fix:修正部分极端情况导致的解析表情报错问题；更改测试端口

lib/helper.js

     }
     // 如果不存在对应的表情, 则返回原文
     // const emoji = emojiObejct[src];
-    var emoji = JSON.parse(sessionStorage.getItem("emojiMap"))[src];
-    if (emoji) {
-      return "<img class=\"comment-emoji\" src=\"" + emoji + "\" alt=\"" + emoji.title + "\" style=\"width:28px\"/>";
+    if(sessionStorage.getItem("emojiMap") && JSON.parse(sessionStorage.getItem("emojiMap"))){
+      var emoji = JSON.parse(sessionStorage.getItem("emojiMap"))[src];
+      if (emoji) {
+        return "<img class=\"comment-emoji\" src=\"" + emoji + "\" alt=\"" + emoji.title + "\" style=\"width:28px\"/>";
+      }
     }
     return "[" + src + "]";
   }).replace(innerUrl, function (a, b) {

package.json

   "scripts": {
     "precommit": "lint-staged",
     "prettier": "prettier --single-quote --trailing-comma=es5 --write 'src/**/*.{js,jsx,json,css,less}'",
-    "start": "react-app-rewired start",
+    "start": "cross-env PORT=3001 react-app-rewired start",
     "build": "react-app-rewired build",
     "test": "react-app-rewired test --env=jsdom",
     "eject": "react-scripts eject",
     "lib": "babel ./src --out-dir ./lib --source-maps --copy-files"
   },
   "devDependencies": {
+    "cross-env": "^5.2.0",
     "babel-cli": "^6.26.0",
     "babel-plugin-import": "^1.8.0",
     "babel-plugin-transform-object-rest-spread": "^6.26.0",

src/helper.js

       }
       // 如果不存在对应的表情, 则返回原文
       // const emoji = emojiObejct[src];
-      const emoji = JSON.parse(sessionStorage.getItem("emojiMap"))[src];
-      if (emoji) {
-        return `<img class="comment-emoji" src="${emoji}" alt="${emoji.title}" style="width:28px"/>`;
+      if (
+        sessionStorage.getItem("emojiMap") &&
+        JSON.parse(sessionStorage.getItem("emojiMap"))
+      ) {
+        const emoji = JSON.parse(sessionStorage.getItem("emojiMap"))[src];
+        if (emoji) {
+          return `<img class="comment-emoji" src="${emoji}" alt="${
+            emoji.title
+          }" style="width:28px"/>`;
+        }
       }
       return `[${src}]`;
     })