A shell script that forces symlinks to be created within a workspace (package) of an npm monorepo, so that `node_modules` in the repo root are referenced symbolically in the workspace's `node_modules`. This script can be run by the CI or a build script to forcefully ensure workspaces know about dependencies available in the repo root. It's a bi…

npm-symlink.sh

#!/usr/bin/env bash
# A script that forces a target npm workspace to symbolically link to any root node_modules that it does not explicitly contain
# Example usage: ./scripts/npm-symlink.sh packages/website

set -o errexit
set -o nounset
set -o pipefail

WORKSPACE="$1"

echo -e "\n 🛠️ Creating forceful NPM symlinks \n"

# Find repo root
PROJECT_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
WORKSPACE_DIR="${PROJECT_ROOT}/${WORKSPACE}"
WORKSPACE_NODE_MODULES="${WORKSPACE_DIR}/node_modules"
ROOT_NODE_MODULES="${PROJECT_ROOT}/node_modules"

mkdir -p "${WORKSPACE_NODE_MODULES}"

create_symlinks() {
    local package=$1
    local target_path=$2
    local root_path=$3

    # Scoped packages (@...) need their parent directory created
    local parent_dir
    parent_dir=$(dirname "${target_path}")
    mkdir -p "${parent_dir}"

    if [ ! -e "${target_path}" ]; then
        ln -s "${root_path}" "${target_path}"
        echo -e "✨ Created symlink for ${package} \n"
    else
        echo -e "⏩ Skipped ${package}, already exists."
    fi
}

# Loop through root node_modules
for module in ${ROOT_NODE_MODULES}/*; do
    module_name=$(basename "${module}")

    if [[ "${module_name}" == @* ]]; then
        # For scoped packages (@...)
        for sub_module in "${module}"/*; do
            sub_module_name=$(basename "${sub_module}")
            create_symlinks "${module_name}/${sub_module_name}" "${WORKSPACE_NODE_MODULES}/${module_name}/${sub_module_name}" "${sub_module}"
        done
    else
        # For non-scoped packages (most non-org packages)
        create_symlinks "${module_name}" "${WORKSPACE_NODE_MODULES}/${module_name}" "${module}"
    fi
done

echo -e "\n 😅 All symlinks created \n"