Welcome to Typefusion!

Table of Contents

• Welcome to Typefusion!
  • Table of Contents
  • Introduction
  • Key Features
  • Getting Started
  • Usage
    • CLI
    • Library
  • Typefusion Ref
  • Examples
  • Documentation
  • Effect Integration
  • Troubleshooting
    • The graph is empty when I run Typefusion
    • I'm seeing undefined errors for script imports
  • Contributing

Introduction

Typefusion allows you to run TypeScript scripts and materialize the results into a database. It enables you to create complex workflows by allowing scripts to reference each other's results. Inspired by Data Build Tool (DBT).

Key Features

• Execute TypeScript scripts and store results in your database
• Create complex workflows with script dependencies
• Type-safe references between scripts
• Flexible usage through CLI and library modes
• Automatic dependency resolution and execution order

Getting Started

To begin using Typefusion, follow these steps:

1. Install Typefusion using your preferred package manager:

   npm install typefusion
   # or
   pnpm install typefusion
   # or
   yarn add typefusion
   # or
   bun add typefusion

2. Configure your database connection using one of these methods (PostgreSQL and MySQL are supported):

   • Set a full connection string in the PG_DATABASE_URL or MYSQL_DATABASE_URL environment variable.
   • Set individual environment variables: PG_DATABASE, PG_HOST, PG_PORT, PG_PASSWORD, and PG_USER (for postgres) or MYSQL_DATABASE, MYSQL_HOST, MYSQL_PORT, MYSQL_PASSWORD, and MYSQL_USER (for mysql).

3. Create a directory for your scripts (e.g., workflows).

4. Write your TypeScript scripts in the created directory.

5. Compile your TypeScript scripts into your desired output directory (e.g. scripts). Typefusion runs on the compiled JavaScript output, so ensure you don't bundle your scripts to preserve the directory layout. Avoid outputting to directories like dist or build (see Troubleshooting)

Usage

After following the above instructions, create a script file in the directory, for example, main.ts:

// or mySqlType for mysql
import { pgType, typefusionRef, TypefusionDbResult } from "typefusion";

const mainSchema = {
  id: pgType.integer().notNull(),
  name: pgType.text().notNull(),
  age: pgType.integer().notNull(),
  email: pgType.text().notNull(),
  address: pgType.text().notNull(),
};

export default {
  name: "main",
  schema: mainSchema,
  resultDatabase: "postgresql",
  run: async () => {
    console.log("running main");
    return [
      {
        id: 1,
        name: "John Doe",
        age: 30,
        email: "[email protected]",
        address: "123 Main St",
      },
    ];
  },
} satisfies TypefusionDbResult<typeof mainSchema>;

Warning: Typefusion is native ESM and does not provide a CommonJS export.

Typefusion can be used in two primary modes: CLI and library. Both modes offer similar functionality, allowing you to choose the most suitable approach for your project.

CLI

The Typefusion CLI provides a convenient way to run your scripts from the command line. To use the CLI:

1. Add a script to your package.json:

   "scripts": {
     "run-typefusion": "dotenv -- typefusion ./scripts"
   }

   This example assumes you're using dotenv for environment variable management and that your compiled scripts are in the ./scripts directory.

2. Run your scripts:

   npm run run-typefusion

To explore all CLI options, run:

npm run typefusion --help

Library

You can also use Typefusion as a library in your TypeScript projects:

import typefusion from "typefusion";

await typefusion({
  directory: "./scripts",
});

This approach allows for more programmatic control and integration with your existing TypeScript applications.

Typefusion Ref

Typefusion Refs enable you to reference the results of one script in another, facilitating the creation of complex workflows. Here's an example:

// or mySqlType for mysql
import { pgType, typefusionRef, TypefusionDbResult } from "typefusion";
import main from "./main.js";

const smallSchema = {
  small: pgType.text().notNull(),
};

export default {
  name: "typefusion_ref",
  schema: smallSchema,
  resultDatabase: "postgresql",
  run: async () => {
    const result = await typefusionRef(main);
    console.log("typefusion ref main result", result);
    return [
      {
        small: "smallString" as const,
      },
    ];
  },
} satisfies TypefusionDbResult<typeof smallSchema>;

For cases where you only need the table name without fetching the full data, use the typefusionRefTableName function:

import { typefusionRefTableName } from "typefusion";
import main from "./main.js";

const tableName = await typefusionRefTableName(main);
console.log("typefusion ref table name", tableName); // Outputs: "main"

Examples

To help you get started, we've provided several examples:

1. Basic Usage
2. Using Typefusion Ref

Find more examples in the examples directory.

Documentation

For detailed API documentation, visit the reference docs. The documentation is generated from JSDoc comments in the source code, providing comprehensive information on usage and features.

Effect Integration

Typefusion is built with Effect. Refer to the reference docs for details on Effect-suffixed functions and their usage.

Troubleshooting

The graph is empty when I run Typefusion

This can happen because the library Typefusion depends on to generate the dependency graph ignores common build directories by default. For example, you cannot output scripts to build, dist, and several others (full list here).

I'm seeing undefined errors for script imports

The recommended way to define your script function is using a default export and named function (not an anonymous function). The function does not have to be async. This way, Typefusion can properly resolve your module. Typefusion does not use any compiler magic or do any sort of file parsing.

---

If you encounter any other issues while using Typefusion:

1. Check the GitHub Issues to see if your problem has been reported or resolved.
2. Ensure you're using the latest version of Typefusion.
3. Verify your database connection settings and environment variables.
4. If the issue persists, please open a new issue.

Contributing

Contributions to Typefusion are welcome! To contribute:

1. Fork the repository and create your branch from main.
2. If you've added code that should be tested, add tests.
3. Ensure your code passes all tests and linting rules.
4. Open a pull request with the provided template.

If it's a larger change, please open an issue to discuss your proposed changes or feature additions.