diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..0063a3d
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,12 @@
+name: github-actions
+on: [push]
+jobs:
+  check-bats-version:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: '14'
+      - run: npm install -g bats
+      - run: bats -v
diff --git a/lib/add.js b/lib/add.js
index 1714b95..83eff59 100644
--- a/lib/add.js
+++ b/lib/add.js
@@ -1,5 +1,41 @@
-function add() {
+function add(a, b) {
   // 实现该函数
+  // 非数字报错
+  if(isNaN(a) || isNaN(b)) throw Error('需要传入数字或字符串型数字')
+  const maxLength = 16
+  // 边界：16位以内可以正常相加
+  if(String(a).length<maxLength && String(b).length<maxLength) {
+    return String(Number(a) + Number(b))
+  }
+
+  // 以10位数作一个阈值进行分割
+  const aList = a.match(/\d{1,10}/g)
+  const bList = b.match(/\d{1,10}/g)
+  
+  // 两数的最大长度作为结果数组的长度，+1一个长度防止满十进一
+  let resultLength = Math.max(aList.length, bList.length)
+  let addResultList = Array(resultLength+1).fill('')
+  let aLength = aList.length - 1
+  let bLength = bList.length - 1
+  // 从尾部开始计算，两两相加后把结果加到结果数组上
+  // 如果两数相加长度大于a/b的最大长度，说明是首位满十，往结果数组的前一位进一
+  while(aLength>=0 || bLength>=0) {
+    const resultTemp = Number(aList[aLength] || 0) + Number(bList[bLength] || 0)
+    // 判断长度是否溢出
+    if(resultTemp.length > Math.max(aList[aLength].length, bList[bLength].length)) {
+      addResultList[resultLength - 1] = 1
+      resultTemp = resultTemp.slice(1)
+    }
+    addResultList[resultLength] = addResultList[resultLength] + resultTemp
+
+    aLength--
+    bLength--
+    resultLength--
+  }
+
+  const result = addResultList.join('')
+
+  return result
 }
 
 module.exports = add
\ No newline at end of file
diff --git a/test/test.spec.js b/test/test.spec.js
index 935b70e..6ec6493 100644
--- a/test/test.spec.js
+++ b/test/test.spec.js
@@ -8,4 +8,6 @@ describe('大数相加add方法', function () {
   test('"843529812342341234"加上"236124361425345435"等于"1079654173767686669"', function () {
     expect(add('843529812342341234', '236124361425345435')).toBe('1079654173767686669')
   })
-})
\ No newline at end of file
+})
+
+// test: add git actions
\ No newline at end of file