feat: accept camelcase for config keys (#2651)

* feat: accept camelcase for config keys

* chore: refactor

* chore: refactor

* chore: add more tests

* chore: refactor

* fix: map elements of array

core/conf/config.go

@@ -7,9 +7,13 @@ import (
 	"path"
 	"strings"
 
+	"github.com/zeromicro/go-zero/core/jsonx"
 	"github.com/zeromicro/go-zero/core/mapping"
+	"github.com/zeromicro/go-zero/internal/encoding"
 )
 
+const distanceBetweenUpperAndLower = 32
+
 var loaders = map[string]func([]byte, interface{}) error{
 	".json": LoadFromJsonBytes,
 	".toml": LoadFromTomlBytes,
@@ -49,7 +53,12 @@ func LoadConfig(file string, v interface{}, opts ...Option) error {
 
 // LoadFromJsonBytes loads config into v from content json bytes.
 func LoadFromJsonBytes(content []byte, v interface{}) error {
-	return mapping.UnmarshalJsonBytes(content, v)
+	var m map[string]interface{}
+	if err := jsonx.Unmarshal(content, &m); err != nil {
+		return err
+	}
+
+	return mapping.UnmarshalJsonMap(toCamelCaseKeyMap(m), v, mapping.WithCanonicalKeyFunc(toCamelCase))
 }
 
 // LoadConfigFromJsonBytes loads config into v from content json bytes.
@@ -60,12 +69,22 @@ func LoadConfigFromJsonBytes(content []byte, v interface{}) error {
 
 // LoadFromTomlBytes loads config into v from content toml bytes.
 func LoadFromTomlBytes(content []byte, v interface{}) error {
-	return mapping.UnmarshalTomlBytes(content, v)
+	b, err := encoding.TomlToJson(content)
+	if err != nil {
+		return err
+	}
+
+	return LoadFromJsonBytes(b, v)
 }
 
 // LoadFromYamlBytes loads config into v from content yaml bytes.
 func LoadFromYamlBytes(content []byte, v interface{}) error {
-	return mapping.UnmarshalYamlBytes(content, v)
+	b, err := encoding.YamlToJson(content)
+	if err != nil {
+		return err
+	}
+
+	return LoadFromJsonBytes(b, v)
 }
 
 // LoadConfigFromYamlBytes loads config into v from content yaml bytes.
@@ -80,3 +99,66 @@ func MustLoad(path string, v interface{}, opts ...Option) {
 		log.Fatalf("error: config file %s, %s", path, err.Error())
 	}
 }
+
+func toCamelCase(s string) string {
+	var buf strings.Builder
+	buf.Grow(len(s))
+	var capNext bool
+	boundary := true
+	for _, v := range s {
+		isCap := v >= 'A' && v <= 'Z'
+		isLow := v >= 'a' && v <= 'z'
+		if boundary && (isCap || isLow) {
+			if capNext {
+				if isLow {
+					v -= distanceBetweenUpperAndLower
+				}
+			} else {
+				if isCap {
+					v += distanceBetweenUpperAndLower
+				}
+			}
+			boundary = false
+		}
+		if isCap || isLow {
+			buf.WriteRune(v)
+			capNext = false
+		} else if v == ' ' || v == '\t' {
+			buf.WriteRune(v)
+			capNext = false
+			boundary = true
+		} else if v == '_' {
+			capNext = true
+			boundary = true
+		} else {
+			buf.WriteRune(v)
+			capNext = true
+		}
+	}
+
+	return buf.String()
+}
+
+func toCamelCaseInterface(v interface{}) interface{} {
+	switch vv := v.(type) {
+	case map[string]interface{}:
+		return toCamelCaseKeyMap(vv)
+	case []interface{}:
+		var arr []interface{}
+		for _, vvv := range vv {
+			arr = append(arr, toCamelCaseInterface(vvv))
+		}
+		return arr
+	default:
+		return v
+	}
+}
+
+func toCamelCaseKeyMap(m map[string]interface{}) map[string]interface{} {
+	res := make(map[string]interface{})
+	for k, v := range m {
+		res[toCamelCase(k)] = toCamelCaseInterface(v)
+	}
+
+	return res
+}