β β
ββββββββββββββββββββ ββββββββββββββββββββ
β Debug in prod β β AI fixes them β
β (6 hours) β β (5 minutes) β
ββββββββββββββββββββ ββββββββββ¬ββββββββββ
β
ββββββββββββββββββββ
β Ship with β
β confidence β
ββββββββββββββββββββ
Total: 6.25 hours Total: 8 minutes
Drop this into .claude/hooks/on-file-write.sh:
#!/bin/bash
# Auto-scan UBS-supported languages (JS/TS, Python, C/C++, Rust, Go, Java, Ruby) on save
if [[ "$FILE_PATH" =~ \.(js|jsx|ts|tsx|mjs|cjs|py|pyw|pyi|c|cc|cpp|cxx|h|hh|hpp|hxx|rs|go|java|rb)$ ]]; then
echo "π¬ Quality check running..."
if ubs "${PROJECT_DIR}" --ci 2>&1 | head -30; then
echo "β
No critical issues"
else
echo "β οΈ Issues detected - review above"
fi
fiResult: Every time Claude writes code, the scanner catches bugs instantly.
The installer can set this up automatically, or add to .git/hooks/pre-commit:
#!/bin/bash
# Block commits with critical bugs
echo "π¬ Running bug scanner..."
if ! ubs . --fail-on-warning 2>&1 | tee /tmp/scan.txt | tail -30; then
echo ""
echo "β Critical issues found. Fix them or use: git commit --no-verify"
echo ""
echo "Top issues:"
grep -A 3 "π₯ CRITICAL" /tmp/scan.txt | head -20
exit 1
fi
echo "β
Quality check passed - committing..."Result: Bugs cannot be committed. Period.
Add to your .cursorrules or similar:
## Code Quality Standards
Before marking any task as complete:
1. Run the bug scanner: `ubs .`
2. Fix ALL critical issues (π₯)
3. Review warnings (β οΈ) and fix if trivial
4. Only then mark task complete
If the scanner finds critical issues, your task is NOT done.Result: AI agents have built-in quality standards.
name: Code Quality Gate
on: [push, pull_request]
jobs:
bug-scan:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Install Bug Scanner
run: |
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" | bash -s -- --non-interactive
- name: Scan for Bugs
run: |
ubs . --fail-on-warning --ciResult: Pull requests with critical bugs cannot merge.
This is the golden pattern for AI coding workflows:
#!/bin/bash
# Have your AI agent run this after implementing features
echo "π¬ Post-implementation quality check..."
# Run scanner
if ubs . --fail-on-warning > /tmp/scan-result.txt 2>&1; then
echo "β
All quality checks passed!"
echo "π Ready to commit"
exit 0
else
echo "β Issues found:"
echo ""
# Show critical issues
grep -A 5 "π₯ CRITICAL" /tmp/scan-result.txt | head -30
echo ""
echo "π€ AI: Please fix these issues and re-run this check"
exit 1
fiUsage pattern:
User: "Add user registration with email validation"
AI Agent:
1. Implements the feature
2. Runs quality check (scanner finds 3 critical bugs)
3. Fixes the bugs
4. Re-runs quality check (passes)
5. Commits the code
Total time: 12 minutes (vs. 6 hours debugging in production)Train your AI agent to use this decision tree:
Did I modify code in any supported language?
(JS/TS, Python, Go, Rust, Java, C++, Ruby)
β
β YES
Changed more than 50 lines?
β
β YES
Run scanner ββββββββββββ
β β
β β
Critical issues found? βββββ€ YES
β NO β
β β
Warnings? β
β β
β YES β
Show to user β
Ask if should fix ββββββββ€
β NO β
β β
Commit code Fix issues
Important
Copy the blurb below to your project's AGENTS.md, .claude/claude_docs/, or .cursorrules file for comprehensive UBS integration guidance.
## UBS Quick Reference for AI Agents
UBS stands for "Ultimate Bug Scanner": **The AI Coding Agent's Secret Weapon: Flagging Likely Bugs for Fixing Early On**
**Install:** `curl -sSL https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/main/install.sh | bash`
**Golden Rule:** `ubs <changed-files>` before every commit. Exit 0 = safe. Exit >0 = fix & re-run.
**Commands:**
```bash
ubs file.ts file2.py # Specific files (< 1s) β USE THIS
ubs $(git diff --name-only --cached) # Staged files β before commit
ubs --only=js,python src/ # Language filter (3-5x faster)
ubs --ci --fail-on-warning . # CI mode β before PR
ubs --help # Full command reference
ubs sessions --entries 1 # Tail the latest install session log
ubs . # Whole project (ignores things like .venv and node_modules automatically)
```
**Output Format:**
```
β οΈ Category (N errors)
file.ts:42:5 β Issue description
π‘ Suggested fix
Exit code: 1
```
Parse: `file:line:col` β location | π‘ β how to fix | Exit 0/1 β pass/fail
**Fix Workflow:**
1. Read finding β category + fix suggestion
2. Navigate `file:line:col` β view context
3. Verify real issue (not false positive)
4. Fix root cause (not symptom)
5. Re-run `ubs <file>` β exit 0
6. Commit
**Speed Critical:** Scope to changed files. `ubs src/file.ts` (< 1s) vs `ubs .` (30s). Never full scan for small edits.
**Bug Severity:**
- **Critical** (always fix): Null safety, XSS/injection, async/await, memory leaks
- **Important** (production): Type narrowing, division-by-zero, resource leaks
- **Contextual** (judgment): TODO/FIXME, console logs
**Anti-Patterns:**
- β Ignore findings β β
Investigate each
- β Full scan per edit β β
Scope to file
- β Fix symptom (`if (x) { x.y }`) β β
Root cause (`x?.y`)Examples show JavaScript output; each language has equivalent detections (Python: None checks, Go: nil guards, Rust: Option handling, etc.)
$ ubs src/
βββ NULL SAFETY & DEFENSIVE PROGRAMMING
Detects: Null pointer dereferences, missing guards, unsafe property access
π₯ CRITICAL (5 found)
Unguarded property access after getElementById
Consider: const el = document.getElementById('x'); if (!el) return;
src/components/form.js:42
const submitBtn = document.getElementById('submit-button');
submitBtn.classList.add('active'); // β Crashes if element missing
src/utils/dom.js:87
const modal = document.querySelector('.modal');
modal.style.display = 'block'; // β Runtime crash guaranteed
π‘ Fix: Always check for null before accessing propertiesBefore: 3 production crashes this week After: 0 crashes, caught in 2 seconds
βββ SECURITY VULNERABILITIES
Detects: Code injection, XSS, prototype pollution, timing attacks
π₯ CRITICAL (3 found)
innerHTML without sanitization - XSS risk
Use textContent or DOMPurify.sanitize()
src/comments.js:156
element.innerHTML = userComment; // β XSS vulnerability!
π₯ CRITICAL (1 found)
Hardcoded API keys detected
Use environment variables or secret managers
src/config.js:23
const apiKey = "sk_live_abc123xyz"; // β Security breach!Before: Security incident, customer data at risk After: Vulnerability caught before git commit
βββ ASYNC/AWAIT & PROMISE PITFALLS
Detects: Missing await, unhandled rejections, race conditions
π₯ CRITICAL (8 found)
await used in non-async function
SyntaxError in JavaScript
src/api/users.js:67
function saveUser(data) {
await database.insert(data); // β SyntaxError!
}
β οΈ WARNING (12 found)
Promises without .catch() or try/catch
Unhandled rejections crash Node.js
src/services/email.js:45
sendEmail(user.email).then(result => ...) // β No error handling!Before: Silent failures, mysterious bugs in production After: All async bugs caught and fixed before deploy
Each language module has specialized detections. Examples below are representative (JavaScript shown; Python has eval(), Go has goroutine leaks, Rust has .unwrap() panics, C++ has buffer overflows, etc.)
These WILL cause crashes, security breaches, or data corruption:
| Pattern | Example | Why It's Dangerous |
|---|---|---|
eval() usage |
eval(userInput) |
Allows arbitrary code execution - RCE vulnerability |
| Direct NaN comparison | if (x === NaN) |
Always returns false - logic bug |
| Missing await | asyncFunc() in async context |
Silent failures, race conditions - data corruption |
| Prototype pollution | obj.__proto__ = {} |
Security vulnerability - privilege escalation |
| Unguarded null access | el.style.color without null check |
Runtime crash guaranteed |
parseInt without radix |
parseInt("08") |
Returns 0 in some browsers - calculation bug |
| Empty catch blocks | catch(e) {} |
Swallows errors - debugging nightmare |
innerHTML with user data |
el.innerHTML = userInput |
XSS vulnerability |
| Missing async keyword | await without async function |
SyntaxError |
| Hardcoded secrets | const key = "sk_live..." |
Security breach |
These cause bugs, performance issues, or maintenance headaches:
| Pattern | Example | Impact |
|---|---|---|
Promises without .catch() |
promise.then(...) |
Unhandled rejections crash Node.js |
| Division without zero check | total / count |
Returns Infinity or NaN |
| Event listeners without cleanup | addEventListener in React |
Memory leak (app gets slower over time) |
setInterval without clear |
setInterval(fn, 1000) |
Timer leak (infinite timers) |
await inside loops |
for(...) { await api.call() } |
Slow (sequential, not parallel) |
| Array mutation during iteration | arr.forEach(() => arr.push(...)) |
Skipped/duplicate elements |
| Missing switch default | switch(x) { case 1: ... } |
Unhandled values cause silent failures |
isNaN() instead of Number.isNaN() |
isNaN("foo") |
Type coercion bugs |
Improvements that make code cleaner and more maintainable:
- Optional chaining opportunities (
obj?.prop?.value) - Nullish coalescing opportunities (
value ?? default) - TypeScript
anyusage (reduces type safety) console.logstatements (remove before production)- Technical debt markers (TODO, FIXME, HACK)
- Performance optimizations (DOM queries in loops)
varusage (uselet/constinstead)- Deep property access without guards
- Large inline arrays (move to separate files)
- Complex nested ternaries (readability)
ubs [OPTIONS] [PROJECT_DIR] [OUTPUT_FILE]
Core Options:
-v, --verbose Show 10 code samples per finding (default: 3)
-q, --quiet Minimal output (summary only)
--ci CI mode (stable output, no colors by default)
--fail-on-warning Exit with code 1 on warnings (strict mode)
--version Print UBS meta-runner version and exit
--profile=MODE strict|loose (sets defaults for strictness)
--baseline=FILE Compare findings against a baseline JSON (alias for --comparison)
-h, --help Show help and exit
Git Integration:
--staged Scan only files staged for commit
--diff, --git-diff Scan only modified files (working tree vs HEAD)
Output Control:
--format=FMT Output format: text|json|jsonl|sarif (default: text)
--beads-jsonl=FILE Write JSONL summary alongside normal output for Beads/"strung"
--no-color Force disable ANSI colors
OUTPUT_FILE Save report to file (auto-tees to stdout)
File Selection:
--include-ext=CSV File extensions (default: auto-detect by language)
JS: js,jsx,ts,tsx,mjs,cjs | Python: py,pyi,pyx
Go: go | Rust: rs | Java: java | C++: cpp,cc,cxx,c,h
Ruby: rb,rake,ru | Custom: --include-ext=js,ts,vue
--exclude=GLOB[,...] Additional paths to exclude (comma-separated)
Example: --exclude=legacy (deps ignored by default)
Performance:
--jobs=N Parallel jobs for ripgrep (default: auto-detect cores)
Set to 1 for deterministic output
Rule Control:
--skip=CSV Skip categories by number (see output for numbers)
Example: --skip=11,14 # Skip debug code + TODOs
--skip-type-narrowing Disable tsserver-based guard analysis (falls back to text heuristics)
--rules=DIR Additional ast-grep rules directory
Rules are merged with built-in rules
--no-auto-update Disable automatic self-update
--suggest-ignore Print large-directory candidates to add to .ubsignore (no changes applied)
Environment Variables:
JOBS Same as --jobs=N
NO_COLOR Disable colors (respects standard)
CI Enable CI mode automatically
Arguments:
PROJECT_DIR Directory to scan (default: current directory)
OUTPUT_FILE Save full report to file
Exit Codes:
0 No critical issues (or no issues at all)
1 Critical issues found
1 Warnings found (only with --fail-on-warning)
2 Invalid arguments or configuration# Basic scan
ubs .
# Verbose scan with full details
ubs -v /path/to/project
# Strict mode for CI (fail on any warning)
ubs --fail-on-warning --ci
# Save report without cluttering terminal
ubs . report.txt
# Scan Vue.js project
ubs . --include-ext=js,ts,vue
# Skip categories you don't care about
ubs . --skip=14 # Skip TODO/FIXME markers
# Maximum performance (use all cores)
ubs --jobs=0 . # Auto-detect
ubs --jobs=16 . # Explicit core count
# Exclude vendor code
ubs . --exclude=node_modules,vendor,dist,build
# Custom rules directory
ubs . --rules=~/.config/ubs/custom-rules
# Combine multiple options
ubs -v --fail-on-warning --exclude=legacy --include-ext=js,ts,tsx . report.txt--format=jsonl (and --beads-jsonl=FILE) emit newline-delimited objects for easy piping into tools like Beads or jq:
{"type":"scanner","project":"/path/to/project","language":"python","files":42,"critical":1,"warning":3,"info":12,"timestamp":"2025-11-22T09:04:20Z"}
{"type":"totals","project":"/path/to/project","files":99,"critical":1,"warning":3,"info":27,"timestamp":"2025-11-22T09:04:22Z"}You can add your own bug detection patterns:
# Create custom rules directory
mkdir -p ~/.config/ubs/rules
# Add a custom rule (YAML format)
cat > ~/.config/ubs/rules/no-console-in-prod.yml <<'EOF'
id: custom.no-console-in-prod
language: javascript
rule:
any:
- pattern: console.log($$$)
- pattern: console.debug($$$)
- pattern: console.info($$$)
severity: warning
message: "console statements should be removed before production"
note: "Use a proper logging library or remove debug statements"
EOF
# Run with custom rules
ubs . --rules=~/.config/ubs/rulesCommon custom rules:
# Enforce specific naming conventions
id: custom.component-naming
language: typescript
rule:
pattern: export function $NAME() { $$$ }
not:
pattern: export function $UPPER() { $$$ }
severity: info
message: "React components should start with uppercase letter"# Catch specific anti-patterns in your codebase
id: custom.no-direct-state-mutation
language: typescript
rule:
pattern: this.state.$FIELD = $VALUE
severity: critical
message: "Never mutate state directly - use setState()"If the scanner reports false positives for your specific use case:
# Skip entire categories
ubs . --skip=11,14 # Skip debug code detection and TODO markers
# Exclude specific files/directories
ubs . --exclude=legacy,third-party,generated
# For persistent config, create a wrapper script
cat > ~/bin/ubs-custom <<'EOF'
#!/bin/bash
ubs "$@" \
--exclude=legacy,generated \
--skip=14 \
--rules=~/.config/ubs/rules
EOF
chmod +x ~/bin/ubs-customThe scanner uses a sophisticated 4-layer approach:
Layer 1: PATTERN MATCHING (Fast) βββ
ββ Regex-based detection β
ββ Optimized with ripgrep β
ββ Finds 70% of bugs in <1 second β
ββββΊ Combined Results
Layer 2: AST ANALYSIS (Deep) βββββββ€
ββ Semantic code understanding β
ββ Powered by ast-grep β
ββ Catches complex patterns β
β
Layer 3: CONTEXT AWARENESS (Smart) β€
ββ Understands surrounding code β
ββ Reduces false positives β
ββ Knows when rules don't apply β
β
Layer 4: STATISTICAL (Insightful) β
ββ Code smell detection β
ββ Anomaly identification β
ββ Architectural suggestions β
β
Final Report (3-5 sec)
| Component | Technology | Purpose | Why This Choice |
|---|---|---|---|
| Core Engine | Bash 4.0+ | Orchestration | Universal compatibility, zero dependencies |
| Pattern Matching | Ripgrep | Text search | 10-100x faster than grep, parallelized |
| AST Parser | ast-grep | Semantic analysis | Understands code structure, not just text |
| Fallback | GNU grep | Text search | Works on any Unix-like system |
| Rule Engine | YAML | Pattern definitions | Human-readable, easy to extend |
# Automatic parallelization (uses all CPU cores)
- Auto-detects: 16-core = 16 parallel jobs
- Manually set: --jobs=N
# Smart file filtering (only scans relevant files)
- JS/TS: .js, .jsx, .ts, .tsx, .mjs, .cjs (auto-skip node_modules/dist/build)
- Python: .py + pyproject/requirements (skip venv/__pycache__)
- C/C++: .c/.cc/.cpp/.cxx + headers + CMake files (skip build/out)
- Rust: .rs + Cargo manifests (skip target/.cargo)
- Go: .go + go.mod/go.sum/go.work (skip vendor/bin)
- Java: .java + pom.xml + Gradle scripts (skip target/build/out)
- Ruby: .rb + Gemfile/Gemspec/Rakefile (skip vendor/bundle,tmp)
- Custom: --include-ext=js,ts,vue
# Efficient streaming (low memory usage)
- No temp files created
- Results streamed as found
- Memory usage: <100MB for most projects
# Incremental scanning (future feature)
- Only scan changed files (git diff)
- Cache previous results
- 10x faster on large projects| Feature | Ultimate Bug Scanner | ESLint | TypeScript | SonarQube | DeepCode |
|---|---|---|---|---|---|
| Setup Time | 30 seconds | 30 minutes | 1-2 hours | 2-4 hours | Account required |
| Speed (50K lines) | 3 seconds | 15 seconds | 8 seconds | 2 minutes | Cloud upload |
| Zero Config | β Yes | β No | β No | β No | β No |
| Works Without Types | β Yes | β Yes | β No | β Yes | β Yes |
| Null Safety | β Yes | β Yes | |||
| Security Scanning | β Yes | β No | β Yes | β Yes | |
| Memory Leaks | β Yes | β No | β No | β No | |
| Async/Await | β Deep | β Good | |||
| CI/CD Ready | β Yes | β Yes | β Yes | β Yes | |
| Offline | β Yes | β Yes | β Yes | β No | |
| AI Agent Friendly | β Built for it | β Complex | |||
| Cost | Free | Free | Free | $$$$ | $$$ |
When to use what:
- Ultimate Bug Scanner: Quick scans, AI workflows, no config needed
- ESLint: Style enforcement, custom rules, team standards
- TypeScript: Type safety (use WITH this scanner)
- SonarQube: Enterprise compliance, detailed metrics
- DeepCode: ML-powered analysis (if you trust cloud)
Best combo: TypeScript + ESLint + Ultimate Bug Scanner = Maximum safety
You might be thinking: "We already have ESLint, Pylint, Clippy, RuboCop... why build another tool?"
Fair question. And honestly, your first reaction is probably right to be skeptical.
When you first look at UBS, it's natural to think:
"This is just worse ESLint. It has fewer rules, uses regex (false positives!), and doesn't auto-fix anything. Why would I use this instead of mature, comprehensive linters?"
That's analyzing through the wrong lens.
You're comparing it to tools designed for a fundamentally different workflow (human developers writing code manually) when it's solving a fundamentally different problem (LLM agents generating code at 100x speed).
It's like comparing a smoke detector to a building inspector:
- Building inspector (ESLint): Thorough, comprehensive, finds every issue, takes hours
- Smoke detector (UBS): Fast, catches critical dangers, instant alert, always running
You need both. But when your house might be on fire (AI just generated 500 lines in 30 seconds), you want the smoke detector first.
Software development is undergoing a fundamental transformation:
2020 (Pre-LLM Era):
- Developer writes 50-200 lines/day manually
- Deep thought before each line
- Single language per project (mostly)
- Time to review: abundant
- Quality gate: comprehensive linting + code review (hours)
2025 (LLM Era):
- AI generates 500-5000 lines/day across projects
- Code appears in seconds
- Polyglot projects standard (microservices in Go, UI in TypeScript, ML in Python, workers in Rust)
- Time to review: scarce
- Quality gate needed: instant feedback (<5s) or the loop breaks
Traditional tools weren't designed for this. They were built when "code generation" meant 200 lines/day, not 2000.
Traditional linters were designed for human developers in single-language codebases. UBS is designed for LLM coding agents working across polyglot projects.
The paradigm shift:
| Traditional Linting (Human-First) | UBS Approach (LLM-First) |
|---|---|
| Goal: Comprehensive coverage + auto-fix Speed: 15-60 seconds acceptable Setup: 30 min config per language Languages: One tool per language False positives: Must be <1% (frustrates humans) Output: Human-readable prose |
Goal: Critical bug detection + fast feedback Speed: <5 seconds required Setup: Zero config (instant start) Languages: One scan for all 7 languages False positives: 10-20% OK (LLMs filter instantly) Output: Structured file:line for LLM parsing |
Why traditional linters have auto-fix:
// ESLint flags: "Use === instead of =="
if (value == null) // β
// ESLint auto-fix (rigid, no context):
if (value === null) // β
Technically correct, but...Why UBS doesn't (and shouldn't):
// UBS flags: "Type coercion bug: == should be ==="
if (value == null) // β
// Claude reads the error and understands context:
if (value !== null && value !== undefined) // β
Better - handles both
// OR
if (value != null) // β
Or keeps == for null/undefined (intentional)The hard part is DETECTION, not fixing. Once flagged, LLMs can:
- Understand semantic context
- Consider surrounding code
- Apply the right fix (not just the mechanical one)
- Refactor holistically
Auto-fix would be worse because it's context-free. LLMs need to know WHAT'S wrong and WHERE, then they fix it properly.
Imagine asking Claude to set up quality gates for a polyglot project:
Traditional approach (15-30 min per project):
# JavaScript/TypeScript
npm install --save-dev eslint @eslint/js @typescript-eslint/parser
# Create .eslintrc.js (200 lines of config)
# Python
pip install pylint black mypy
# Create .pylintrc, pyproject.toml sections
# Rust
# Add to Cargo.toml: [lints]
# Configure clippy rules
# Go
# Install golangci-lint, create .golangci.yml
# Java
# Setup Checkstyle + PMD + SpotBugs + config XMLs
# C++
# Setup clang-tidy, create .clang-tidy config
# Ruby
# Create .rubocop.yml with 150+ lines
# Now run 7 different commands and parse 7 different output formats...UBS approach (30 seconds):
curl -fsSL https://raw.githubusercontent.com/.../install.sh | bash
ubs .
# Done. All 7 languages scanned, unified report.This matters because:
- LLMs generate code across languages in one session (Python API β Go service β TypeScript UI β Rust worker)
- Configuring 7 tools is error-prone for LLMs
- Humans don't want to maintain 7 different config files
- CI/CD pipelines want one command, one exit code
- TypeScript β UBS shells out to
tsserver(via the bundled helper) whenever Node.js + thetypescriptpackage are available. The installer surfaces a "Type narrowing readiness" diagnostic so you immediately know if tsserver-powered guards are running. - Rust β A Python helper inspects
if let Some/Okguard clauses and flags subsequent.unwrap()/.expect()calls outside of exiting blocks. Fixtures and manifest cases keep this regression-tested. - Kotlin β The Java module scans
.ktsources forif (value == null)guards that merely log and keep running before hittingvalue!!, catching the same pitfall on JVM teams that mix Java + Kotlin. - Swift β The dedicated
ubs-swiftmodule now ships the guard-lethelper directly, so optional chaining/ObjectiveβC bridging heuristics fire even when you runubs --only=swiftlocally (no piggybacking on the Java module). It catches cases where code logs and keeps going before force-unwrappingvalue!, protecting iOS/macOS pipelines that blend Swift + ObjC.
- Python β
modules/helpers/resource_lifecycle_py.pynow reasons over the AST, trackingwith/async with, alias imports, and.open()/.connect()calls soubs-pythonwarns only when a handle is truly leaking. PathlibPath.open()and similar patterns are handled without brittle regexes. - Java β New ast-grep rules (
java.resource.executor-no-shutdown,java.resource.thread-no-join,java.resource.jdbc-no-close,java.resource.resultset-no-close,java.resource.statement-no-close) ensure ExecutorServices, rawThreads,java.sql.Connections,Statement/PreparedStatement/CallableStatement, andResultSethandles all get proper shutdown/close semantics before the regex fallback ever runs. - C++ / Rust / Ruby β These modules already relied on ast-grep rule packs; the βUniversal AST Adoptionβ epic is now complete with every language module (JS, Python, Go, C++, Rust, Java, Ruby, Swift, Kotlin) running semantic detectors instead of fragile grep-only heuristics.
import asyncio, subprocess
fh = open("/tmp/leaky.txt", "w")
proc = subprocess.Popen(["sleep", "1"])
async def leak_task():
task = asyncio.create_task(asyncio.sleep(1))
await asyncio.sleep(0.1)
return task
asyncio.run(leak_task())$ ./ubs --only=python test-suite/python/buggy/resource_lifecycle.py
π₯ File handles opened without context manager/close [resource_lifecycle.py:4]
File handle fh opened without context manager or close()
β Popen handles not waited or terminated [resource_lifecycle.py:7]
The helper catches the unguarded file handle, zombie subprocess, and orphaned asyncio task because it walks the AST (tracking aliases and async contexts) instead of grepping for strings.
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
ticker := time.NewTicker(time.Millisecond * 500)
timer := time.NewTimer(time.Second)
f, _ := os.Open("/tmp/data.txt")
_ = ctx
_ = cancel
_ = ticker
_ = timer
_ = f$ ./ubs --only=golang test-suite/golang/buggy/resource_lifecycle.go
π₯ context.With* without deferred cancel [resource_lifecycle.go:10]
β time.NewTicker not stopped [resource_lifecycle.go:13]
β time.NewTimer not stopped [resource_lifecycle.go:15]
β os.Open/OpenFile without defer Close() [resource_lifecycle.go:17]
Because the helper hashes AST positions, the manifest can assert on deterministic substrings (context/ticker/timer/file) and we avoid flakiness from color codes or log headings.
Use --skip-type-narrowing (or UBS_SKIP_TYPE_NARROWING=1) when you want to bypass all of these guard analyzersβfor example on air-gapped CI environments or when validating legacy projects one language at a time.
The generate β scan β fix cycle needs to be fast for AI workflows:
βββββββββββββββββββββββββββββββββββββββββββ
β Traditional Linter (30-45 seconds) β
βββββββββββββββββββββββββββββββββββββββββββ€
β Claude generates code: 10s β
β Run ESLint + Pylint + ... 30s β³ β
β Claude reads findings: 5s β
β Claude fixes bugs: 15s β
β Re-run linters: 30s β³ β
β ββββββββββββββββββββββββββββββββββ β
β Total iteration: 90s β
βββββββββββββββββββββββββββββββββββββββββββ
βββββββββββββββββββββββββββββββββββββββββββ
β UBS (3-5 seconds) β
βββββββββββββββββββββββββββββββββββββββββββ€
β Claude generates code: 10s β
β Run UBS: 3s β‘ β
β Claude reads findings: 2s β
β Claude fixes bugs: 10s β
β Re-run UBS: 3s β‘ β
β ββββββββββββββββββββββββββββββββββ β
β Total iteration: 28s β
βββββββββββββββββββββββββββββββββββββββββββ
3x faster feedback loop = 3x more iterations in the same time
When you're shipping 10+ features a day with AI assistance, this compounds.
UBS targets the bugs AI agents actually generate, not every possible code smell.
Bugs LLMs frequently produce:
| Pattern | Why LLMs Generate It | Traditional Linters |
|---|---|---|
Missing await |
Forgets async keyword, syntax looks fine |
β TypeScript only |
| Unguarded null access | "Optimistic" coding - assumes happy path | |
eval() / code injection |
Reaches for "easy" dynamic solution | β Most flag this |
| Memory leaks (event listeners) | Doesn't think about cleanup lifecycle | β ESLint plugin needed |
innerHTML XSS |
Doesn't threat-model user input | |
| Division by zero | Doesn't consider edge cases | β Most miss this |
| Hardcoded secrets | Uses placeholder, forgets to externalize | |
| Goroutine leaks | Forgets context cancellation | β Go-specific tooling |
.unwrap() panics |
Assumes success path | β Clippy catches |
| Buffer overflows | Forgets bounds checking |
UBS is optimized for this specific threat model.
This is genuinely not available in standard linters:
# Code LLM generates:
def get_theme(user):
return user.profile.settings.theme # β Unguarded chain
# ESLint/Pylint: β
No error (syntactically correct)
# TypeScript: β
No error (if types claim non-null)
# UBS Deep Guard Analysis:
# 1. Scans for: user.profile.settings.theme (found at line 42)
# 2. Scans for: if user and user.profile and user.profile.settings
# 3. Correlates: NO MATCHING GUARD FOUND
# 4. Reports: β οΈ Unguarded deep property accessThis requires:
- AST extraction of property chains across the file
- AST extraction of conditional guards
- Cross-reference matching with context awareness
- Contextual suggestions
Nobody else does this by default because it's not a lint ruleβit's a correlation analysis across multiple code patterns.
UBS is designed to work WITH existing tools, not replace them:
ββββββββββββββββββββββββββββββββββββββββββββββββββββββ
β Your Quality Stack (Recommended) β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββ€
β TypeScript β Type safety β
β ESLint/Clippy/etc β Comprehensive linting β
β Jest/PyTest β Unit tests β
β β¨ UBS β AI-generated bug oracle β
β GitHub Actions β CI/CD integration β
ββββββββββββββββββββββββββββββββββββββββββββββββββββββ
Use UBS for:
- β Fast multi-language scanning in AI workflows
- β Critical bug detection before commits
- β Git hooks that block obviously broken code
- β Claude/Cursor/AI agent quality guardrails
- β Polyglot projects where configuring 7 linters is painful
Use ESLint/Pylint/Clippy/etc for:
- β Comprehensive style enforcement
- β Framework-specific rules (React hooks, etc.)
- β Custom team conventions
- β Auto-formatting
- β Deep single-language analysis
They solve different problems. UBS is the "smoke detector" (fast, catches critical issues). Traditional linters are the "building inspector" (thorough, catches everything).
What makes this hard to replicate:
Multi-layer analysis:
Layer 1: Ripgrep (regex) β 70% of bugs in 0.5s
Layer 2: ast-grep (AST) β Complex semantic patterns
Layer 3: Correlation logic β Cross-pattern analysis (novel)
Layer 4: Metrics collection β Time-series quality tracking
This combination of speed + semantic understanding + correlation is unique.
Unified multi-language runner:
- Auto-detects 7 languages in one scan
- Parallel execution (Go + Python + Rust simultaneously)
- Unified JSON/SARIF output for tooling
- Module system with lazy download/caching
LLM-optimized integration points:
- Git hooks (block bad commits)
- Claude Code file-write hooks
.cursorrules/.aiconfigintegration- Clean structured output for LLM parsing
You might notice: ESLint has 200+ core rules, Clippy has 600+ lints, but UBS has ~30 patterns per language.
That's intentional, not a limitation.
The 80/20 rule for AI-generated bugs:
- 80% of production-breaking bugs come from ~30 common patterns
- 20% of edge cases require the other 570 rules
For LLM workflows, you want:
β
Fast scan (3s) that catches 80% of critical bugs
β
LLM fixes them immediately
β
β
Fast re-scan (3s) confirms fixes
β
Then run comprehensive linters (30s) for the remaining 20%
Not:
β Comprehensive scan (30s) that catches 100% of issues
β
LLM waits... workflow broken... context switch...
β
Slower iteration = fewer features shipped
The bugs UBS targets are:
- Missing
await(crashes) - Null pointer access (crashes)
- Security holes:
eval(), XSS, hardcoded secrets (breaches) - Memory leaks (performance degradation)
- Race conditions (data corruption)
The bugs comprehensive linters add:
- Inconsistent quote style (style)
- Missing trailing commas (style)
- Prefer
constoverletwhen not reassigned (style) - Function name should be camelCase (style)
- Line too long (style)
Which matters more when AI just generated 500 lines that might have eval() and missing await everywhere?
Target the critical bugs that cost hours. Let comprehensive linters handle style in a separate pass.
Why this tool exists NOW:
2021:
- GitHub Copilot launches (single-line completions)
- Still mostly human-written code
- Traditional linting workflow works fine
2023:
- ChatGPT/GPT-4 can generate full functions
- Claude Code, Cursor emerge
- Devs start AI-assisted workflows
- Pain point appears: "AI is fast but buggy"
2025:
- LLMs generate entire features in minutes
- Multi-file refactors happen in seconds
- Polyglot microservices are standard
- Quality gates can't keep up with generation speed
The problem UBS solves didn't exist before LLM coding became mainstream.
This tool is perfectly timed for the AI coding explosion happening RIGHT NOW.
For human developers:
- False positive = context switch + investigation + frustration
- Acceptable rate: <1%
For LLM agents:
- False positive = parse (0.1s) + analyze (0.5s) + determine safe (0.2s)
- Acceptable rate: 10-20%
LLMs don't get frustrated. They evaluate every finding programmatically.
This means UBS can be more aggressive:
- Flag suspicious patterns even if not 100% certain
- Catch more bugs at the cost of some noise
- LLMs filter false positives cognitively (for free)
Better to flag 100 issues where 20 are safe than miss 1 critical bug.
A: It's not reinventing the wheelβit's building a different vehicle for a different road.
ESLint is a truck (heavy, comprehensive, hauls everything). UBS is a sports car (fast, targeted, gets you there quickly).
You wouldn't use a truck for a Formula 1 race. You wouldn't use a sports car to move furniture.
Different tools, different use cases. Use UBS for rapid AI iteration, ESLint for comprehensive quality enforcement.
A: Three reasons:
1. Different design philosophy
- Existing linters: comprehensive, human-first, single-language
- UBS: fast, LLM-first, multi-language, correlation-based
These are fundamentally incompatible goals. ESLint would never accept "10-20% false positives are fine" or "skip auto-fix entirely."
2. Multi-language meta-runner
- The unified runner that auto-detects 7 languages is the core innovation
- This doesn't fit into any single linter's architecture
- Each linter project has different maintainers, philosophies, release cycles
3. Correlation analysis is novel
- Deep property guard matching isn't a "lint rule"
- It's cross-pattern analysis that requires a different architecture
- Existing linters don't have this capability baked into their core
Contributing patterns misses the pointβthe integration IS the innovation.
A: Semgrep is excellent and closer to UBS than traditional linters. Key differences:
| Feature | Semgrep | UBS |
|---|---|---|
| Setup | Requires config file + rule selection | Zero config |
| Speed | ~10-20s on medium projects | ~3s (optimized for speed) |
| Target user | Security teams, human developers | LLM agents |
| Rule focus | Security + custom patterns | AI-generated bug patterns |
| Multi-language | β Yes | β Yes |
| Correlation analysis | β Pattern matching only | β Deep guards, metrics |
| LLM integration | Not designed for it | Purpose-built |
Use Semgrep if: You need custom security rules and have time to configure them. Use UBS if: You want instant AI workflow integration with zero setup.
They're complementary. Some users run both.
A: Less than you'd think, and it's acceptable for LLM consumers.
Reality check:
- Layer 1 (ripgrep/regex): ~15-20% false positive rate on some patterns
- Layer 2 (ast-grep/AST): ~2-5% false positive rate (semantic understanding)
- Layer 3 (correlation): ~1-3% false positive rate (contextual analysis)
Blended approach: ~8-12% overall false positive rate.
Why this is OK:
- LLMs don't get frustrated like humans do
- They evaluate findings in 0.8 seconds total
- Better to flag 100 (20 safe) than miss 1 critical bug
- Humans reviewing AI code ALREADY have to check everything anyway
For critical patterns (eval, XSS, hardcoded secrets), we use ast-grep (high precision). For style patterns, we use regex (fast, some FP acceptable).
And we're always improving. Each release reduces FP rate through better heuristics.
A: Controversial choice, but intentional:
Advantages of Bash:
- β Zero dependencies - runs on any Unix-like system
- β Universal availability - every dev machine has Bash 4.0+
- β Shell integration - git hooks, CI/CD, file watchers are natural
- β Module system - each language scanner is standalone
- β Rapid prototyping - adding new patterns is trivial
- β LLM-readable - AI agents can understand and modify rules
Disadvantages:
- β Not as "elegant" as Python
- β String handling can be verbose
- β No static typing
Bottom line: For a tool that orchestrates existing CLI tools (ripgrep, ast-grep, jq, typos) and needs to be universally available, Bash is pragmatic.
Future: Core modules might be rewritten in Rust for speed, but the meta-runner will stay Bash for compatibility.
A: Absolutely! It's optimized for AI workflows, but works great for humans too.
Scenarios where humans love it:
1. Code review speed-up
# Reviewing a PR with 800+ lines
git checkout feature-branch
ubs .
# Instantly see critical issues before deep review2. Legacy code audits
# "What's dangerous in this 10-year-old codebase?"
ubs /path/to/legacy-app
# Finds all the eval(), XSS, memory leaks3. Learning new languages
# "I'm new to Rust, what am I doing wrong?"
ubs . --verbose
# Shows common Rust pitfalls in your code4. Polyglot projects
# Microservices in 5 languages
ubs .
# One scan, all languages checkedHumans appreciate:
- Zero setup (no config files to maintain)
- Fast feedback (3s vs 30s)
- Multi-language support (one command)
- Finding bugs ESLint misses (deep guards)
A: Different focus and scope:
Security scanners (Snyk, Dependabot, etc.):
- Focus: Dependency vulnerabilities
- Checks: npm packages, CVE databases
- Speed: Seconds to minutes
- Output: "Update package X to fix CVE-2024-1234"
UBS:
- Focus: Code-level bugs in YOUR code
- Checks: Logic errors, null safety, memory leaks, security anti-patterns
- Speed: 3-5 seconds
- Output: "You have unguarded null access at line 42"
They're complementary:
βββββββββββββββββββββββββββββββββββββββ
β Complete Security Stack β
βββββββββββββββββββββββββββββββββββββββ€
β Snyk/Dependabot β Dependencies β
β β¨ UBS β Your code bugs β
β SAST tools β Deep security β
β GitHub Advanced β Secrets in Git β
βββββββββββββββββββββββββββββββββββββββ
Security scanners won't catch: "You forgot await and your async function silently fails."
UBS won't catch: "Your version of lodash has a known CVE."
Use both.
A: Probably! The module system makes it easy to add languages.
Current: JavaScript/TypeScript, Python, Go, Rust, Java, C++, Ruby (7 languages)
Roadmap considerations:
- PHP - High demand, lots of legacy code
- Swift - iOS development
- Kotlin - Android development
- Scala - JVM ecosystem
- Elixir - Growing adoption
How we prioritize:
- Community demand (GitHub issues)
- AI coding tool usage (what LLMs generate most)
- Module maintainer availability
Want to contribute? Writing a new module is ~800-1200 lines of Bash. Check the existing modules as templates.
A: No catch. It's MIT licensed.
Philosophy:
- Built by developers, for developers
- AI coding is exploding, quality tools should be accessible
- Open source enables community contributions (more patterns, better detection)
Business model: None currently. This is a community project.
Future possibilities:
- Enterprise support contracts
- Hosted version for teams
- Premium modules for specific frameworks
But the core tool will always be free and open source.
This isn't trying to replace ESLint. It's solving a different problem:
"How do I give LLM coding agents the ability to self-audit across 7 languages with zero configuration overhead and sub-5-second feedback?"
No existing tool does this because:
- Traditional linters are human-first (need auto-fix, low FP tolerance)
- They're single-language focused (polyglot = 7 different tools)
- They're comprehensive, not fast (30s scan time kills AI iteration loops)
- They're not designed for LLM consumption
UBS is purpose-built for the AI coding era.
Use it WITH your existing tools. Let ESLint handle style. Let TypeScript handle types. Let UBS catch the critical bugs that AI agents generate but can't see.
All helper scripts (manifest runner, fixtures, inline analyzers inside ubs) assume a single source of truth: CPython 3.13 managed by uv living inside .venv/ at the repo root.
# 1) Install uv (one-time)
curl -LsSf https://astral.sh/uv/install.sh | sh
# 2) Create the managed environment defined by pyproject.toml / uv.lock
uv sync --python 3.13
# 3) Activate it whenever you work in this repo (puts .venv/bin first on PATH)
source .venv/bin/activate
# 4) Run any Python entrypoint through the env
uv run python test-suite/run_manifest.py --case js-core-buggy
# ...or rely on 'python'/'python3' now that they point at .venv/bin/python3.13Note
Shell scripts that invoke python3 (language modules under modules/, test-suite/run_all.sh, etc.) automatically pick up .venv/bin/python3 as long as the environment is activated or .venv/bin is on your PATH. The pinned pyproject.toml + uv.lock are the single source of truth for this toolchain.
Common uv-powered entrypoints:
uv run python test-suite/run_manifest.py --case js-core-buggyβ run the manifest in CI or locally without manually activating the venv.source .venv/bin/activate && python -m pip listβ verify that every inlinepython3invocation maps to CPython 3.13.uv run python - <<'PY' β¦β mirrors how the language modules embed Python helpers, but now guaranteed to execute inside the managed interpreter.
Need repo-wide scans to ignore generated code or intentionally buggy fixtures (like this projectβs test-suite/)? Drop a .ubsignore at the root.
- Format mirrors
.gitignore: one glob per line,#for comments. - UBS loads
PROJECT/.ubsignoreautomatically; override with--ignore-file=/path/to/file. - Built-in ignores already cover
node_modules, virtualenvs, dist/build/target/vendor, editor caches, and more, so you rarely need to add them yourself. - Use
--suggest-ignoreto print large top-level directories that might deserve an entry (no files are modified automatically). - Inline suppression works for intentional one-offs:
eval("print('safe')") # ubs:ignore. - Every language module receives the ignore list via their
--excludeflag, so skips stay consistent. - This repository ships with a default
.ubsignorethat excludestest-suite/, keeping βrealβ source scans noise-free.
Example:
# Ignore fixtures + build output
test-suite/
dist/
coverage/
UBS ships seven language-focused analyzers. Each category below is scored using the following scale:
- 0 β Not covered
- 1 β Simple heuristics/regex only
- 2 β Multi-signal/static heuristics (context-aware passes)
- 3 β Deep analysis (AST-grep rule packs, taint/dataflow engines, or toolchain integrations such as
cargo clippy)
| Issue Category | JS / TS | Python | Go | C / C++ | Rust | Java | Ruby |
|---|---|---|---|---|---|---|---|
| Null / Nil Safety | 2 β DOM guard & optional-chaining heuristics (cat.1) | 2 β None guard + dataclass fallbacks |
1 β Basic nil/pointer guards | 2 β Raw pointer/nullptr/RAII checks | 3 β Borrow/Option misuse via clippy + rules | 2 β Optional/null equality audits | 1 β Nil guard reminders |
| Numeric & Type Coercion | 2 β NaN/loose equality/float equality (cat.2/4) | 2 β Division-by-zero & float precision | 1 β Limited arithmetic heuristics | 2 β UB risk & narrowing warnings | 2 β Float/overflow watchers (cat.4) | 1 β Basic comparisons only | 1 β Simple arithmetic foot-guns |
| Collections & Memory | 2 β Array mutation/leak detectors | 2 β Dict/list iteration pitfalls | 1 β Slice/map heuristics | 3 β malloc/free, iterator invalidation, UB (cat.1/5/7) | 2 β Vec/String/iterator audits | 2 β Collections & generics misuse | 1 β Enumerator/default mutability hints |
| Async / Concurrency | 3 β AST-grep + fallback for missing await, React hooks dep analyzer |
2 β Async/Await pitfall scans | 3 β Goroutine/channel/context/defer hygiene | 2 β std::thread join + std::async wait tracking |
2 β Async macros, Send/Sync checks | 2 β ExecutorService shutdown, synchronized monitors |
1 β Basic thread/promise hints |
| Error Handling & Logging | 2 β Promise rejection / tryβcatch auditing | 2 β Exception swallow/logging checks | 2 β Error wrapping, panic usage | 2 β Throw-in-dtor, catch-by-value | 2 β Result/expect/panic usage | 2 β Logging best practices, try-with-resources | 1 β Rescue/raise heuristics |
| Security & Taint | 3 β Lightweight taint engine + security heuristics (cat.7) | 2 β Eval/exec/SQL string heuristics | 2 β HTTP/crypto/command checks | 1 β Limited dedicated security (mostly UB) | 2 β Security category (cat.8) | 3 β SQL concat, Runtime.exec, SSL/crypto checks |
2 β Rails mass-assignment, shell/eval warnings |
| Resource Lifecycle & I/O | 3 β AST event-listener/timer/observer tracking + heuristics | 2 β Context-manager & file lifecycle hints | 2 β defer/file close + HTTP resource hygiene |
2 β Thread join/malloc/free & resource correlation | 2 β Drop/RAII heuristics + correlation | 3 β Executor/file stream cleanup detections | 2 β File open/close + block usage hints |
| Build / Tooling Hygiene | 0 β Not covered yet | 2 β uv extras, packaging, notebook hygiene |
2 β Go toolchain sanity (go vet, module drift) |
1 β CMake/CXX standard reminders | 3 β cargo fmt/clippy/test/check integrations |
2 β Maven/Gradle best-effort builds | 2 β Bundler/Rake/AST rule packs |
| Code Quality Markers | 1 β TODO/HACK detectors | 1 | 1 | 1 | 1 | 1 | 1 |
| Domain-Specific Extras | 3 β React hooks, Node I/O, taint flows | 2 β Typing strictness, notebook linting | 2 β Context propagation, HTTP server/client reviews | 2 β Modernization, macro/STL idioms | 3 β Unsafe/FFI audits, cargo inventory | 3 β SQL/Executor/annotation/path handling | 2 β Rails practicals, bundle hygiene |
Use this matrix to decide which language moduleβs findings you want to prioritize or extend. For example, if you need deeper Go resource-lifecycle audits, you can extend category 5 (defer/cleanup) or contribute new AST-grep rules; for JavaScript security you can build on the taint engine already running in category 7.
MIT License - see LICENSE file
TL;DR: Use it anywhere. Modify it. Share it. Commercial use OK. No restrictions.
This project wouldn't exist without:
- ast-grep by Herrington Darkholme - Revolutionary AST tooling that makes semantic analysis accessible
- ripgrep by Andrew Gallant - The fastest search tool ever built
- Open Source Communities - JavaScript, Python, Rust, Go, Java, C++, and Ruby communities for documenting thousands of bug patterns and anti-patterns over decades
- AI Coding Tools - Claude, GPT-5, Cursor, Copilot for inspiring this tool and making development faster
- π Report bugs
- π‘ Request features
- π Documentation
Every hour spent debugging production bugs is an hour not spent building features.
The Ultimate Bug Scanner gives you:
- β Confidence that code won't fail in production
- β Speed (catch bugs in seconds, not hours)
- β Quality gates for AI-generated code
- β Peace of mind when you deploy
curl -fsSL "https://raw.githubusercontent.com/Dicklesworthstone/ultimate_bug_scanner/master/install.sh?$(date +%s)" | bashThen never waste another evening debugging a null pointer exception.
Star this repo if it saved you from a production bug β
MCP Agent Mail is a Git-backed mailbox system that lets your coding agents coordinate work, hand off tasks, and keep durable histories of every change discussion.
- UBS + MCP Agent Mail together: run
ubs --fail-on-warning .as a standard guardrail step in your MCP Agent Mail workflows so any agent proposing code changes must attach a clean scan (or a summary of remaining issues) to their reply. - Ideal pattern: one agent writes or refactors code, a βQA agentβ triggered via MCP Agent Mail runs UBS against the touched paths, then posts a concise findings report back into the same thread for humans or other agents to act on.
- Result: your multi-agent automation keeps all the communication history in MCP Agent Mail while UBS continuously enforces fast, language-agnostic quality checks on every change.