Robustify Git-Hooks for use with GitHub Desktop (#499)

git: try to make pre-push hook more robust with sourcing npm

.githooks/pre-push

@@ -2,9 +2,30 @@
 
 set -eu
 
-if ! [ -x "$(command -v npm)" ]; then
-  echo 'Error: npm not found. Make it available to the host shell (e.g., with "nvm use --lts").'
-  exit 2
+NPM_CMD="npm"
+
+if ! (type $NPM_CMD >> /dev/null); then
+  echo "npm not found, trying to make it available using nvm..."
+  if type nvm >> /dev/null; then
+    echo "nvm found, using it to install the latest lts node"
+    nvm use --lts
+  else
+    echo "nvm not found, trying to make it available using the nvm.sh"
+    # try to make it available based on https://github.com/typicode/husky/issues/912#issuecomment-817522060
+    export NVM_DIR="$HOME/.nvm/nvm.sh"
+    . "$(dirname $NVM_DIR)/nvm.sh"
+
+    export NVM_DIR="$HOME/.nvm"
+    a=$(nvm ls --no-colors | grep 'node')
+    v=$(echo "$a" | sed -E 's/.*\(-> ([^ ]+).*/\1/')
+
+    export PATH="$NVM_DIR/versions/node/$v/bin:$PATH"
+
+    if ! (type $NPM_CMD >> /dev/null); then
+      echo "no variant of npm or nvm found, trying to use the npm.cmd"
+      NPM_CMD="npm.cmd"
+    fi
+  fi
 fi
 
 
@@ -37,7 +58,7 @@ if [ -n "$(git status --porcelain)" ]; then
 fi
 
 echo "Linting project (local mode)..."
-npm run lint-local
+$NPM_CMD run lint-local
 
 
 # shellcheck disable=SC2124 # we want the argument splitting