From aab5b246690f7aa17bb7d6516d896206713d22e6 Mon Sep 17 00:00:00 2001
From: tomonari-t <tomo1208.japan@gmail.com>
Date: Wed, 10 Jun 2020 22:28:00 +0900
Subject: [PATCH] fix(rpc): handle rpc request with empty params

---
 lib/rpc/validation.js  |  2 +-
 test/rpc/validation.js | 52 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 test/rpc/validation.js

diff --git a/lib/rpc/validation.js b/lib/rpc/validation.js
index 5075a61..386ffc7 100644
--- a/lib/rpc/validation.js
+++ b/lib/rpc/validation.js
@@ -8,7 +8,7 @@ module.exports = {
    * @param {Function[]} validators      array of validator
    */
   middleware (method, requiredParamsCount, validators) {
-    return function (params, cb) {
+    return function (params = [], cb) {
       if (params.length < requiredParamsCount) {
         const err = {
           code: INVALID_PARAMS,
diff --git a/test/rpc/validation.js b/test/rpc/validation.js
new file mode 100644
index 0000000..bfed8ec
--- /dev/null
+++ b/test/rpc/validation.js
@@ -0,0 +1,52 @@
+
+const test = require('tape')
+
+const { startRPC } = require('./helpers')
+const { middleware } = require('../../lib/rpc/validation')
+const { baseRequest } = require('./helpers')
+const { checkError } = require('./util')
+const { INVALID_PARAMS } = require('../../lib/rpc/error-code')
+
+const prefix = 'rpc/validation:'
+
+test(`${prefix} should work without \`params\` when it's optional`, t => {
+  const mockMethodName = 'mock'
+  const server = startRPC({
+    [mockMethodName]: middleware((params, cb) => {
+      cb()
+    }, 0, [])
+  })
+
+  const req = {
+    jsonrpc: '2.0',
+    method: mockMethodName,
+    id: 1
+  }
+  const expectRes = res => {
+    t.equal(res.body.error, undefined, 'should not return an error object')
+  }
+  baseRequest(t, server, req, 200, expectRes)
+})
+
+test(`${prefix} should return error without \`params\` when it's required`, t => {
+  const mockMethodName = 'mock'
+  const server = startRPC({
+    [mockMethodName]: middleware((params, cb) => {
+      cb()
+    }, 1, [])
+  })
+
+  const req = {
+    jsonrpc: '2.0',
+    method: mockMethodName,
+    id: 1
+  }
+
+  const expectRes = checkError(
+    t,
+    INVALID_PARAMS,
+    'missing value for required argument 0'
+  )
+
+  baseRequest(t, server, req, 200, expectRes)
+})