microsoft/vscode-mock-debug

Starter sample for developing debug adapters for VSCode.

TypeScript

358

443 commits

updated Oct 9, 2026

See the code

README

VS Code Mock Debug

This is a starter sample for developing VS Code debug adapters.

Mock Debug simulates a debug adapter for Visual Studio Code. It supports step, continue, breakpoints, exceptions, and variable access but it is not connected to any real debugger.

The sample is meant as an educational piece showing how to implement a debug adapter for VS Code. It can be used as a starting point for developing a real adapter.

More information about how to develop a new debug adapter can be found here.

Using Mock Debug

  • Install the Mock Debug extension in VS Code.
  • Create a new 'program' file readme.md and enter several lines of arbitrary text.
  • Switch to the debug viewlet and press the gear dropdown.
  • Select the debug environment "Mock Debug".
  • Press the green 'play' button to start debugging.

You can now 'step through' the readme.md file, set and hit breakpoints, and run into exceptions (if the word exception appears in a line).

Mock Debug

Build and Run

  • Clone the project https://github.com/Microsoft/vscode-mock-debug.git
  • Open the project folder in VS Code.
  • Press F5 to build and launch Mock Debug in another VS Code window.
  • In the explorer view of the new window open the 'program' file readme.md
  • Set some breakpoints
  • From the editor's "Run and Debug" toolbar dropdown menu select "Debug File"

microsoft/vscode-mock-debug

Starter sample for developing debug adapters for VSCode.

TypeScript

358

443 commits

updated Oct 9, 2026

See the code

README

VS Code Mock Debug

This is a starter sample for developing VS Code debug adapters.

Mock Debug simulates a debug adapter for Visual Studio Code. It supports step, continue, breakpoints, exceptions, and variable access but it is not connected to any real debugger.

The sample is meant as an educational piece showing how to implement a debug adapter for VS Code. It can be used as a starting point for developing a real adapter.

More information about how to develop a new debug adapter can be found here.

Using Mock Debug

  • Install the Mock Debug extension in VS Code.
  • Create a new 'program' file readme.md and enter several lines of arbitrary text.
  • Switch to the debug viewlet and press the gear dropdown.
  • Select the debug environment "Mock Debug".
  • Press the green 'play' button to start debugging.

You can now 'step through' the readme.md file, set and hit breakpoints, and run into exceptions (if the word exception appears in a line).

Mock Debug

Build and Run

  • Clone the project https://github.com/Microsoft/vscode-mock-debug.git
  • Open the project folder in VS Code.
  • Press F5 to build and launch Mock Debug in another VS Code window.
  • In the explorer view of the new window open the 'program' file readme.md
  • Set some breakpoints
  • From the editor's "Run and Debug" toolbar dropdown menu select "Debug File"

Significant stargazers

Yosh

3,424 followers · starred Feb 2022

Andreas Kohn

80 followers · starred Oct 2020

Hongbo Zhang

1,741 followers · starred Aug 2024

Felix Becker

585 followers · starred Dec 2015