feat: add biz handler

app.js

@@ -12,6 +12,8 @@ const {
 } = require('./lib/utils');
 
 module.exports = app => {
+  app.config.coreMiddleware.push('onerrorBizHandler');
+
   // logging error
   const config = app.config.onerror;
   const viewTemplate = fs.readFileSync(config.templatePath, 'utf8');

app/middleware/onerror_biz_handler.js

@@ -0,0 +1,57 @@
+'use strict';
+
+const { EggError, ErrorType } = require('egg-errors');
+const { accepts } = require('./lib/utils');
+
+module.exports = (_, app) => {
+  const biz = app.config.onerror.biz;
+
+  return async function onerrorBizHandler(ctx, next) {
+    try {
+      await next();
+    } catch (err) {
+      const fn = app.config.onerror.accepts || accepts;
+      const contentType = fn(ctx);
+
+      const type = EggError.getType(err);
+      switch (type) {
+        case ErrorType.ERROR: {
+          ctx.status = err.status || 500;
+          ctx.body = format(err, contentType);
+          break;
+        }
+
+        case ErrorType.EXCEPTION: {
+          ctx.logger.error(err);
+          err.status = 500;
+          ctx.body = format(err, contentType);
+          break;
+        }
+
+        case ErrorType.BUILTIN:
+        default:
+          throw err;
+      }
+    }
+
+    function format(err, contentType) {
+      if (contentType === 'json' && biz.formatJSON) {
+        ctx.body = biz.formatJSON(err);
+      if (contentType === 'text' && biz.formatText) {
+        ctx.body = biz.formatText(err);
+      if (contentType === 'html' && biz.formatHtml) {
+        ctx.body = biz.formatHtml(err);
+      } else {
+        ctx.body = defaultFormat(err);
+      }
+    }
+  };
+
+};
+
+function defaultFormat(err) {
+  return {
+    code: err.code,
+    message: err.message,
+  };
+}

config/config.default.js

@@ -11,4 +11,15 @@ exports.onerror = {
   appErrorFilter: null,
   // default template path
   templatePath: path.join(__dirname, '../lib/onerror_page.mustache'),
+  // normalize your error response from error object
+  biz: {
+    formatJSON: null,
+    formatText: null,
+    formatHtml: null,
+  },
+  system: {
+    formatJSON: null,
+    formatText: null,
+    formatHtml: null,
+  },
 };