viper/internal/encoding/yaml/codec_test.go

package yaml

import (
	"reflect"
	"testing"
)

// original form of the data
const original = `# key-value pair
key: value
list:
    - item1
    - item2
    - item3
map:
    key: value

# nested
# map
nested_map:
    map:
        key: value
        list:
            - item1
            - item2
            - item3
`

// encoded form of the data
const encoded = `key: value
list:
    - item1
    - item2
    - item3
map:
    key: value
nested_map:
    map:
        key: value
        list:
            - item1
            - item2
            - item3
`

// decoded form of the data
//
// in case of YAML it's slightly different from Viper's internal representation
// (eg. map is decoded into a map with interface key)
var decoded = map[string]any{
	"key": "value",
	"list": []any{
		"item1",
		"item2",
		"item3",
	},
	"map": map[string]any{
		"key": "value",
	},
	"nested_map": map[string]any{
		"map": map[string]any{
			"key": "value",
			"list": []any{
				"item1",
				"item2",
				"item3",
			},
		},
	},
}

// Viper's internal representation
var data = map[string]any{
	"key": "value",
	"list": []any{
		"item1",
		"item2",
		"item3",
	},
	"map": map[string]any{
		"key": "value",
	},
	"nested_map": map[string]any{
		"map": map[string]any{
			"key": "value",
			"list": []any{
				"item1",
				"item2",
				"item3",
			},
		},
	},
}

func TestCodec_Encode(t *testing.T) {
	codec := Codec{}

	b, err := codec.Encode(data)
	if err != nil {
		t.Fatal(err)
	}

	if encoded != string(b) {
		t.Fatalf("decoded value does not match the expected one\nactual:   %#v\nexpected: %#v", string(b), encoded)
	}
}

func TestCodec_Decode(t *testing.T) {
	t.Run("OK", func(t *testing.T) {
		codec := Codec{}

		v := map[string]any{}

		err := codec.Decode([]byte(original), v)
		if err != nil {
			t.Fatal(err)
		}

		if !reflect.DeepEqual(decoded, v) {
			t.Fatalf("decoded value does not match the expected one\nactual:   %#v\nexpected: %#v", v, decoded)
		}
	})

	t.Run("InvalidData", func(t *testing.T) {
		codec := Codec{}

		v := map[string]any{}

		err := codec.Decode([]byte(`invalid data`), v)
		if err == nil {
			t.Fatal("expected decoding to fail")
		}

		t.Logf("decoding failed as expected: %s", err)
	})
}