Master Propagate

Offers context menu action to define a master file (like a master slide / canvas in graphics design tools) and spawn children files from it.

Propagates changes from a master file to any number of children on save. Children start as exact copies of the master. When the master is saved, the delta is patched into each child. Conflicts open with Git-style conflict markers so you can resolve them with VS Code's built-in merge editor.

Relationships survive across workspaces and track file renames/moves — including moves made outside VS Code (resolved via content hash fallback).

Setup

npm install
npm run compile

Then press F5 in VS Code to launch the Extension Development Host.

To package for install:

npm install -g @vscode/vsce
vsce package        # produces master-propagate-0.1.0.vsix
code --install-extension master-propagate-0.1.0.vsix

Usage

All commands are available by right-clicking a file in the Explorer.

Command	What it does
Set as Master	Registers the file as a master
Create Child from Master	Creates a copy and links it as a child
Add Existing File as Child	Links a pre-existing file to a master
Unlink File	Removes a master or child from all relationships
Show Relationships	Lists all master→child trees

How propagation works

You save the master file.
The extension diffs the master's previous saved state against the new saved state.
That patch is applied to each child.
If a patch applies cleanly → child is silently updated.
If there's a conflict → child is written with <<<<<<< / ======= / >>>>>>> markers and opened in the editor.

Configuration

masterPropagate.childSnapshotBehavior

Value	Behaviour
`alwaysTrackMaster` (default)	Diffs previous save vs current save — only incremental changes propagate
`snapshotAtCreation`	Diffs master-at-child-creation-time vs current save — full divergence since birth propagates

Disclaimer

This extension was entirely "vibe-coded". I have no experience with JavaScript but I personally needed this tool for one of my workloads.

Master File

higifnr