Ⓜ️ Add init subcommand

Author: jsnjack

cmd/cmd_init.go

@@ -0,0 +1,72 @@
+/*
+Copyright © 2024 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+// initCmd represents the init command
+var initCmd = &cobra.Command{
+	Use:   "init",
+	Short: "initialize a virtual environment in the current directory",
+	Long: `Initialize a virtual environment in the current directory in .venv directory.
+If requirements.txt or similar file is present, it will automatically
+install the dependenciesfrom it.`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		cmd.SilenceUsage = true
+
+		deleteOldEnvFlag, err := cmd.Flags().GetBool("new-environment")
+		if err != nil {
+			return err
+		}
+
+		requirementsFileFlag, err := cmd.Flags().GetString("requirements-file")
+		if err != nil {
+			return err
+		}
+
+		pythonFlag, err := cmd.Flags().GetString("python")
+		if err != nil {
+			return err
+		}
+
+		printProgress("Gathering information about script and environment...")
+		script, err := NewInitCmd(pythonFlag, requirementsFileFlag)
+		if err != nil {
+			return err
+		}
+
+		printProgress("Ensuring virtual environment...")
+		err = script.EnsureEnv(deleteOldEnvFlag)
+		if err != nil {
+			return err
+		}
+
+		printProgress("Done!")
+		if !flagDebug {
+			// Clear all progress messages
+			printProgress("")
+		}
+
+		// Flush the buffers to preserve the output order and avoid interference
+		// between the script output and the invenv output
+		os.Stderr.Sync()
+		os.Stdout.Sync()
+		return nil
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(initCmd)
+	initCmd.Flags().StringP("requirements-file", "r", "",
+		`use specified requirements file. If not provided, it
+will try to guess the requirements file name:
+requirements_<script_name>.txt, <script_name>_requirements.txt or
+requirements.txt`)
+	initCmd.Flags().BoolP("new-environment", "n", false, "create a new virtual environment even if it already exists")
+	initCmd.Flags().StringP("python", "p", "", "use specified Python interpreter")
+}

cmd/script.go

@@ -240,3 +240,82 @@ func NewScript(scriptName string, interpreterOverride string, requirementsOverri
 	}
 	return script, nil
 }
+
+// NewInitCmd creates a new Script instance
+func NewInitCmd(interpreterOverride string, requirementsOverride string) (*Script, error) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return nil, err
+	}
+
+	// Try to find requirements.txt file for the script
+	requirementsFile, err := getRequirementsFileForScript(path.Join(cwd, ".placeholder"), requirementsOverride)
+	if err != nil {
+		return nil, err
+	}
+
+	if flagDebug {
+		if requirementsFile == "" {
+			loggerErr.Println("No requirements file found")
+		} else {
+			loggerErr.Println("Found requirements file: ", requirementsFile)
+		}
+	}
+
+	requirementsHash := ""
+	if requirementsFile != "" {
+		requirementsHash, err = getFileHash(requirementsFile)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if flagDebug {
+		loggerErr.Printf("Requirements file hash: %s\n", requirementsHash)
+	}
+
+	var pythonInterpreter string
+	if interpreterOverride == "" {
+		pythonInterpreter = "python"
+	} else {
+		pythonInterpreter = interpreterOverride
+	}
+
+	// Check if the python interpreter exists in path
+	_, err = exec.LookPath(pythonInterpreter)
+	if err != nil && interpreterOverride != "" {
+		return nil, fmt.Errorf("failed to find python interpreter %s: %s", pythonInterpreter, err)
+	} else if err != nil {
+		if flagDebug {
+			loggerErr.Printf("Failed to find python interpreter %s: %s, assuming `python`...\n", pythonInterpreter, err)
+		}
+		pythonInterpreter = "python"
+		_, err = exec.LookPath(pythonInterpreter)
+		if err != nil {
+			return nil, fmt.Errorf("failed to find python interpreter %s: %s", pythonInterpreter, err)
+		}
+	}
+
+	pythonVersion, err := getPythonVersion(pythonInterpreter)
+	if err != nil {
+		return nil, err
+	}
+
+	if flagDebug {
+		loggerErr.Printf("Using python interpreter: %s\n", pythonVersion)
+	}
+
+	envDir := ".venv"
+
+	if flagDebug {
+		loggerErr.Println("Using virtual environment: ", envDir)
+	}
+
+	script := &Script{
+		AbsolutePath:      cwd,
+		EnvDir:            envDir,
+		PythonInterpreter: pythonInterpreter,
+		RequirementsPath:  requirementsFile,
+	}
+	return script, nil
+}