feature: file namestyle (#223)

* add api filename style

* new feature: config.yaml

* optimize

* optimize logic generation

* check hanlder valid

* optimize

* reactor naming style

* optimize

* optimize test

* optimize gen middleware

* format

Co-authored-by: anqiansong <anqiansong@xiaoheiban.cn>
Co-authored-by: kim <xutao@xiaoheiban.cn>

tools/goctl/config/config.go

@@ -0,0 +1,122 @@
+package config
+
+import (
+	"errors"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/tal-tech/go-zero/tools/goctl/util"
+	"gopkg.in/yaml.v2"
+)
+
+const (
+	configFile    = "config.yaml"
+	configFolder  = "config"
+	DefaultFormat = "gozero"
+)
+
+const defaultYaml = `# namingFormat is used to define the naming format of the generated file name.
+# just like time formatting, you can specify the formatting style through the
+# two format characters go, and zero. for example: snake format you can
+# define as go_zero, camel case format you can it is defined as goZero,
+# and even split characters can be specified, such as go#zero. in theory,
+# any combination can be used, but the prerequisite must meet the naming conventions
+# of each operating system file name. if you want to independently control the file 
+# naming style of the api, rpc, and model layers, you can set it through apiNamingFormat, 
+# rpcNamingFormat, modelNamingFormat, and independent control is not enabled by default. 
+# for more information, please see #{apiNamingFormat},#{rpcNamingFormat},#{modelNamingFormat}
+# Note: namingFormat is based on snake or camel string
+namingFormat: gozero
+`
+
+type Config struct {
+	// NamingFormat is used to define the naming format of the generated file name.
+	// just like time formatting, you can specify the formatting style through the
+	// two format characters go, and zero. for example: snake format you can
+	// define as go_zero, camel case format you can it is defined as goZero,
+	// and even split characters can be specified, such as go#zero. in theory,
+	// any combination can be used, but the prerequisite must meet the naming conventions
+	// of each operating system file name.
+	// Note: NamingFormat is based on snake or camel string
+	NamingFormat string `yaml:"namingFormat"`
+}
+
+func NewConfig(format string) (*Config, error) {
+	if len(format) == 0 {
+		format = DefaultFormat
+	}
+	cfg := &Config{NamingFormat: format}
+	err := validate(cfg)
+	return cfg, err
+}
+
+func InitOrGetConfig() (*Config, error) {
+	var (
+		defaultConfig Config
+	)
+	err := yaml.Unmarshal([]byte(defaultYaml), &defaultConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	goctlHome, err := util.GetGoctlHome()
+	if err != nil {
+		return nil, err
+	}
+
+	configDir := filepath.Join(goctlHome, configFolder)
+	configFilename := filepath.Join(configDir, configFile)
+	if util.FileExists(configFilename) {
+		data, err := ioutil.ReadFile(configFilename)
+		if err != nil {
+			return nil, err
+		}
+
+		err = yaml.Unmarshal(data, &defaultConfig)
+		if err != nil {
+			return nil, err
+		}
+
+		err = validate(&defaultConfig)
+		if err != nil {
+			return nil, err
+		}
+
+		return &defaultConfig, nil
+	}
+
+	err = util.MkdirIfNotExist(configDir)
+	if err != nil {
+		return nil, err
+	}
+
+	f, err := os.Create(configFilename)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		_ = f.Close()
+	}()
+
+	_, err = f.WriteString(defaultYaml)
+	if err != nil {
+		return nil, err
+	}
+
+	err = validate(&defaultConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return &defaultConfig, nil
+}
+
+func validate(cfg *Config) error {
+	if len(strings.TrimSpace(cfg.NamingFormat)) == 0 {
+		return errors.New("missing namingFormat")
+	}
+	return nil
+}

tools/goctl/config/readme.md

@@ -0,0 +1,50 @@
+# 配置项管理
+
+| 名称              | 是否可选 | 说明                                          |
+|-------------------|----------|-----------------------------------------------|
+| namingFormat      | YES      | 文件名称格式化符                      |
+
+# naming-format
+`namingFormat`可以用于对生成代码的文件名称进行格式化，和日期格式化符（yyyy-MM-dd）类似，在代码生成时可以根据这些配置项的格式化符进行格式化。
+
+## 格式化符(gozero)
+格式化符有`go`,`zero`组成，如常见的三种格式化风格你可以这样编写：
+* lower: `gozero`
+* camel: `goZero`
+* snake: `go_zero`
+
+常见格式化符生成示例
+源字符：welcome_to_go_zero
+
+| 格式化符   | 格式化结果            | 说明                      |
+|------------|-----------------------|---------------------------|
+| gozero     | welcometogozero       | 小写                      |
+| goZero     | welcomeToGoZero       | 驼峰                      |
+| go_zero    | welcome_to_go_zero    | snake                     |
+| Go#zero    | Welcome#to#go#zero    | #号分割Title类型          |
+| GOZERO     | WELCOMETOGOZERO       | 大写                      |
+| \_go#zero_ | \_welcome#to#go#zero_ | 下划线做前后缀，并且#分割 |
+
+错误格式化符示例
+* go
+* gOZero
+* zero
+* goZEro
+* goZERo
+* goZeRo
+* tal
+
+# 使用方法
+目前可通过在生成api、rpc、model时通过`--style`参数指定format格式，如：
+```shell script
+goctl api go test.api -dir . -style gozero
+```
+```shell script
+ goctl rpc proto -src test.proto -dir . -style go_zero
+```
+```shell script
+goctl model mysql datasource -url="" -table="*" -dir ./snake -style GoZero
+```
+
+# 默认值
+当不指定-style时默认值为`gozero`