add key processor

processor/env/processor.go

@@ -6,12 +6,13 @@ import (
 	"os"
 
 	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/param"
 	"gitoa.ru/go-4devs/config/value"
 )
 
 var _ config.ProcessFunc = Env
 
-func Env(_ context.Context, in config.Value) (config.Value, error) {
+func Env(_ context.Context, in config.Value, _ ...param.Option) (config.Value, error) {
 	key, err := in.ParseString()
 	if err != nil {
 		return in, fmt.Errorf("process[env]:%w", err)

processor/key/processor.go

@@ -0,0 +1,49 @@
+package key
+
+import (
+	"context"
+	"fmt"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/param"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+type pkey int
+
+const paramKey pkey = iota
+
+func WithKey(in string) param.Option {
+	return func(p param.Params) param.Params {
+		return param.With(p, paramKey, in)
+	}
+}
+
+func Key(_ context.Context, in config.Value, opts ...param.Option) (config.Value, error) {
+	data := make(map[string]any, 0)
+	if err := in.Unmarshal(&data); err != nil {
+		return nil, fmt.Errorf("unmarshal:%w", err)
+	}
+
+	key, ok := getKey(opts...)
+	if !ok {
+		return nil, fmt.Errorf("key is %w", config.ErrRequired)
+	}
+
+	val, vok := data[key]
+	if !vok {
+		return nil, fmt.Errorf("value by key[%v]: %w", key, config.ErrNotFound)
+	}
+
+	return value.New(val), nil
+}
+
+func getKey(opts ...param.Option) (string, bool) {
+	params := param.New(opts...)
+
+	if name, ok := param.String(params, paramKey); ok {
+		return name, ok
+	}
+
+	return "", false
+}

processor/key/processor_test.go

@@ -0,0 +1,58 @@
+package key_test
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/processor/key"
+	"gitoa.ru/go-4devs/config/test/require"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+func TestKey(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+
+	res, rerr := key.Key(ctx, keyData(t), key.WithKey("key"))
+	require.NoError(t, rerr)
+
+	require.Equal(t, "value", res.String())
+}
+
+func TestKey_required(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+
+	res, rerr := key.Key(ctx, keyData(t))
+	require.ErrorIs(t, rerr, config.ErrRequired)
+
+	require.Equal(t, res, nil)
+}
+
+func TestKey_notFound(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+
+	res, rerr := key.Key(ctx, keyData(t), key.WithKey("wrong"))
+	require.ErrorIs(t, rerr, config.ErrNotFound)
+
+	require.Equal(t, res, nil)
+}
+
+func keyData(t *testing.T) config.Value {
+	t.Helper()
+
+	data := map[string]string{
+		"key": "value",
+	}
+
+	jdata, err := json.Marshal(data)
+	require.NoError(t, err)
+
+	return value.JBytes(jdata)
+}