Allow underscores as valid characters in the project directory (#2281)

Per a discussion with Andrew (RC) and @matthewjchandler we should accept
underscores in the path.

Closes #2280

Author: hectorcorrea

app/models/project.rb

@@ -253,11 +253,6 @@ def project_directory_pathname
       end
     end
 
-    # Ensure that the project directory is a valid path
-    def safe_directory(directory)
-      Project.safe_directory(directory)
-    end
-
     def log_elapsed(start_time, prefix, message)
       elapsed_time = Time.zone.now - start_time
       timing_info = "#{format('%.2f', elapsed_time)} s"

app/models/project_metadata.rb

@@ -48,8 +48,8 @@ def self.default_provisionality
   def self.safe_directory(directory)
     return "" if directory.nil?
 
-    # only alphanumeric characters and /
-    directory.strip.gsub(/[^A-Za-z\d\/]/, "-")
+    # only alphanumeric characters, underscores, and /
+    directory.strip.gsub(/[^A-Za-z\d_\/]/, "-")
   end
 
   attr_accessor(

spec/models/project_metadata_spec.rb

@@ -117,4 +117,19 @@
       expect(project_metadata.title).to eq("title abc again")
     end
   end
+
+  describe "#safe_directory" do
+    it "handles nil values" do
+      expect(described_class.safe_directory(nil)).to eq ""
+    end
+
+    it "honors dashes and underscores" do
+      expect(described_class.safe_directory("abc_123")).to eq "abc_123"
+      expect(described_class.safe_directory("abc-456")).to eq "abc-456"
+    end
+
+    it "replaces unexpected characters with dashes" do
+      expect(described_class.safe_directory("hello#world{x}")).to eq "hello-world-x-"
+    end
+  end
 end