feat: add resident miniapp MVP

miniapp/miniprogram/api/expressApi.test.js

@@ -0,0 +1,9 @@
+const { calculateExpressFeeCent } = require('./expressApi')
+
+describe('calculateExpressFeeCent', () => {
+  test('matches backend express fee rule', () => {
+    expect(calculateExpressFeeCent(1)).toBe(300)
+    expect(calculateExpressFeeCent(2)).toBe(400)
+    expect(calculateExpressFeeCent(4)).toBe(600)
+  })
+})