feat-dev: auto-npm i with branches

\### Rationale
Lower change for flaws and weird errors with old dependencies or
missing dependencies after a change of branch.

Author: codejedi365

.husky/post-checkout

@@ -0,0 +1,33 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+LOG_PREFIX="[.husky/post-checkout]"
+
+. "$(dirname "$0")/hook-utils.sh"
+
+HEAD_PREV="$1"
+HEAD_NEW="$2"
+CKOUT_TYPE_FLAG="$3"      # 0 = retrieve file from index, 1 = changing branches
+
+# check if this is a post-checkout after a `git clone`
+IS_CLONING=$( [ -z "$HEAD_PREV" ] && echo true || echo false )
+
+update_npm_dependencies() {
+  # Only run if chaning branches and not performing the initial `git clone`
+  if [ $CKOUT_TYPE_FLAG == 1 ] && [ $IS_CLONING == false ]; then
+    local changed_files=""
+    # derived from https://gist.github.com/taurus227/28960de89e6c43bb3d492125368f1224
+    changed_files="$(git diff-tree -r --name-only --no-commit-id $HEAD_PREV $HEAD_NEW)"
+
+    if echo "$changed_files" | grep --quiet "package-lock.json"; then
+      log "CHANGE DETECTED: 'package-lock.json'"
+      log "Dependency requirements changed! This will take a few seconds..."
+
+      local cmd="npm install --prefer-offline"
+      log "$> $cmd"
+      eval "$cmd"
+    fi
+  fi
+}
+
+update_npm_dependencies

.husky/post-merge

@@ -0,0 +1,56 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+[ -z "$LOG_PREFIX" ] && LOG_PREFIX="[.husky/post-merge]"
+
+. "$(dirname "$0")/hook-utils.sh"
+
+update_npm_dependencies() {
+  # derived from https://gist.github.com/taurus227/28960de89e6c43bb3d492125368f1224
+  local changed_files=""
+  changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)"
+
+  local NEEDS_INSTALL=true
+
+  if echo -e "$changed_files" | grep --quiet "package-lock.json"; then
+    log "CHANGE DETECTED: 'package-lock.json'"
+    log "Lock files rarely merge properly. Deleting and re-generating it..."
+
+    local output="$changed_files"
+    output="$(echo -e "$output" | grep "package-lock.json")"
+    local lockfiles=("$output")            # make array of filepaths
+    rm ${lockfiles[@]}
+
+  elif echo -e "$changed_files" | grep --quiet "package.json"; then
+    log "CHANGE DETECTED: 'package.json'"
+    log "Dependencies might of changed, lets make sure we are g2g!"
+  else
+    NEEDS_INSTALL=false
+  fi
+
+  if [ "$NEEDS_INSTALL" == true ]; then
+    cmd="npm install"
+    log "$> $cmd"
+    eval "$cmd"
+
+    changed_files="$(git diff --name-only --diff-filter=d)"
+    if echo -e "$changed_files" | grep --quiet "package-lock.json"; then
+      log "ALL FIXED! package-lock.json needed a refresh."
+
+      local lockfiles=($(echo -e "$changed_files" | grep "package-lock.json"))
+      git add -- "${lockfiles[@]}"
+      
+      for lockfile in "${lockfiles[@]}"; do
+        log "STAGED: $lockfile"
+      done
+      
+      local filenoun="file"
+      if [ "${#lockfiles[@]}" -gt 1 ]; then
+        filenoun="${filenoun}s"
+      fi
+      log "Please commit the newly generated $filenoun for the team!"
+    fi
+  fi
+}
+
+update_npm_dependencies

.husky/post-rewrite

@@ -0,0 +1,13 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+CALLER_CMD="$1"                            # rebase || amend
+export LOG_PREFIX="[.husky/post-rewrite]"
+
+. "$(dirname "$0")/hook-utils.sh"
+
+# derived from https://gist.github.com/taurus227/28960de89e6c43bb3d492125368f1224
+if [ "$CALLER_CMD" == "rebase" ]; then
+  log "DETECTED: git-rebase.";
+  $(dirname "$0")/post-merge
+fi