DeployProof

Deterministic pre-push verification for AI-assisted codebases: AST mutation testing, credential scanning, sandbox-escape detection, mock-usage alerts, swallowed-exception checks, and dependency hallucination defense.

Why This Exists

AI-assisted development introduces subtle failure modes that standard linters and coverage tools miss: test suites with high line coverage but near-zero mutation scores, hardcoded credentials generated in passing, symlinks that deceive approval prompts into escaping the repository sandbox, silently swallowed exceptions, and package names hallucinated by LLMs that don't exist on PyPI. DeployProof catches these at the pre-push stage, before they reach CI or production.

Install

pip install deployproof

Requires Python 3.10+.

Quickstart

Initialize in your repository:

deployproof init

Run all verification checks against changes in the current session (git diff):

deployproof check

Output includes a section for each check — symlink scan, secrets scan, dependency scan, mock detection, control flow analysis, and mutation score — with a pass/fail line at the bottom.

Exit Codes:

• 0 — PASSED: All verification checks passed and mutation score meets threshold.
• 1 — FAILED: Code quality or security gate triggered (mutation score below threshold, untested files, hardcoded secrets, sandbox-escape symlinks, hallucinated packages, or strict flags).
• 2 — ERROR: Test environment failure (test suite failed to collect or execute before mutation testing began due to missing dependencies or broken imports).

Example Walkthrough

Given a newly written function calculator.py:

def calculate_discount(price: float, rate: float) -> float:
    if rate > 0.5:
        return price * 0.5
    return price * (1.0 - rate)

With an AI-generated test that achieves 100% line coverage by only asserting standard discounts (rate = 0.2):

def test_calculate_discount_basic():
    assert calculate_discount(100.0, 0.2) == 80.0

Running deployproof check mutates AST operators and detects that boundary conditions and threshold caps are untested:

$ deployproof check

DeployProof - LOCAL PRE-CHECK (approximate) - not the verified score
====================================================================

Target Scope (1 file evaluated):
  * calculator.py

Symlink & Sandbox Escape Scan (CWE-61/CWE-451):
  Clean: No symlinks or sandbox-escape traversal links detected across 1 session file.

Secrets & Credentials Pre-Push Scan:
  Clean: No hardcoded secrets or tracked .env files detected across 1 session file.

Dependency & Slopsquatting Scan (PyPI Registry & Age Analysis):
  Clean: No new external packages introduced across 1 session file.

Mock Usage Introduced (flagged for review):
  Clean: No modified test files in scope.

Control Flow & Error Handling (flagged for review):
  Clean: No bare excepts, swallowed exceptions, or unreachable code detected across 1 session file.

Local Pre-Check Mutation Verification:
  Score:  57.1% (4/7 mutants killed)
  Status: FAILED (score 57.1% below 80.0%) (threshold: 80.0%)
  Time:   2.27s

Skipped Constructs: None (No known unsupported constructs detected)

Surviving Mutants (3 unverified changes):

  [1] calculator.py:2
      Mutation: Replace numeric constant '0.5' with '1.5'
      Original: if rate > 0.5:
      Mutated:  if rate > 1.5:

  [2] calculator.py:3
      Mutation: Replace numeric constant '0.5' with '1.5'
      Original: return price * 0.5
      Mutated:  return price * 1.5

  [3] calculator.py:3
      Mutation: Replace binary operator '*' with '/'
      Original: return price * 0.5
      Mutated:  return price / 0.5

====================================================================
Notice: Local pre-check only. Full verified score runs in CI on push (via mutmut).
Pre-check FAILED: Score 57.1% is below threshold 80.0% (3 surviving mutants).

Adding tests for threshold cap (rate = 0.8) and exact boundary (rate = 0.5) kills all mutants:

Local Pre-Check Mutation Verification:
  Score:  100.0% (7/7 mutants killed)
  Status: PASSED (threshold: 80.0%)
  Time:   2.31s

Surviving Mutants: None (All generated mutants caught by test suite)

====================================================================
Notice: Local pre-check only. Full verified score runs in CI on push (via mutmut).
Pre-check clean: 100% of tested basic mutations caught.

CLI Options & Flags

Note: deployproof check --wsl (Windows only) is newer and less battle-tested than the core checks — file an issue if you hit something.

Machine-Readable Output (--json)

DeployProof provides a stable structured JSON schema for CI/CD pipelines, IDEs, and automation:

deployproof check --json

JSON Output Schema

{
  "version": "0.2.1",
  "status": "passed",
  "summary": {
    "target_files_count": 1,
    "mutation_score": 100.0,
    "threshold": 80.0,
    "secrets_found": 0,
    "symlink_escapes_found": 0,
    "dependency_findings": {
      "high_risk": 0,
      "medium_risk": 0,
      "ok": 1,
      "unknown": 0,
      "unscanned": 0
    },
    "mock_usages_found": 0,
    "control_flow_findings": 0,
    "strict_mocks_active": false,
    "strict_mocks_triggered": false,
    "strict_error_handling_active": false,
    "strict_error_handling_triggered": false
  },
  "scope": {
    "target_files": [
      {
        "file": "app.py",
        "loc": 45,
        "is_large": false
      }
    ]
  },
  "mutation_testing": {
    "score": 100.0,
    "threshold": 80.0,
    "total_mutants": 6,
    "killed_mutants": 6,
    "survived_mutants_count": 0,
    "duration_seconds": 1.2,
    "surviving_mutants": [],
    "skipped_constructs": [],
    "untested_files": []
  },
  "secrets": {
    "clean": true,
    "files_scanned": 1,
    "findings": []
  },
  "symlinks": {
    "clean": true,
    "files_scanned": 1,
    "findings": []
  },
  "dependencies": {
    "clean": true,
    "total_scanned": 1,
    "findings": [],
    "unscanned_sources": []
  },
  "mocks": {
    "clean": true,
    "strict_gate_triggered": false,
    "findings": []
  },
  "control_flow": {
    "clean": true,
    "strict_gate_triggered": false,
    "findings": []
  }
}

What It Checks

• Mutation Score — Mutates AST operators (>=, ==, and, or, *, numeric constants, comparisons) in modified files and runs your test suite against each mutant. Reports surviving mutants and a percentage score. Does not use line coverage. Features atomic file restoration protected by SIGINT/SIGTERM/SIGBREAK signal handlers to ensure interrupted runs never leave mutated code on disk.
• Secrets and Credentials — Scans modified files for hardcoded API keys (OpenAI, Anthropic, AWS, GitHub, Stripe, private keys) and tracked .env files using pattern matching and entropy analysis.
• Symlink and Sandbox Escape — Resolves symbolic links and flags any whose target escapes the repository root (CWE-61 / CWE-451). Catches the class of path-traversal trick used in the GhostApproval disclosure (Wiz Research, July 2026).
• Dependency and Slopsquatting — For each new import, dynamic import (importlib.import_module, __import__), or manifest entry (including recursive -r includes) introduced in the diff, queries the PyPI JSON API and checks registration age. Packages that don't exist (HTTP 404) are flagged HIGH RISK; packages registered within the last 30 days are flagged MEDIUM RISK.
• Mock Usage Detection — Scans test diffs for newly introduced imports or fixture uses of unittest.mock, mocker, and monkeypatch, flagging them for human review with an optional --strict-mocks hard gate.
• Control Flow and Error Handling — AST-based detector for bare except: without re-raise, silently swallowed broad exceptions (except Exception: that only pass or log/print without re-raising or returning error indicators), and dead/unreachable code following unconditional return, raise, break, or continue, with an optional --strict-error-handling hard gate.

What This Doesn't Do

• Test-only diffs are not yet caught. If a diff modifies or weakens assertions in a test file without changing the corresponding source file, DeployProof currently sees zero modified source lines and passes with 0 mutants evaluated. This is a known gap — see INVESTIGATION_blastradius.md for the reverse-mapping approach being evaluated to close it. Until this lands, DeployProof does not protect against test suites being weakened directly.
• Not a full-repo audit. Checks are scoped to files changed in the current session (git diff). Files you haven't touched are not re-evaluated.
• Python only. Mutation testing and import extraction currently support Python files only. Other languages are not scanned.
• No auto-fix. DeployProof reports findings; it does not modify your code, rewrite imports, or suggest patches.
• No IDE plugin yet. There is no VS Code extension or JetBrains plugin. The CLI is the interface. IDE integration is on the roadmap.

See It Catch Real Bugs

Clone this repository and run the standalone stress-test suite to see DeployProof evaluate 11 planted edge cases:

python stress_fixtures/run_stress_tests.py

Fixtures cover weak test suites, zero-test orphan modules, planted OpenAI/AWS credentials, GhostApproval sandbox-escape traps, swallowed exceptions/dead code, and mock-masked broken implementations.

Status & Roadmap

• Current (v0.2.1): Diff-scoped AST mutation testing (with recursive test//tests/ discovery, AST column-offset snippet reconstruction, and SIGINT/SIGTERM/SIGBREAK signal-safe disk restoration), baseline test-collection failure isolation with distinct exit code 2, entropy-driven value-based secrets scanner (including unquoted .env values and prefix validation), GhostApproval symlink sandbox-escape detector, PyPI dependency hallucination / slopsquatting scanner (with import-to-distribution translation, recursive -r requirements scanning, and dynamic import detection via importlib / __import__), mock-introduction detector (--strict-mocks), control-flow / swallowed-exception scanner (--strict-error-handling), 11/11 launch-day stress test suite, 94 unit tests, machine-readable --json output, and Tier 2 CI verification via GitHub Actions (mutmut).
• Next: Multi-language mutation support and expanded ecosystem rule packs.

Contributing

Issues and pull requests are welcome. Open an issue first for significant changes so the approach can be discussed before implementation.

License

MIT. See LICENSE.

Created by SVS Praveen · Portfolio · LinkedIn