dotenv: add agree-once improvement to confirmation prompt (#8729)

* dotenv: add possibility to agree once for a given .env file

* refactor: fix code style

* Use :A modifier instead of readlink. Thanks Aloxaf

* Use grep and clean up allowed list check logic

* Simplify and reorder file; change default allowed list path

* Add new feature to README

* Make sure ZSH_CACHE_DIR is defined

* Resolve symlinks in $PWD before storing in allowed list

Co-authored-by: Aloxaf <bailong104@gmail.com>
Co-authored-by: Marc Cornellà <marc.cornella@live.com>

plugins/dotenv/dotenv.plugin.zsh

@@ -1,35 +1,46 @@
+## Settings
+
+# Filename of the dotenv file to look for
+: ${ZSH_DOTENV_FILE:=.env}
+
+# Path to the file containing allowed paths
+: ${ZSH_DOTENV_ALLOWED_LIST:="${ZSH_CACHE_DIR:-$ZSH/cache}/dotenv-allowed.list"}
+
+
+## Functions
+
 source_env() {
   if [[ -f $ZSH_DOTENV_FILE ]]; then
-    if [ "$ZSH_DOTENV_PROMPT" != "false" ]; then
-      # confirm before sourcing file
-      local confirmation
-      # print same-line prompt and output newline character if necessary
-      echo -n "dotenv: source '$ZSH_DOTENV_FILE' file in the directory? (Y/n) "
-      read -k 1 confirmation; [[ "$confirmation" != $'\n' ]] && echo
-      # only bail out if confirmation character is n
-      if [[ "$confirmation" = [nN] ]]; then
-        return
+    if [[ "$ZSH_DOTENV_PROMPT" != false ]]; then
+      local confirmation dirpath="${PWD:A}"
+
+      # make sure there is an allowed file
+      touch "$ZSH_DOTENV_ALLOWED_LIST"
+
+      # check if current directory's .env file is allowed or ask for confirmation
+      if ! grep -q "$dirpath" "$ZSH_DOTENV_ALLOWED_LIST" &>/dev/null; then
+        # print same-line prompt and output newline character if necessary
+        echo -n "dotenv: found '$ZSH_DOTENV_FILE' file. Source it? ([Y]es/[n]o/[a]lways) "
+        read -k 1 confirmation; [[ "$confirmation" != $'\n' ]] && echo
+
+        # check input
+        case "$confirmation" in
+          [nN]) return ;;
+          [aA]) echo "$dirpath" >> "$ZSH_DOTENV_ALLOWED_LIST" ;;
+          *) ;; # interpret anything else as a yes
+        esac
       fi
     fi
 
     # test .env syntax
     zsh -fn $ZSH_DOTENV_FILE || echo "dotenv: error when sourcing '$ZSH_DOTENV_FILE' file" >&2
 
-    if [[ -o a ]]; then
-      source $ZSH_DOTENV_FILE
-    else
-      set -a
-      source $ZSH_DOTENV_FILE
-      set +a
-    fi
+    setopt localoptions allexport
+    source $ZSH_DOTENV_FILE
   fi
 }
 
 autoload -U add-zsh-hook
 add-zsh-hook chpwd source_env
 
-if [[ -z $ZSH_DOTENV_FILE ]]; then
-    ZSH_DOTENV_FILE=.env
-fi
-
 source_env