Merge pull request #7686 from maxim-belkin/test_ruby_update

utils/ruby.sh: update `test-ruby` (and rename to test_ruby)

Library/Homebrew/utils/ruby.sh

-test-ruby () {
-  [[ ! -x $1 ]] && { echo "false"; return 1; }
+test_ruby () {
+  if [[ ! -x $1 ]]
+  then
+    return 1
+  fi
+
   "$1" --enable-frozen-string-literal --disable=gems,did_you_mean,rubyopt -rrubygems -e \
-    "puts Gem::Version.new(RUBY_VERSION.to_s.dup).to_s.split('.').first(2) == \
-          Gem::Version.new('$required_ruby_version').to_s.split('.').first(2)" 2>/dev/null
+    "abort if Gem::Version.new(RUBY_VERSION.to_s.dup).to_s.split('.').first(2) != \
+              Gem::Version.new('$required_ruby_version').to_s.split('.').first(2)" 2>/dev/null
 }
 
 setup-ruby-path() {
@@ -10,7 +14,7 @@ setup-ruby-path() {
   local vendor_ruby_path
   local vendor_ruby_latest_version
   local vendor_ruby_current_version
-  local usable_ruby_version
+  local usable_ruby
   # When bumping check if HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH (in brew.sh)
   # also needs to be changed.
   local required_ruby_version="2.6"
@@ -60,7 +64,7 @@ If there's no Homebrew Portable Ruby available for your processor:
       IFS=$'\n' # Do word splitting on new lines only
       for ruby_exec in $(which -a ruby) $(PATH=$HOMEBREW_PATH which -a ruby)
       do
-        if [[ $(test-ruby "$ruby_exec") == "true" ]]; then
+        if test_ruby "$ruby_exec"; then
           HOMEBREW_RUBY_PATH=$ruby_exec
           break
         fi
@@ -71,13 +75,13 @@ If there's no Homebrew Portable Ruby available for your processor:
 
     if [[ -n "$HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH" ]]
     then
-      usable_ruby_version="true"
-    elif [[ -n "$HOMEBREW_RUBY_PATH" && -z "$HOMEBREW_FORCE_VENDOR_RUBY" ]]
+      usable_ruby=true
+    elif [[ -n "$HOMEBREW_RUBY_PATH" && -z "$HOMEBREW_FORCE_VENDOR_RUBY" ]] && test_ruby "$HOMEBREW_RUBY_PATH"
     then
-      usable_ruby_version=$(test-ruby "$HOMEBREW_RUBY_PATH")
+      usable_ruby=true
     fi
 
-    if [[ -z "$HOMEBREW_RUBY_PATH" || -n "$HOMEBREW_FORCE_VENDOR_RUBY" || "$usable_ruby_version" != "true" ]]
+    if [[ -z "$HOMEBREW_RUBY_PATH" || -n "$HOMEBREW_FORCE_VENDOR_RUBY" || -z $usable_ruby ]]
     then
       brew vendor-install ruby
       if [[ ! -x "$vendor_ruby_path" ]]