perf: 当使用prompt但内容为空时，直接返回prompt的内容 (#138)

pkg/process/prompt.go

@@ -1,16 +1,23 @@
 package process
 
 import (
+	"errors"
+	"fmt"
 	"strings"
 
 	"github.com/eryajf/chatgpt-dingtalk/public"
 )
 
 // GeneratePrompt 生成当次请求的 Prompt
-func GeneratePrompt(msg string) (rst string) {
+func GeneratePrompt(msg string) (rst string, err error) {
 	for _, prompt := range *public.Prompt {
 		if strings.HasPrefix(msg, prompt.Title) {
-			rst = prompt.Content + strings.Replace(msg, prompt.Title, "", -1)
+			if strings.TrimSpace(msg) == prompt.Title {
+				rst = fmt.Sprintf("%s：\n%s", prompt.Title, prompt.Content)
+				err = errors.New("消息内容为空") // 当提示词之后没有文本，抛出异常，以便直接返回Prompt所代表的内容
+			} else {
+				rst = prompt.Content + strings.Replace(msg, prompt.Title, "", -1)
+			}
 			return
 		} else {
 			rst = msg