u3d/installer: support custom install paths through U3D_EXTRA_PATHS

lib/u3d/installer.rb

@@ -86,6 +86,21 @@ def installed_sorted_by_versions
       return [] if list.empty?
       list.sort { |a, b| UnityVersionComparator.new(a.version) <=> UnityVersionComparator.new(b.version) }
     end
+
+    protected
+
+    def extra_installation_paths
+      return [] if ENV['U3D_EXTRA_PATHS'].nil?
+      ENV['U3D_EXTRA_PATHS'].strip.split(File::PATH_SEPARATOR)
+    end
+
+    def find_installations_with_path(default_root_path: '', postfix: [])
+      ([default_root_path] | extra_installation_paths).map do |path|
+        UI.verbose "Looking for installed Unity version under #{path}"
+        pattern = File.join([path] + postfix)
+        Dir.glob(pattern).map { |found_path| yield found_path }
+      end.flatten
+    end
   end
 
   # deprecated
@@ -169,9 +184,14 @@ def uninstall(unity: nil)
     private
 
     def list_installed_paths
-      find = File.join(DEFAULT_MAC_INSTALL, 'Applications', 'Unity*', 'Unity.app')
-      paths = Dir[find]
-      paths = paths.map { |u| Pathname.new(u).parent.to_s }
+      paths = find_installations_with_path(
+        default_root_path: DEFAULT_MAC_INSTALL,
+        postfix: %w[
+          Applications
+          Unity*
+          Unity.app
+        ]
+      ) { |u| Pathname.new(u).parent.to_s }
       UI.verbose "Found list_installed_paths: #{paths}"
       paths
     end
@@ -332,17 +352,25 @@ def pkg_install_path(unity_root_path, pinfo_path)
     end
 
     def list_installed_paths
-      find = File.join(DEFAULT_LINUX_INSTALL, 'unity-editor-*', 'Editor')
-      paths = Dir[find]
-      paths = paths.map { |u| Pathname.new(u).parent.to_s }
+      paths = find_installations_with_path(
+        default_root_path: DEFAULT_LINUX_INSTALL,
+        postfix: %w[
+          unity-editor-*
+          Editor
+        ]
+      ) { |u| Pathname.new(u).parent.to_s }
       UI.verbose "Found list_installed_paths: #{paths}"
       paths
     end
 
     def debian_installed_paths
-      find = File.join(DEFAULT_LINUX_INSTALL, 'Unity', 'Editor')
-      paths = Dir[find]
-      paths = paths.map { |u| Pathname.new(u).parent.to_s }
+      paths = find_installations_with_path(
+        default_root_path: DEFAULT_LINUX_INSTALL,
+        postfix: %w[
+          Unity
+          Editor
+        ]
+      ) { |u| Pathname.new(u).parent.to_s }
       UI.verbose "Found debian_installed_paths: #{paths}"
       paths
     end
@@ -362,8 +390,14 @@ def sanitize_install(unity, long: false, dry_run: false)
     end
 
     def installed
-      find = File.join(DEFAULT_WINDOWS_INSTALL, 'Unity*', 'Editor', 'Uninstall.exe')
-      Dir[find].map { |path| WindowsInstallation.new(root_path: File.expand_path('../..', path)) }
+      find_installations_with_path(
+        default_root_path: DEFAULT_WINDOWS_INSTALL,
+        postfix: %w[
+          Unity*
+          Editor
+          Uninstall.exe
+        ]
+      ) { |path| WindowsInstallation.new(root_path: File.expand_path('../..', path)) }
     end
 
     def install(file_path, version, installation_path: nil, info: {})

spec/u3d/installer_spec.rb

@@ -180,8 +180,8 @@ class DummyInstaller < U3d::BaseInstaller
           u1 = linux_5_6_standard
           u2 = linux_5_6_debian
           u3 = linux_2017_1_weird
-          allow(Dir).to receive(:[]).with('/opt/unity-editor-*/Editor') { ["#{u1.root_path}/Editor", "#{u3.root_path}/Editor"] }
-          allow(Dir).to receive(:[]).with('/opt/Unity/Editor') { ["#{u2.root_path}/Editor"] }
+          allow(Dir).to receive(:glob).with('/opt/unity-editor-*/Editor') { ["#{u1.root_path}/Editor", "#{u3.root_path}/Editor"] }
+          allow(Dir).to receive(:glob).with('/opt/Unity/Editor') { ["#{u2.root_path}/Editor"] }
 
           allow(U3d::LinuxInstallation).to receive(:new).with(root_path: u1.root_path) { u1 }
           allow(U3d::LinuxInstallation).to receive(:new).with(root_path: u2.root_path) { u2 }