Scripting in TypeScript

JavaScript is the programming language of the web. It's dynamically typed, meaning variable types are resolved at runtime rather than at compile time.

TypeScript is a superset of JavaScript. It adds optional static typing, catching errors at the authoring stage rather than at runtime. TypeScript is not a separate runtime; it compiles down to plain JavaScript before execution. The platform only ever runs JavaScript; TypeScript is purely a developer experience improvement.

For Groovy developers, TypeScript will feel familiar: like Java, it uses explicit types and surfaces mistakes early.

ScriptRunner for Jira Isolated Cloud is built on Atlassian Forge, and all scripting features use TypeScript. When you save a script, ScriptRunner compiles your TypeScript to JavaScript automatically — you write TypeScript, the platform handles the rest.

Moving from Groovy to TypeScript involves the following main adjustments:

• Syntax differences: TypeScript uses different conventions for variables, functions, objects, and iteration. The Groovy vs TypeScript Fundamentals and TypeScript Syntax Quick Reference pages cover these in detail.
• Asynchronous programming: In Groovy, API calls are synchronous. In TypeScript, they return Promises and require async / await. This is the biggest conceptual shift, and the Understanding Async and Await page explains it thoroughly.
• Making HTTP requests: In Groovy, you used Unirest or HttpBuilder. In TypeScript, you use the built-in Fetch API. The Make API Calls with Fetch page covers this in detail.

The underlying logic of your scripts translates directly. The language is different; the thinking is the same.