--== THE PROBLEM OF FRESH 2 DEBUG [2026] ==--

[chriswang-]

I want to open a new issue to share my experience more clearly.

To be honest, I really like Deno and Fresh, and I want to upgrade to Fresh 2. However, I have spent a significant amount of time trying to migrate from Fresh 1.x to Fresh 2, and during this process I discovered a serious blocking problem: there is currently no reliable way to debug server-side application code in Fresh 2.

This is not a minor DX inconvenience. For any non-trivial or business-critical website, the inability to properly debug server-side logic is a major problem. Having to rely only on console.log for debugging complex application logic is not realistic and quickly becomes a disaster as the codebase grows.

What makes this more frustrating is that this issue has existed for a long time. I have tried different configurations, inspector flags, source map options, and workflows, and I have also followed related issues and discussions over the past years, but there still does not seem to be a workable, officially supported debugging solution for Fresh 2 (especially with Vite).

I am raising this issue because I genuinely care about the future of Fresh. Solving the debugging problem would be a significant improvement and would make Fresh much more viable for larger and more complex applications.

I also want to be honest about my confusion regarding the move to Vite. In Fresh 1.x, hot reload already worked well, and server-side debugging in VS Code was straightforward. From my perspective as an application developer, I do not see a clear benefit that offsets the loss of effective debugging. If Vite is a necessary architectural direction, then I believe Fresh should provide either:

a reliable, first-class debugging experience, or

a clearly documented and supported alternative debugging workflow.

My hope is that the Fresh team can either address this debugging limitation directly, or at least provide a practical and supported workaround. I believe this would be very beneficial for Fresh’s long-term adoption and growth.

For reference, this debugging problem has been discussed before and appears to be recurring rather than isolated:

#2075
#3515

[Midqiu]

I tried this, it works.

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Debug Fresh Dev (Vite)",
      "type": "node",
      "request": "launch",
      "program": "${workspaceFolder}/node_modules/.bin/vite",
      "cwd": "${workspaceFolder}",
      "runtimeExecutable": "deno",
      "runtimeArgs": ["run", "-A", "--inspect"],
      "attachSimplePort": 9229
    },
    {
      "name": "Debug Fresh Server",
      "type": "node",
      "request": "launch",
      "program": "${workspaceFolder}/_fresh/server.js",
      "cwd": "${workspaceFolder}",
      "runtimeExecutable": "deno",
      "runtimeArgs": ["serve", "-A", "--inspect"],
      "attachSimplePort": 9229
    }
  ]
}

by the way, it's the github copilot telled me.

[chriswang-]

Hi @Midqiu

I tested your configuration and found it to be very unstable.
Sometimes the breakpoints suddenly start working, but I’m not sure why.
Once I run deno cache --reload main.ts, the breakpoints stop working again.

You can also reproduce this issue using my example project.
https://github.com/user-attachments/files/22683583/fresh-project.zip