Patch for WebAssembly

[mglaman]

Build a version of patch for WebAssembly to allow patching files inside of the WebAssembly runtime instead of in the archive (and not in composer.json)

[mglaman]

    <script src="patch.js"></script>
    <script>
        function applyPatch() {
            // Load files into Emscripten FS
            FS.writeFile('/file_to_patch', 'Original file content');
            FS.writeFile('/patch_file', 'Patch content');

            // Perform patching
            Module.ccall('apply_patch', 'number', ['string', 'string'], ['/file_to_patch', '/patch_file']);

            // Get the result
            const patchedFile = FS.readFile('/file_to_patch', { encoding: 'utf8' });
            console.log('Patched File:', patchedFile);
        }

        Module.onRuntimeInitialized = applyPatch;
    </script>

roughly

[mglaman]

emcc -o patch.js patch.c -s EXPORTED_FUNCTIONS="['_main', '_apply_patch']" -s EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]'