diff --git a/.github/workflows/learn-github-actions.yml b/.github/workflows/learn-github-actions.yml
new file mode 100644
index 0000000..017593f
--- /dev/null
+++ b/.github/workflows/learn-github-actions.yml
@@ -0,0 +1,12 @@
+name: learn-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
\ No newline at end of file
diff --git a/.github/workflows/run-test.yml b/.github/workflows/run-test.yml
new file mode 100644
index 0000000..30ec535
--- /dev/null
+++ b/.github/workflows/run-test.yml
@@ -0,0 +1,30 @@
+# This workflow will do a clean installation of node dependencies, cache/restore them, build the source code and run tests across different versions of node
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
+
+name: run-test
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [14.x, 16.x]
+        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v3
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'yarn'
+    - run: yarn
+    - run: yarn test
diff --git a/lib/add.js b/lib/add.js
index 1714b95..3b9c2b7 100644
--- a/lib/add.js
+++ b/lib/add.js
@@ -1,5 +1,20 @@
-function add() {
+function add(a, b) {
   // 实现该函数
+  const maxLength = Math.max(a.length, b.length);
+  const aPad = a.padStart(maxLength, "0");
+  const bPad = b.padStart(maxLength, "0");
+
+  let sum = "";
+  let f = 0;
+  for (let i = maxLength - 1; i >= 0; i--) {
+    const digit = parseInt(aPad[i]) + parseInt(bPad[i]) + f;
+    f = Math.floor(digit / 10);
+    sum = (digit % 10) + sum;
+  }
+  if (f === 1) {
+    sum = "1" + sum;
+  }
+  return sum;
 }
 
-module.exports = add
\ No newline at end of file
+module.exports = add;