feat: add configuration for plugin to run go package

internal/cmd/generate.go

@@ -349,6 +349,7 @@ func codegen(ctx context.Context, combo config.CombinedSettings, sql OutputPair,
 		switch {
 		case plug.Process != nil:
 			handler = &process.Runner{
+				GoPkg:  plug.Process.GoPkg,
 				Cmd:    plug.Process.Cmd,
 				Env:    plug.Env,
 				Format: plug.Process.Format,

internal/config/config.go

@@ -89,6 +89,7 @@ type Plugin struct {
 	Name    string   `json:"name" yaml:"name"`
 	Env     []string `json:"env" yaml:"env"`
 	Process *struct {
+		GoPkg  string `json:"go_package" yaml:"go_package"`
 		Cmd    string `json:"cmd" yaml:"cmd"`
 		Format string `json:"format" yaml:"format"`
 	} `json:"process" yaml:"process"`

internal/ext/process/gen.go

@@ -19,6 +19,7 @@ import (
 )
 
 type Runner struct {
+	GoPkg  string
 	Cmd    string
 	Format string
 	Env    []string
@@ -53,13 +54,27 @@ func (r *Runner) Invoke(ctx context.Context, method string, args any, reply any,
 		return fmt.Errorf("unknown plugin format: %s", r.Format)
 	}
 
-	// Check if the output plugin exists
-	path, err := exec.LookPath(r.Cmd)
-	if err != nil {
-		return fmt.Errorf("process: %s not found", r.Cmd)
+	var cmd *exec.Cmd
+	switch {
+	case r.Cmd != "" && r.GoPkg == "":
+		// Check if the output plugin exists
+		path, err := exec.LookPath(r.Cmd)
+		if err != nil {
+			return fmt.Errorf("process: %s not found", r.Cmd)
+		}
+		cmd = exec.CommandContext(ctx, path, method)
+	case r.Cmd == "" && r.GoPkg != "":
+		// Check if the go binary exists
+		path, err := exec.LookPath("go")
+		if err != nil {
+			return fmt.Errorf("go binary required to run go package %s", r.GoPkg)
+		}
+		cmd = exec.CommandContext(ctx, path, method)
+		cmd.Args = []string{"run", r.GoPkg}
+	default:
+		return fmt.Errorf("cmd and go_package cannot both be empty for process plugin")
 	}
 
-	cmd := exec.CommandContext(ctx, path, method)
 	cmd.Stdin = bytes.NewReader(stdin)
 	cmd.Env = []string{
 		fmt.Sprintf("SQLC_VERSION=%s", info.Version),