LIGO Debugger (Early Alpha Preview)

A Visual Studio Code extension that provides LIGO debugging capability.

Note: This package is in a very early alpha version, released as a preview. Bugs are to be expected!

In the future, this package will be deprecated and joined with the LIGO Language Server (ligo-vscode).

To use this package, you need to have LIGO version 0.47.0 or greater available in your PATH.

Currently, simple contracts are supported, with support for more complex contracts on the way.

Running the debugger

You can press F5 to start debugging a LIGO contract. Upon the launch of the debugger, you will be asked for a value for the parameter, and a value for the storage. For now, you can provide a LIGO entrypoint in your launch.json, or the extension will default to main if none is provided.

Use F11 (or press "Step Into") to step through LIGO code in details.

Launch configuration

Passing parameter and storage

The parameter and storage fields define what will be passed as run arguments.

It is possible to hardcode a concrete value. However, usually you might prefer using the auto-generated values like ${command:AskForParameter} that would request the actual value upon starting a debug session.

In both cases you can use complex expressions, e.g. { a = 1; b = 2 } for record definition or even let x = 9 in x * x + 5 in Cameligo. The dialect of the passed expressions must match the dialect of the contract.

It is possible to refer to constants declared in the contract and even call functions.

In case you need to supply a value in the lower-level Michelson format, prefix it with michelson: or just m:

m:Pair 1 "a"

Specifying a Michelson entrypoint

When the parameter of your contract has multiple constructors, normally you can just pass something like Constructor1 5 as a parameter.

In case of nested constructors, it might be simpler to specify the bottom-most constructor name (which generally must be unique across the contract) and its argument. The underlying Michelson engine allows for this.

To make it work, set michelsonEntrypoint field to the entrypoint name. Example:

type subparameterX =
  | CallX1 of int
  | CallX2 of string

type parameter =
  | CallX of subparameterX
  | CallY

With such a contract, you can specify in launch.json:

{
    "michelsonEntrypoint": "CallX1",
    "parameter": 5
}