Add unit tests for custom errors

errors.go

@@ -8,7 +8,7 @@ type ErrTemplateNotFound struct {
 }
 
 func (e ErrTemplateNotFound) Error() string {
-	return fmt.Sprintf("template %s not found", e.Name)
+	return fmt.Sprintf("template '%s' not found", e.Name)
 }
 
 // ErrTemplateExecution is returned when a template fails to execute.
@@ -18,7 +18,7 @@ type ErrTemplateExecution struct {
 }
 
 func (e ErrTemplateExecution) Error() string {
-	return fmt.Sprintf("failed to execute template %s: %v", e.Name, e.Err)
+	return fmt.Sprintf("failed to execute template '%s': '%v'", e.Name, e.Err)
 }
 
 func (e ErrTemplateExecution) Unwrap() error {

errors_test.go

@@ -0,0 +1,29 @@
+package templator
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestErrTemplateNotFound_Error(t *testing.T) {
+	t.Parallel()
+
+	e := ErrTemplateNotFound{Name: "foo"}
+
+	got := e.Error()
+	assert.Equal(t, "template 'foo' not found", got)
+}
+
+func TestErrTemplateExecution_Error(t *testing.T) {
+	t.Parallel()
+
+	e := ErrTemplateExecution{
+		Name: "foo",
+		Err:  errors.New("bar"),
+	}
+
+	got := e.Error()
+	assert.Equal(t, "failed to execute template 'foo': 'bar'", got)
+}

template_validator_test.go

@@ -92,6 +92,8 @@ func Test_validateField(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
 			err := validateField(tc.typ, tc.fieldPath)
 
 			if tc.wantErr {