name: fixture-tricky
description: >
Generate adversarial PDF content that breaks extractors. Creates false-positive
tables, malformed tables, cursed text, and layout traps. Extensible registry
for adding new edge cases discovered from real-world PDFs.
allowed-tools: Bash, Read, Write
triggers:
- create tricky pdf
- false positive table
- malformed table
- broken table
- extractor edge case
- adversarial pdf
- cursed text
metadata:
short-description: Adversarial PDF content for extractor stress testing

Fixture Tricky Skill

Generate adversarial PDF content designed to expose extractor bugs. Continuously
extensible as new edge cases are discovered from real-world PDFs.

Why This Exists

Real-world PDFs contain patterns that reliably break extractors:
- Text that Camelot/Marker falsely detect as tables
- Tables corrupted by Word/PDF conversions
- Text with ligatures, special characters, mixed directions
- Layout patterns that confuse section detection

This skill creates reproducible test cases for these issues.

Quick Start

cd .pi/skills/fixture-tricky

# Generate false-positive table content
uv run generate.py false-tables --output false_tables.pdf

# Generate malformed/corrupted tables
uv run generate.py malformed-tables --output malformed.pdf

# Generate text extraction nightmares
uv run generate.py cursed-text --output cursed.pdf

# Generate layout traps
uv run generate.py layout-traps --output layout.pdf

# All-in-one stress test
uv run generate.py gauntlet --output gauntlet.pdf

# List all available tricks
uv run generate.py list-tricks

Trick Categories

False-Positive Tables (false-tables)

Text patterns that extractors incorrectly identify as tables:

Malformed Tables (malformed-tables)

Real tables with structural problems:

Cursed Text (cursed-text)

Text extraction nightmares:

Layout Traps (layout-traps)

Structure/layout patterns that confuse extractors:

Adding New Tricks

Tricks are registered in tricks/registry.py. To add a new trick:

# In tricks/registry.py
from .my_new_trick import generate_my_trick

TRICKS["my-new-trick"] = {
    "category": "false-tables",  # or malformed-tables, cursed-text, layout-traps
    "description": "Description of what this trick tests",
    "generator": generate_my_trick,
}

Or add directly to generate.py in the appropriate category dict.

Integration with pdf-fixture

Use with pdf-fixture to create comprehensive test suites:

# Generate clean fixture
cd ../pdf-fixture && uv run generate.py simple --output clean.pdf

# Generate tricky fixture
cd ../fixture-tricky && uv run generate.py gauntlet --output tricky.pdf

# Compare extractor results on both

Real-World Discovery Workflow

When you find a PDF that breaks the extractor:

1. Identify the problematic pattern
2. Add a new trick that reproduces it minimally
3. Run skills-sync to broadcast
4. Use the trick in regression testing

# Example: Found a PDF where Camelot detects email signatures as tables
uv run generate.py add-trick \
  --name "email-signature" \
  --category "false-tables" \
  --description "Email signature blocks with name/title/phone"

Dependencies

dependencies = [
    "pymupdf>=1.23.0",
    "reportlab>=4.0.0",
    "typer>=0.9.0",
]