store default values during NewParser

1 files changed, 19 insertions, 8 deletions

diff --git a/usage_test.go b/usage_test.go
index fc0b8c5..d9d33f0 100644
--- a/usage_test.go
+++ b/usage_test.go
@@ -96,28 +96,39 @@ func (n *MyEnum) MarshalText() ([]byte, error) {
 	return nil, errors.New("There was a problem")
 }
 
-func TestUsageError(t *testing.T) {
-	expectedHelp := `Usage: example [--name NAME]
+func TestUsageWithDefaults(t *testing.T) {
+	expectedHelp := `Usage: example [--label LABEL] [--content CONTENT]
 
 Options:
-  --name NAME [default: error: There was a problem]
+  --label LABEL [default: cat]
+  --content CONTENT [default: dog]
   --help, -h             display this help and exit
 `
 	var args struct {
-		Name *MyEnum
+		Label   string
+		Content string `default:"dog"`
 	}
-	v := MyEnum(42)
-	args.Name = &v
+	args.Label = "cat"
 	p, err := NewParser(Config{"example"}, &args)
-
-	// NB: some might might expect there to be an error here
 	require.NoError(t, err)
 
+	args.Label = "should_ignore_this"
+
 	var help bytes.Buffer
 	p.WriteHelp(&help)
 	assert.Equal(t, expectedHelp, help.String())
 }
 
+func TestUsageCannotMarshalToString(t *testing.T) {
+	var args struct {
+		Name *MyEnum
+	}
+	v := MyEnum(42)
+	args.Name = &v
+	_, err := NewParser(Config{"example"}, &args)
+	assert.EqualError(t, err, `args.Name: error marshaling default value to string: There was a problem`)
+}
+
 func TestUsageLongPositionalWithHelp_legacyForm(t *testing.T) {
 	expectedHelp := `Usage: example VERYLONGPOSITIONALWITHHELP