refactor(i18n): add service option stringers

Co-Authored-By: Virgil <virgil@lethean.io>

core_service.go

@@ -53,6 +53,36 @@ type FSSource struct {
 	Dir string
 }
 
+// String returns a compact summary of the filesystem source.
+func (s FSSource) String() string {
+	if s.Dir == "" {
+		return core.Sprintf("FSSource{fs=%T}", s.FS)
+	}
+	return core.Sprintf("FSSource{fs=%T dir=%q}", s.FS, s.Dir)
+}
+
+// String returns a compact summary of the service options.
+func (o ServiceOptions) String() string {
+	extraFS := "[]"
+	if len(o.ExtraFS) > 0 {
+		parts := make([]string, len(o.ExtraFS))
+		for i, src := range o.ExtraFS {
+			parts[i] = src.String()
+		}
+		extraFS = "[" + core.Join(", ", parts...) + "]"
+	}
+	return core.Sprintf(
+		"ServiceOptions{language=%q fallback=%q formality=%s location=%q mode=%s debug=%t extraFS=%s}",
+		o.Language,
+		o.Fallback,
+		o.Formality,
+		o.Location,
+		o.Mode,
+		o.Debug,
+		extraFS,
+	)
+}
+
 // NewCoreService creates an i18n Core service factory.
 // Automatically loads locale filesystems from:
 // 1. Embedded go-i18n base translations (grammar, verbs, nouns)

core_service_test.go

@@ -2,6 +2,7 @@ package i18n
 
 import (
 	"testing"
+	"testing/fstest"
 
 	"dappco.re/go/core"
 	"github.com/stretchr/testify/assert"
@@ -75,3 +76,29 @@ func TestCoreServiceMissingKeysReturnsCopies(t *testing.T) {
 	require.Len(t, again, 1)
 	assert.Equal(t, "bar", again[0].Args["foo"])
 }
+
+func TestServiceOptionsAndFSSourceString(t *testing.T) {
+	opts := ServiceOptions{
+		Language:  "en-GB",
+		Fallback:  "en",
+		Formality: FormalityFormal,
+		Location:  "workspace",
+		Mode:      ModeCollect,
+		Debug:     true,
+		ExtraFS: []FSSource{
+			{FS: fstest.MapFS{}, Dir: "locales"},
+		},
+	}
+
+	got := opts.String()
+	assert.Contains(t, got, `language="en-GB"`)
+	assert.Contains(t, got, `fallback="en"`)
+	assert.Contains(t, got, `formality=formal`)
+	assert.Contains(t, got, `location="workspace"`)
+	assert.Contains(t, got, `mode=collect`)
+	assert.Contains(t, got, `debug=true`)
+	assert.Contains(t, got, `FSSource{fs=fstest.MapFS dir="locales"}`)
+
+	src := FSSource{FS: fstest.MapFS{}, Dir: "translations"}
+	assert.Equal(t, `FSSource{fs=fstest.MapFS dir="translations"}`, src.String())
+}