Contributing

Setup

git clone https://github.com/gdpotter/pgmt.git
cd pgmt
./scripts/test-setup.sh    # Start PostgreSQL containers
cargo test                  # Run tests

Prerequisites: Rust 1.74+, Docker

Code Style

• cargo fmt before committing
• cargo clippy -- -D warnings - no warnings
• Use anyhow::Result for errors
• All SQL queries use sqlx compile-time verification
• Tests required for new features

Adding Database Object Support

Each object type needs:

1. Catalog module (src/catalog/object.rs)

   • fetch() function using PostgreSQL system catalogs
   • Include comment: Option<String> field
   • Implement DependsOn and Commentable traits

2. Diff logic (src/diff/object.rs)

   • Compare old vs new states
   • Generate CREATE, DROP, ALTER operations
   • Handle comment changes with diff_comments()

3. Migration operations (src/diff/operations/)

   • Define operation enums
   • Implement SqlRenderer trait

4. Tests (tests/catalog/ and tests/migrations/)

Look at src/catalog/triggers.rs for a pattern to follow.

Testing

// Isolated test database
#[tokio::test]
async fn test_fetch() {
    with_test_db(async |db| {
        db.execute("CREATE TABLE users (id INT)").await;
        let tables = fetch(db.pool()).await.unwrap();
        assert_eq!(tables.len(), 1);
    }).await;
}

// Migration testing
#[tokio::test]
async fn test_migration() {
    let helper = MigrationTestHelper::new().await;
    helper.run_migration_test(
        &[],  // Both databases
        &[],  // Initial only
        &["CREATE TABLE users (id INT)"],  // Target only
        |steps, _| {
            assert!(!steps.is_empty());
            Ok(())
        }
    ).await;
}

Pull Requests

Before submitting:

cargo test
cargo fmt
cargo clippy -- -D warnings
SQLX_OFFLINE=true cargo build

PR requirements:

• Clear description of changes
• Tests pass
• No clippy warnings
• sqlx metadata committed (.sqlx/ files)

Reporting Issues

Include: pgmt version, PostgreSQL version, OS, full error messages, steps to reproduce.

Code Organization

Directory	Purpose
catalog/	PostgreSQL introspection
diff/	Schema comparison
commands/	CLI implementations
config/	Configuration
schema_loader/	Multi-file schema loading
render/	SQL generation