fix: generate command fix and test

internal/shell/cmd_compile.go

@@ -36,15 +36,7 @@ func (c *CompileCommand) compile(compileCmd string, compileArgs ...string) error
 	if err != nil {
 		return merry.Wrap(err)
 	}
-	genInput := gen.Input{
-		Imports:     c.Imports.Value(),
-		Replaces:    c.Replaces.Value(),
-		Gets:        c.Gets.Value(),
-		WorkingDir:  workingDir,
-		USQLVersion: c.USQLVersion,
-		USQLModule:  c.USQLModule,
-	}
-	genResult, err := c.generator(genInput)
+	genResult, err := c.generate(workingDir)
 	if err != nil {
 		return merry.Wrap(err)
 	}
@@ -63,6 +55,18 @@ func (c *CompileCommand) compile(compileCmd string, compileArgs ...string) error
 	return run.GoBin(workingDir, c.goBin, args...)
 }
 
+func (c *CompileCommand) generate(workingDir string) (gen.Result, error) {
+	genInput := gen.Input{
+		Imports:     c.Imports.Value(),
+		Replaces:    c.Replaces.Value(),
+		Gets:        c.Gets.Value(),
+		WorkingDir:  workingDir,
+		USQLVersion: c.USQLVersion,
+		USQLModule:  c.USQLModule,
+	}
+	return c.generator(genInput)
+}
+
 func (c *CompileCommand) MakeFlags() []cli.Flag {
 	return append([]cli.Flag{
 		&cli.StringSliceFlag{

internal/shell/cmd_generate_test.go

@@ -0,0 +1,23 @@
+package shell
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGenerate(t *testing.T) {
+	tmpDir := t.TempDir()
+	t.Run("happy path", func(t *testing.T) {
+		cmd := GenerateCommand{
+			CompileCommand: minimalCompileCommand(),
+			output:         tmpDir,
+		}
+		err := cmd.Action(nil)
+		require.NoError(t, err)
+
+		require.FileExists(t, filepath.Join(tmpDir, "go.mod"))
+	})
+
+}

internal/shell/commands.go

@@ -3,6 +3,9 @@ package shell
 // Defines commands too short for their own file and the Commands object
 
 import (
+	"os"
+
+	"github.com/ansel1/merry/v2"
 	"github.com/urfave/cli/v2"
 )
 
@@ -33,7 +36,12 @@ if value is -, tar archive will be written to standard output`,
 }
 
 func (c *GenerateCommand) Action(*cli.Context) error {
-	return c.CompileCommand.compile("")
+	err := os.MkdirAll(c.output, 0700)
+	if err != nil {
+		return merry.Wrap(err)
+	}
+	_, err = c.generate(c.output)
+	return err
 }
 
 type Commands struct {