Debugging JavaScript and TypeScript

The platform's JS / TS debugger is Graalium's debug bridge. Hit a breakpoint in your .js / .mjs / .ts file, the JVM pauses the script, and the IDE inspects state in the JavaScript debugger view.

Prerequisites

• Debug mode is enabled by default in the official Docker image (DIRIGIBLE_GRAALIUM_ENABLE_DEBUG=true).
• The Graalium debug port is 8081 (env DIRIGIBLE_JAVASCRIPT_GRAALVM_DEBUGGER_PORT).
• For self-hosted runs, start the JVM with debug enabled.

Workflow

1. Open the .ts / .js file in Monaco.
2. Click in the gutter to set a breakpoint - the red dot appears.
3. Run the endpoint - hit it via the browser, curl, or the Swagger view.
4. The script pauses; the JavaScript debugger view opens with call stack, locals, watch, and step controls.
5. Step over (F10), step into (F11), step out (Shift+F11), continue (F8). Variables resolve in the locals tree; watch expressions live in the panel beside the stack.

Conditional breakpoints

Right-click a breakpoint to set a condition. The script pauses only when the JS expression evaluates truthy.

Source maps

TypeScript files debug at the source level - the Monaco breakpoint sits on the .ts line, not the transpiled .js. Source maps are produced as part of the on-demand transpile.

See also

• JavaScript debugger view
• Debugging Java
• Monaco editor