Skip TNS-alias path for service-name and SID syntax databases

When TNS_ADMIN is set, databases starting with `/` or `:` should use
the normal service-name/SID URL format instead of the TNS-alias path.
Replace allow(ENV).to receive stubs with actual ENV unset/restore.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

lib/plsql/jdbc_connection.rb

@@ -54,7 +54,7 @@ def self.create_raw(params)
 
     def self.jdbc_connection_url(params)
       database = params[:database]
-      if ENV["TNS_ADMIN"] && database && !params[:host] && !params[:url]
+      if ENV["TNS_ADMIN"] && database && database !~ %r{\A[:/]} && !params[:host] && !params[:url]
         "jdbc:oracle:thin:@#{database}"
       else
         return params[:url] if params[:url]

spec/plsql/connection_spec.rb

@@ -474,8 +474,13 @@
     end
 
     it "should use default host and port when not specified" do
-      url = PLSQL::JDBCConnection.jdbc_connection_url(database: "/MYSERVICENAME")
-      expect(url).to eq "jdbc:oracle:thin:@//localhost:1521/MYSERVICENAME"
+      original_tns_admin = ENV.delete("TNS_ADMIN")
+      begin
+        url = PLSQL::JDBCConnection.jdbc_connection_url(database: "/MYSERVICENAME")
+        expect(url).to eq "jdbc:oracle:thin:@//localhost:1521/MYSERVICENAME"
+      ensure
+        ENV["TNS_ADMIN"] = original_tns_admin
+      end
     end
 
     it "should use SID syntax when database starts with colon" do
@@ -489,10 +494,36 @@
     end
 
     it "should use TNS alias when TNS_ADMIN is set and no host specified" do
-      allow(ENV).to receive(:[]).and_call_original
-      allow(ENV).to receive(:[]).with("TNS_ADMIN").and_return("/path/to/tns")
-      url = PLSQL::JDBCConnection.jdbc_connection_url(database: "MYALIAS")
-      expect(url).to eq "jdbc:oracle:thin:@MYALIAS"
+      original_tns_admin = ENV["TNS_ADMIN"]
+      ENV["TNS_ADMIN"] = "/path/to/tns"
+      begin
+        url = PLSQL::JDBCConnection.jdbc_connection_url(database: "MYALIAS")
+        expect(url).to eq "jdbc:oracle:thin:@MYALIAS"
+      ensure
+        ENV["TNS_ADMIN"] = original_tns_admin
+      end
+    end
+
+    it "should use service name syntax when TNS_ADMIN is set and database starts with slash" do
+      original_tns_admin = ENV["TNS_ADMIN"]
+      ENV["TNS_ADMIN"] = "/path/to/tns"
+      begin
+        url = PLSQL::JDBCConnection.jdbc_connection_url(database: "/MYSERVICENAME")
+        expect(url).to eq "jdbc:oracle:thin:@//localhost:1521/MYSERVICENAME"
+      ensure
+        ENV["TNS_ADMIN"] = original_tns_admin
+      end
+    end
+
+    it "should use SID syntax when TNS_ADMIN is set and database starts with colon" do
+      original_tns_admin = ENV["TNS_ADMIN"]
+      ENV["TNS_ADMIN"] = "/path/to/tns"
+      begin
+        url = PLSQL::JDBCConnection.jdbc_connection_url(database: ":MYSID")
+        expect(url).to eq "jdbc:oracle:thin:@localhost:1521:MYSID"
+      ensure
+        ENV["TNS_ADMIN"] = original_tns_admin
+      end
     end
 
     it "should use custom URL when provided" do