feat: Initial pysql-test framework implementation

- Set up Poetry-based project with pyproject.toml (canonical Python setup)
- Implement PgTestClient with transaction management (before_each/after_each)
- Implement PgTestConnector for connection pool management
- Implement DbAdmin for database creation/dropping
- Implement get_connections() entry point for test setup
- Add composable seed adapters (sqlfile, fn, compose)
- Add comprehensive test suite (21 tests)
- Configure ruff for linting and mypy for type checking
- Add comprehensive README with usage examples

Author: pyramation

.gitignore

@@ -0,0 +1,79 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# ruff
+.ruff_cache/
+
+# OS
+.DS_Store
+Thumbs.db

README.md

@@ -1 +1,198 @@
-pysql
+# pysql-test
+
+PostgreSQL testing framework for Python - instant, isolated databases with automatic transaction rollback.
+
+## Features
+
+- **Instant isolated databases**: Each test gets a fresh database with a unique UUID name
+- **Transaction rollback**: Changes are automatically rolled back after each test
+- **Composable seeding**: Seed your database with SQL files, custom functions, or combine multiple strategies
+- **RLS testing support**: Easy context switching for testing Row Level Security policies
+- **Clean API**: Simple, intuitive interface inspired by the Node.js pgsql-test library
+
+## Installation
+
+```bash
+# Using Poetry (recommended)
+poetry add pysql-test
+
+# Using pip
+pip install pysql-test
+```
+
+## Quick Start
+
+```python
+import pytest
+from pysql_test import get_connections, seed
+
+# Basic usage
+def test_basic_query():
+    conn = get_connections()
+    result = conn.db.query('SELECT 1 as value')
+    assert result.rows[0]['value'] == 1
+    conn.teardown()
+
+# With pytest fixture
+@pytest.fixture
+def db():
+    conn = get_connections()
+    yield conn.db
+    conn.teardown()
+
+def test_with_fixture(db):
+    result = db.query('SELECT 1 as value')
+    assert result.rows[0]['value'] == 1
+
+# With SQL file seeding
+@pytest.fixture
+def seeded_db():
+    conn = get_connections(
+        seed_adapters=[seed.sqlfile(['schema.sql', 'fixtures.sql'])]
+    )
+    yield conn.db
+    conn.teardown()
+
+def test_with_seeding(seeded_db):
+    users = seeded_db.many('SELECT * FROM users')
+    assert len(users) > 0
+```
+
+## Transaction Isolation
+
+Use `before_each()` and `after_each()` for per-test isolation:
+
+```python
+@pytest.fixture
+def db():
+    conn = get_connections(
+        seed_adapters=[seed.sqlfile(['schema.sql'])]
+    )
+    db = conn.db
+    db.before_each()  # Begin transaction + savepoint
+    yield db
+    db.after_each()   # Rollback to savepoint
+    conn.teardown()
+
+def test_insert_user(db):
+    # This insert will be rolled back after the test
+    db.execute("INSERT INTO users (name) VALUES ('Test User')")
+    result = db.one("SELECT * FROM users WHERE name = 'Test User'")
+    assert result['name'] == 'Test User'
+
+def test_user_count(db):
+    # Previous test's insert is not visible here
+    result = db.one("SELECT COUNT(*) as count FROM users")
+    assert result['count'] == 0  # Only seeded data
+```
+
+## RLS Testing
+
+Test Row Level Security policies by switching contexts:
+
+```python
+def test_rls_policy(db):
+    db.before_each()
+    
+    # Set the user context
+    db.set_context({'app.user_id': '123'})
+    
+    # Now queries will be filtered by RLS policies
+    result = db.many('SELECT * FROM user_data')
+    
+    db.after_each()
+```
+
+## Seeding Strategies
+
+### SQL Files
+
+```python
+seed.sqlfile(['schema.sql', 'fixtures.sql'])
+```
+
+### Custom Functions
+
+```python
+seed.fn(lambda ctx: ctx['pg'].execute(
+    "INSERT INTO users (name) VALUES (%s)", ('Alice',)
+))
+```
+
+### Composed Seeding
+
+```python
+seed.compose([
+    seed.sqlfile(['schema.sql']),
+    seed.fn(lambda ctx: ctx['pg'].execute("INSERT INTO ...")),
+])
+```
+
+## Configuration
+
+Configure via environment variables:
+
+```bash
+export PGHOST=localhost
+export PGPORT=5432
+export PGUSER=postgres
+export PGPASSWORD=your_password
+```
+
+Or pass configuration directly:
+
+```python
+conn = get_connections(
+    pg_config={
+        'host': 'localhost',
+        'port': 5432,
+        'user': 'postgres',
+        'password': 'your_password',
+    }
+)
+```
+
+## API Reference
+
+### `get_connections(pg_config?, connection_options?, seed_adapters?)`
+
+Creates a new isolated test database and returns connection objects.
+
+Returns a `ConnectionResult` with:
+- `pg`: PgTestClient connected as superuser
+- `db`: PgTestClient for testing (same as pg for now)
+- `admin`: DbAdmin for database management
+- `manager`: PgTestConnector managing connections
+- `teardown()`: Function to clean up
+
+### `PgTestClient`
+
+- `query(sql, params?)`: Execute SQL and return QueryResult
+- `one(sql, params?)`: Return exactly one row
+- `one_or_none(sql, params?)`: Return one row or None
+- `many(sql, params?)`: Return multiple rows
+- `many_or_none(sql, params?)`: Return rows (may be empty)
+- `execute(sql, params?)`: Execute and return affected row count
+- `before_each()`: Start test isolation (transaction + savepoint)
+- `after_each()`: End test isolation (rollback)
+- `set_context(dict)`: Set session variables for RLS testing
+
+## Development
+
+```bash
+# Install dependencies
+poetry install
+
+# Run tests
+poetry run pytest
+
+# Run linting
+poetry run ruff check .
+
+# Run type checking
+poetry run mypy src
+```
+
+## License
+
+MIT