Chore: Move identity and errutil to apimachinery module (#89116)

pkg/apimachinery/errutil/template_test.go

@@ -0,0 +1,73 @@
+package errutil_test
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/grafana/grafana/pkg/apimachinery/errutil"
+)
+
+func TestTemplate(t *testing.T) {
+	tmpl := errutil.Internal("template.sampleError").MustTemplate("[{{ .Public.user }}] got error: {{ .Error }}")
+	err := tmpl.Build(errutil.TemplateData{
+		Public: map[string]any{
+			"user": "grot the bot",
+		},
+		Error: errors.New("oh noes"),
+	})
+
+	t.Run("Built error should return true when compared with templated error ", func(t *testing.T) {
+		require.True(t, errors.Is(err, tmpl))
+	})
+
+	t.Run("Built error should return true when compared with templated error base ", func(t *testing.T) {
+		require.True(t, errors.Is(err, tmpl.Base))
+	})
+}
+
+func ExampleTemplate() {
+	// Initialization, this is typically done on a package or global
+	// level.
+	var tmpl = errutil.Internal("template.sampleError").MustTemplate("[{{ .Public.user }}] got error: {{ .Error }}")
+
+	// Construct an error based on the template.
+	err := tmpl.Build(errutil.TemplateData{
+		Public: map[string]any{
+			"user": "grot the bot",
+		},
+		Error: errors.New("oh noes"),
+	})
+
+	fmt.Println(err.Error())
+
+	// Output:
+	// [template.sampleError] [grot the bot] got error: oh noes
+}
+
+func ExampleTemplate_public() {
+	// Initialization, this is typically done on a package or global
+	// level.
+	var tmpl = errutil.Internal("template.sampleError").MustTemplate(
+		"[{{ .Public.user }}] got error: {{ .Error }}",
+		errutil.WithPublic("Oh, no, error for {{ .Public.user }}"),
+	)
+
+	// Construct an error based on the template.
+	//nolint:errorlint
+	err := tmpl.Build(errutil.TemplateData{
+		Public: map[string]any{
+			"user": "grot the bot",
+		},
+		Error: errors.New("oh noes"),
+	}).(errutil.Error)
+
+	fmt.Println(err.Error())
+	fmt.Println(err.PublicMessage)
+
+	// Output:
+	// [template.sampleError] [grot the bot] got error: oh noes
+	// Oh, no, error for grot the bot
+}