build: update homebrew workflow to address stylistic requirements (#449)

Signed-off-by: Ben Stickel <ben.stickel@elastic.co>

Author: fin09pcap

build/mage/release/formula.go

@@ -29,7 +29,7 @@ import (
 	"github.com/elastic/harp/build/artifact"
 )
 
-var formulaTemplate = strings.TrimSpace(`# typed: false
+var formulaTemplate = `# typed: false
 # frozen_string_literal: true
 
 # Code generated by Harp build tool
@@ -85,15 +85,14 @@ class {{ .Formula }} < Formula
         else
           bin.install "{{ .Bin }}-linux-arm-6" => "{{ .Bin }}"
         end
-      else
-        if Hardware::CPU.is_64_bit?
-          bin.install "{{ .Bin }}-linux-amd64-v1" => "{{ .Bin }}"
-        end
+      elsif Hardware::CPU.is_64_bit?
+        bin.install "{{ .Bin }}-linux-amd64-v1" => "{{ .Bin }}"
       end
     end
 
     # Exclude from Gatekeeper quarantine on macOS Catalina+
-    if OS.mac? && MacOS.version >= :catalina && /com.apple.quarantine/.match?(Utils.safe_popen_read("xattr", "#{bin}/{{ .Bin }}"))
+    quarantine_check = Utils.safe_popen_read("xattr", bin/"{{ .Bin }}")
+    if OS.mac? && MacOS.version >= :catalina && /com.apple.quarantine/.match?(quarantine_check)
       (bin/"{{ .Bin }}").chmod 0755
       begin
         system "xattr", "-d",
@@ -117,11 +116,11 @@ class {{ .Formula }} < Formula
   end
 
   test do
-    assert_predicate bin/"{{ .Bin }}", :exist?
+    assert_path_exists bin/"{{ .Bin }}"
     assert_match version.to_s, shell_output("#{bin}/{{ .Bin }} version")
   end
 end
-`)
+`
 
 type formulaModel struct {
 	Repository  string