elm-devtool

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Elm DevTool (Proof of Concept)

The Elm 0.18 debugger works on popup window. This project aims to figure out

• Possibility of making it work in Chrome's DevTools window
• How hard to migrate current debugger

Screen capture

How to try

1. Let Chrome read package directory as an extension.
2. cd test and sh build.sh, then open index.html.
3. Select Elm tab in DevTools.
4. Drag the object (This triggers rendering).

Maybe this works. Please tell me if it was wrong.

How it works

The same script app.js works in both main page and devtools panel (which I call "front-end" and "back-end" respectively). Front-end program sends msg to back-end, and back-end program receives and processes it.

This requires some changes in elm-lang/virtual-dom package, but it is not a great deal.

The difficulty

Content Security Policy. Chrome Extension does not allow foreign script, so app.js cannot work without putting unsafe-eval into content_security_policy property in manifest.json.

"content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'"

How to solve

1. Make back-end script static (independent on application logic).
2. Don't use update function in back-end. So front-end should be "update as a service".