feat(updater): add support for terminal hyperlinks

tools/upgrade.sh

@@ -15,11 +15,98 @@ cd "$ZSH"
 # Use colors, but only if connected to a terminal
 # and that terminal supports them.
 
+# The [ -t 1 ] check only works when the function is not called from
+# a subshell (like in `$(...)` or `(...)`, so this hack redefines the
+# function at the top level to always return false when stdout is not
+# a tty.
+if [ -t 1 ]; then
+  is_tty() {
+    true
+  }
+else
+  is_tty() {
+    false
+  }
+fi
+
+# This function uses the logic from supports-hyperlinks[1][2], which is
+# made by Kat Marchán (@zkat) and licensed under the Apache License 2.0.
+# [1] https://github.com/zkat/supports-hyperlinks
+# [2] https://crates.io/crates/supports-hyperlinks
+#
+# Copyright (c) 2021 Kat Marchán
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+supports_hyperlinks() {
+  # $FORCE_HYPERLINK must be set and be non-zero (this acts as a logic bypass)
+  if [ -n "$FORCE_HYPERLINK" ]; then
+    [ "$FORCE_HYPERLINK" != 0 ]
+    return $?
+  fi
+
+  # If stdout is not a tty, it doesn't support hyperlinks
+  is_tty || return 1
+
+  # DomTerm terminal emulator (domterm.org)
+  if [ -n "$DOMTERM" ]; then
+    return 0
+  fi
+
+  # VTE-based terminals above v0.50 (Gnome Terminal, Guake, ROXTerm, etc)
+  if [ -n "$VTE_VERSION" ]; then
+    [ $VTE_VERSION -ge 5000 ]
+    return $?
+  fi
+
+  # If $TERM_PROGRAM is set, these terminals support hyperlinks
+  case "$TERM_PROGRAM" in
+  Hyper|iTerm.app|terminology|WezTerm) return 0 ;;
+  esac
+
+  # kitty supports hyperlinks
+  if [ "$TERM" = xterm-kitty ]; then
+    return 0
+  fi
+
+  # Windows Terminal or Konsole also support hyperlinks
+  if [ -n "$WT_SESSION" ] || [ -n "$KONSOLE_VERSION" ]; then
+    return 0
+  fi
+
+  return 1
+}
+
+fmt_link() {
+  # $1: text, $2: url, $3: fallback mode
+  if supports_hyperlinks; then
+    printf '\033]8;;%s\a%s\033]8;;\a\n' "$2" "$1"
+    return
+  fi
+
+  case "$3" in
+  --text) printf '%s\n' "$1" ;;
+  --url|*) fmt_underline "$2" ;;
+  esac
+}
+
+fmt_underline() {
+  is_tty && printf '\033[4m%s\033[24m\n' "$*" || printf '%s\n' "$*"
+}
+
 setopt typeset_silent
 typeset -a RAINBOW
-typeset RED GREEN YELLOW BLUE BOLD DIM UNDER RESET
 
-if [ -t 1 ]; then
+if is_tty; then
   RAINBOW=(
     "$(printf '\033[38;5;196m')"
     "$(printf '\033[38;5;202m')"
@@ -35,8 +122,6 @@ if [ -t 1 ]; then
   YELLOW=$(printf '\033[33m')
   BLUE=$(printf '\033[34m')
   BOLD=$(printf '\033[1m')
-  DIM=$(printf '\033[2m')
-  UNDER=$(printf '\033[4m')
   RESET=$(printf '\033[0m')
 fi
 
@@ -104,10 +189,10 @@ if git pull --rebase --stat $remote $branch; then
   printf '%s\____/%s_/ /_/ %s /_/ /_/ /_/%s\__, / %s   /___/%s____/%s_/ /_/  %s\n' $RAINBOW $RESET
   printf '%s    %s        %s           %s /____/ %s       %s     %s          %s\n' $RAINBOW $RESET
   printf '\n'
-  printf "${BLUE}%s${RESET}\n" "$message"
+  printf "${BLUE}%s${RESET}\n\n" "$message"
-  printf "${BLUE}${BOLD}%s ${UNDER}%s${RESET}\n" "To keep up with the latest news and updates, follow us on Twitter:" "https://twitter.com/ohmyzsh"
+  printf "${BLUE}${BOLD}%s %s${RESET}\n" "To keep up with the latest news and updates, follow us on Twitter:" "$(fmt_link @ohmyzsh https://twitter.com/ohmyzsh)"
-  printf "${BLUE}${BOLD}%s ${UNDER}%s${RESET}\n" "Want to get involved in the community? Join our Discord:" "https://discord.gg/ohmyzsh"
+  printf "${BLUE}${BOLD}%s %s${RESET}\n" "Want to get involved in the community? Join our Discord:" "$(fmt_link "Discord server" https://discord.gg/ohmyzsh)"
-  printf "${BLUE}${BOLD}%s ${UNDER}%s${RESET}\n" "Get your Oh My Zsh swag at:" "https://shop.planetargon.com/collections/oh-my-zsh"
+  printf "${BLUE}${BOLD}%s %s${RESET}\n" "Get your Oh My Zsh swag at:" "$(fmt_link "Planet Argon Shop" https://shop.planetargon.com/collections/oh-my-zsh)"
 else
   ret=$?
   printf "${RED}%s${RESET}\n" 'There was an error updating. Try again later?'