Add ., ./lib, ./plugin directories to path for Python plugins

Author: Yusyuriv

Flow.Launcher.Core/Plugin/PythonPlugin.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 using System.IO;
 using System.Text.Json;
 using System.Threading;
@@ -29,10 +30,6 @@ public PythonPlugin(string filename)
             _startInfo.EnvironmentVariables["FLOW_VERSION"] = Constant.Version;
             _startInfo.EnvironmentVariables["FLOW_PROGRAM_DIRECTORY"] = Constant.ProgramDirectory;
             _startInfo.EnvironmentVariables["FLOW_APPLICATION_DIRECTORY"] = Constant.ApplicationDirectory;
-
-
-            //Add -B flag to tell python don't write .py[co] files. Because .pyc contains location infos which will prevent python portable
-            _startInfo.ArgumentList.Add("-B");
         }
 
         protected override Task<Stream> RequestAsync(JsonRPCRequestModel request, CancellationToken token = default)
@@ -50,10 +47,51 @@ protected override string Request(JsonRPCRequestModel rpcRequest, CancellationTo
             // TODO: Async Action
             return Execute(_startInfo);
         }
+
         public override async Task InitAsync(PluginInitContext context)
         {
-            _startInfo.ArgumentList.Add(context.CurrentPluginMetadata.ExecuteFilePath);
-            _startInfo.ArgumentList.Add("");
+            // Run .py files via `-c <code>`
+            if (context.CurrentPluginMetadata.ExecuteFilePath.EndsWith(".py", StringComparison.OrdinalIgnoreCase))
+            {
+                var rootDirectory = context.CurrentPluginMetadata.PluginDirectory;
+                var libDirectory = Path.Combine(rootDirectory, "lib");
+                var pluginDirectory = Path.Combine(rootDirectory, "plugin");
+
+                // This makes it easier for plugin authors to import their own modules.
+                // They won't have to add `.`, `./lib`, or `./plugin` to their sys.path manually.
+                // Instead of running the .py file directly, we pass the code we want to run as a CLI argument.
+                // This code sets sys.path for the plugin author and then runs the .py file via runpy.
+                _startInfo.ArgumentList.Add("-c");
+                _startInfo.ArgumentList.Add(
+                    $"""
+                     import sys
+                     sys.path.append(r'{rootDirectory}')
+                     sys.path.append(r'{libDirectory}')
+                     sys.path.append(r'{pluginDirectory}')
+
+                     import runpy
+                     runpy.run_path(r'{context.CurrentPluginMetadata.ExecuteFilePath}', None, '__main__')
+                     """
+                );
+                // Plugins always expect the JSON data to be in the third argument
+                // (we're always setting it as _startInfo.ArgumentList[2] = ...).
+                _startInfo.ArgumentList.Add("");
+                // Because plugins always expect the JSON data to be in the third argument, and specifying -c <code>
+                // takes up two arguments, we have to move `-B` to the end.
+                _startInfo.ArgumentList.Add("-B");
+            }
+            // Run .pyz files as is
+            else
+            {
+                // -B flag is needed to tell python not to write .py[co] files.
+                // Because .pyc contains location infos which will prevent python portable
+                _startInfo.ArgumentList.Add("-B");
+                _startInfo.ArgumentList.Add(context.CurrentPluginMetadata.ExecuteFilePath);
+                // Plugins always expect the JSON data to be in the third argument
+                // (we're always setting it as _startInfo.ArgumentList[2] = ...).
+                _startInfo.ArgumentList.Add("");
+            }
+
             await base.InitAsync(context);
             _startInfo.WorkingDirectory = context.CurrentPluginMetadata.PluginDirectory;
         }

Flow.Launcher.Core/Plugin/PythonPluginV2.cs

@@ -33,7 +33,36 @@ public PythonPluginV2(string filename)
 
         public override async Task InitAsync(PluginInitContext context)
         {
-            StartInfo.ArgumentList.Add(context.CurrentPluginMetadata.ExecuteFilePath);
+            // Run .py files via `-c <code>`
+            if (context.CurrentPluginMetadata.ExecuteFilePath.EndsWith(".py", StringComparison.OrdinalIgnoreCase))
+            {
+                var rootDirectory = context.CurrentPluginMetadata.PluginDirectory;
+                var libDirectory = Path.Combine(rootDirectory, "lib");
+                var pluginDirectory = Path.Combine(rootDirectory, "plugin");
+                var filePath = context.CurrentPluginMetadata.ExecuteFilePath;
+
+                // This makes it easier for plugin authors to import their own modules.
+                // They won't have to add `.`, `./lib`, or `./plugin` to their sys.path manually.
+                // Instead of running the .py file directly, we pass the code we want to run as a CLI argument.
+                // This code sets sys.path for the plugin author and then runs the .py file via runpy.
+                StartInfo.ArgumentList.Add("-c");
+                StartInfo.ArgumentList.Add(
+                    $"""
+                     import sys
+                     sys.path.append(r'{rootDirectory}')
+                     sys.path.append(r'{libDirectory}')
+                     sys.path.append(r'{pluginDirectory}')
+                     
+                     import runpy
+                     runpy.run_path(r'{filePath}', None, '__main__')
+                     """
+                );
+            }
+            // Run .pyz files as is
+            else
+            {
+                StartInfo.ArgumentList.Add(context.CurrentPluginMetadata.ExecuteFilePath);
+            }
             await base.InitAsync(context);
         }