patch-package uses patches with filenames like @scope+pkg+1.2.3.patch and content containing node_modules/ prefixes.

pnpm uses patches with filenames like @scope__pkg@1.2.3.patch and content without node_modules/ prefixes.

Features

Scans for patch files (default ./patches directory) when processing config files
Normalizes the path, then performs conversion: content rewrite + filename rewrite
Aggregates results into patchedDependencies entries, writes them back to config
Runs pnpm install automatically via workflow step to apply the patches

Detection: converts only if patch content includes node_modules diff headers (diff --git a/node_modules/..., -- a/node_modules/..., +++ b/node_modules/...)
Prefix calculation: derives a removal pattern from the patch filename by taking all +separated parts except the last (version), joining with /, and prefixing with node_modules
Rewrite: globally removes that prefix from the patch content to meet pnpm's expected format

Batch vs Single-File Processing

Directory mode: enumerates all .patch files, then converts each (content + filename)
Single-file mode: validates existence, .patch extension, presence of + in name, and ensures the target converted file doesn't already exist; then converts
If a patch doesn't need conversion (no node_modules headers), it's skipped

For each converted file:

Key: filename without .patch, replace __ back to /, e.g. <name>/<sub>/...@<version>
Value: <patchesDir>/<convertedFileName> where patchesDir is the directory name containing the patches (e.g., patches)
Merges these into existing patchedDependencies, overwriting duplicate keys

Prefers pnpm-workspace.yaml: reads top-level patchedDependencies, merges new entries, and writes back
Fallback to package.json: updates pnpm.patchedDependencies in place if workspace file is absent
Merge strategy: additive with overwrite, preserving unrelated fields

File: patches/@react-spring+core+9.4.5.patch

diff

File: patches/@react-spring__core@9.4.5.patch

diff

Configuration in pnpm-workspace.yaml:

yaml

Directory mode: errors on non-existent path or non-directory
Single-file mode: blocks if the converted target file already exists (to avoid overwrite)
Requires filenames containing + and ending with .patch; otherwise errors
Normalizes Windows path separators to / where relevant (regex and key generation)