Codegen: format golang code from cue (#105352)

pkg/codegen/go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/grafana/cog v0.0.28
 	github.com/grafana/cuetsy v0.1.11
 	github.com/matryer/is v1.4.1
+	golang.org/x/tools v0.32.0
 )
 
 require (
@@ -48,7 +49,6 @@ require (
 	golang.org/x/net v0.39.0 // indirect
 	golang.org/x/sync v0.13.0 // indirect
 	golang.org/x/text v0.24.0 // indirect
-	golang.org/x/tools v0.32.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 

pkg/codegen/jenny_gofmt.go

@@ -0,0 +1,29 @@
+package codegen
+
+import (
+	"go/format"
+	"path/filepath"
+
+	"golang.org/x/tools/imports"
+
+	"github.com/grafana/codejen"
+)
+
+// GoFormat applies go format to each go file
+func GoFormat() codejen.FileMapper {
+	return func(f codejen.File) (codejen.File, error) {
+		if filepath.Ext(f.RelativePath) != ".go" {
+			return f, nil
+		}
+
+		formatted, err := format.Source(f.Data)
+		if err != nil {
+			return f, err
+		}
+
+		f.Data, err = imports.Process("", formatted, &imports.Options{
+			Comments: true,
+		})
+		return f, err
+	}
+}