brew.sh: new HOMEBREW_RUBY_PATH resolution logic

* Use vendor Ruby if it's present
* Install vendor Ruby for system without Ruby 2.x

2 files changed, 62 insertions, 20 deletions

diff --git a/Library/Homebrew/utils/ruby.sh b/Library/Homebrew/utils/ruby.sh
new file mode 100644
index 000000000..4b8e58f01
--- /dev/null
+++ b/Library/Homebrew/utils/ruby.sh
@@ -0,0 +1,57 @@
+setup-ruby-path() {
+  local vendor_dir
+  local vendor_ruby_current_version
+  local vendor_ruby_path
+  local ruby_version_major
+
+  vendor_dir="$HOMEBREW_LIBRARY/Homebrew/vendor"
+  vendor_ruby_current_version="$vendor_dir/portable-ruby/current"
+  vendor_ruby_path="$vendor_ruby_current_version/bin/ruby"
+
+  if [[ -z "$HOMEBREW_DEVELOPER" ]]
+  then
+    unset HOMEBREW_RUBY_PATH
+  fi
+
+  if [[ -z "$HOMEBREW_RUBY_PATH" && "$HOMEBREW_COMMAND" != "vendor-install" ]]
+  then
+    if [[ -x "$vendor_ruby_path" ]]
+    then
+      HOMEBREW_RUBY_PATH="$vendor_ruby_path"
+
+      if [[ $(readlink "$vendor_ruby_current_version") != "$(<"$vendor_dir/portable-ruby-version")" ]]
+      then
+        if ! brew vendor-install ruby --quiet
+        then
+          onoe "Failed to upgrade vendor Ruby."
+        fi
+      fi
+    else
+      if [[ -n "$HOMEBREW_OSX" ]]
+      then
+        HOMEBREW_RUBY_PATH="/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby"
+      else
+        HOMEBREW_RUBY_PATH="$(which ruby)"
+      fi
+
+      if [[ -n "$HOMEBREW_RUBY_PATH" ]]
+      then
+        ruby_version_major="$("$HOMEBREW_RUBY_PATH" --version)"
+        ruby_version_major="${ruby_version_major#ruby }"
+        ruby_version_major="${ruby_version_major%%.*}"
+      fi
+
+      if [[ "$ruby_version_major" != "2" ]]
+      then
+        brew vendor-install ruby --quiet
+        if [[ ! -x "$vendor_ruby_path" ]]
+        then
+          odie "Failed to install vendor Ruby."
+        fi
+        HOMEBREW_RUBY_PATH="$vendor_ruby_path"
+      fi
+    fi
+  fi
+
+  export HOMEBREW_RUBY_PATH
+}
diff --git a/Library/brew.sh b/Library/brew.sh
index c1606a4ff..3e137323c 100644
--- a/Library/brew.sh
+++ b/Library/brew.sh
@@ -64,31 +64,12 @@ fi
 unset GEM_HOME
 unset GEM_PATH
 
-if [[ -z "$HOMEBREW_DEVELOPER" ]]
-then
-  unset HOMEBREW_RUBY_PATH
-fi
-
 HOMEBREW_SYSTEM="$(uname -s)"
 case "$HOMEBREW_SYSTEM" in
   Darwin) HOMEBREW_OSX="1";;
   Linux) HOMEBREW_LINUX="1";;
 esac
 
-if [[ -z "$HOMEBREW_RUBY_PATH" ]]
-then
-  if [[ -n "$HOMEBREW_OSX" ]]
-  then
-    HOMEBREW_RUBY_PATH="/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby"
-  else
-    HOMEBREW_RUBY_PATH="$(which ruby)"
-    if [[ -z "$HOMEBREW_RUBY_PATH" ]]
-    then
-      odie "No Ruby found, cannot proceed."
-    fi
-  fi
-fi
-
 HOMEBREW_CURL="/usr/bin/curl"
 if [[ -n "$HOMEBREW_OSX" ]]
 then
@@ -131,7 +112,6 @@ export HOMEBREW_LIBRARY
 export HOMEBREW_VERSION
 export HOMEBREW_CACHE
 export HOMEBREW_CELLAR
-export HOMEBREW_RUBY_PATH
 export HOMEBREW_SYSTEM
 export HOMEBREW_CURL
 export HOMEBREW_PROCESSOR
@@ -231,6 +211,11 @@ fi
 
 # Hide shellcheck complaint:
 # shellcheck source=/dev/null
+source "$HOMEBREW_LIBRARY/Homebrew/utils/ruby.sh"
+setup-ruby-path
+
+# Hide shellcheck complaint:
+# shellcheck source=/dev/null
 source "$HOMEBREW_LIBRARY/Homebrew/utils/analytics.sh"
 setup-analytics
 report-analytics-screenview-command