diff --git a/assets/js/theme.js b/assets/js/theme.js
index 7512c2ed..5c3739c7 100644
--- a/assets/js/theme.js
+++ b/assets/js/theme.js
@@ -1,3 +1,4 @@
+// TODO use ESLint to check the code style
 import Util from './util';
 
 class FixIt {
@@ -686,12 +687,20 @@ class FixIt {
         if ($echarts.nextElementSibling.tagName === 'TEMPLATE') {
           const chart = echarts.init($echarts, this.isDark ? 'dark' : 'light', { renderer: 'svg' });
           stagingDOM.stage($echarts.nextElementSibling.content.cloneNode(true));
-          // support both JSON and JS object literal
+          let option;
           if ($echarts.nextElementSibling.dataset.fmt === 'js') {
-            eval(`chart.setOption(${stagingDOM.contentAsText()})`);
+            // support JS object literal or JS code
+            const jsCodes = stagingDOM.contentAsText();
+            option = new Function(
+              this.util.isObjectString(jsCodes)
+                ? `return ${jsCodes}`
+                : `${jsCodes} return option`
+            )();
           } else {
-            chart.setOption(stagingDOM.contentAsJson());
+            // support JSON
+            option = stagingDOM.contentAsJson();
           }
+          chart.setOption(option);
           this._echartsArr.push(chart);
         }
       });
diff --git a/assets/js/util.js b/assets/js/util.js
index 6fabd153..af8bad43 100644
--- a/assets/js/util.js
+++ b/assets/js/util.js
@@ -42,7 +42,7 @@ export default class Util {
   isValidDate(date) {
     return date instanceof Date && !isNaN(date.getTime());
   }
-  
+
   /**
    * scroll some element into view
    * @param {String} selector element to scroll
@@ -109,6 +109,23 @@ export default class Util {
         reject();
       }
     });
-    return this.copyText(text); 
+    return this.copyText(text);
+  }
+
+  /**
+   * check if a string is a JS object string
+   * @example isObjectString("{a:1,b:2}") // true
+   * @param {String} str 
+   * @returns 
+   */
+  isObjectString(str) {
+    if (typeof str !== 'string') {
+      return false;
+    }
+    str = str.replace(/\s+/g, ' ').trim();
+    if (str.startsWith('{') && str.endsWith('}')) {
+      return true;
+    }
+    return false;
   }
 }
diff --git a/layouts/partials/init/index.html b/layouts/partials/init/index.html
index c66bd8e8..79384638 100644
--- a/layouts/partials/init/index.html
+++ b/layouts/partials/init/index.html
@@ -1,4 +1,4 @@
-{{- .Scratch.Set "version" "v0.3.20-662a7d57" -}}
+{{- .Scratch.Set "version" "v0.3.20-d41e53bb" -}}
 {{- .Scratch.Set "this" dict -}}
 
 {{- partial "init/detection-env.html" . -}}
diff --git a/layouts/partials/plugin/echarts.html b/layouts/partials/plugin/echarts.html
index f220732b..3be9e778 100644
--- a/layouts/partials/plugin/echarts.html
+++ b/layouts/partials/plugin/echarts.html
@@ -9,9 +9,6 @@
   {{- if hugo.IsProduction -}}
     {{- $content = replaceRE `[\s]+` " " $content -}}
   {{- end -}}
-  {{- if not ((hasPrefix $content "{") | and (hasSuffix $content "}")) -}}
-    {{- errorf "ECharts format error\nPlease use JS object literal for Echarts, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Grammar_and_types#object_literals" -}}
-  {{- end -}}
   <template data-fmt="js">{{ $content | safeJS }}</template>
 {{- else -}}
   <template>{{ .Inner | transform.Unmarshal | jsonify }}</template>