diff --git a/.editorconfig b/.editorconfig
index 0d46254..b40d053 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -25,6 +25,13 @@ spaces_around_brackets = none
 indent_brace_style = allman
 
 
+# JavaScript/TypeScript
+[*.{js,ts}]
+indent_style = space
+curly_bracket_next_line = false
+indent_brace_style = K&R
+
+
 # JSON/YAML
 [*.{json,babelrc,code-workspace,yml,yaml}]
 indent_style = space
diff --git a/.eslintrc.yml b/.eslintrc.yml
index 7cea633..59697b3 100644
--- a/.eslintrc.yml
+++ b/.eslintrc.yml
@@ -29,9 +29,7 @@ rules: # https://eslint.org/docs/rules/
     before: true
   block-scoped-var: error
   block-spacing: error
-  brace-style:
-  - error
-  - allman
+  brace-style: 'off' # see "@typescript-eslint/brace-style"
   callback-return: error
   capitalized-comments: 'off'
   class-methods-use-this: error
@@ -87,26 +85,14 @@ rules: # https://eslint.org/docs/rules/
   - below
   indent:
   - error
-  - tab
+  - 4
+  - SwitchCase: 1
   indent-legacy: 'off'
   init-declarations: error
   jsx-quotes: error
   key-spacing: error
   keyword-spacing:
   - error
-  - overrides:
-      catch:
-        after: false
-      for:
-        after: false
-      if:
-        after: false
-      switch:
-        after: false
-      while:
-        after: false
-      with:
-        after: false
   line-comment-position: 'off'
   linebreak-style:
   - error
@@ -256,7 +242,7 @@ rules: # https://eslint.org/docs/rules/
   rest-spread-spacing:
   - error
   - never
-  semi: error
+  semi: 'off' # see "@typescript-eslint/semi"
   semi-spacing: error
   semi-style:
   - error
@@ -308,8 +294,21 @@ rules: # https://eslint.org/docs/rules/
 
   # @typescript-eslint plugin
   "@typescript-eslint/ban-ts-ignore": 'off'
+  "@typescript-eslint/brace-style":
+  - error
+  - 1tbs
+  "@typescript-eslint/member-delimiter-style":
+  - error
+  - multiline:
+      delimiter: semi
+      requireLast: true
+    singleline:
+      delimiter: semi
+      requireLast: true
   "@typescript-eslint/no-empty-interface": 'off'
+  "@typescript-eslint/no-floating-promises": error
   "@typescript-eslint/no-use-before-define":
   - error
   - functions: false
+  "@typescript-eslint/semi": error
   "@typescript-eslint/strict-boolean-expressions": error
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c8ddc4f..2561371 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,10 +13,13 @@ jobs:
       matrix:
         os:
         - Windows-2019
+        - Windows-2022
         - macOS-10.15
-        - Ubuntu-16.04
+        - macOS-11
+        - macOS-12
         - Ubuntu-18.04
         - Ubuntu-20.04
+        - Ubuntu-22.04
         nodejs:
         - 12
       fail-fast: false
diff --git a/.github/workflows/verify-on-container-alpine.yml b/.github/workflows/verify-on-container-alpine.yml
index 762518b..e716f3b 100644
--- a/.github/workflows/verify-on-container-alpine.yml
+++ b/.github/workflows/verify-on-container-alpine.yml
@@ -15,6 +15,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -44,6 +45,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -73,6 +75,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -104,6 +107,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -139,6 +143,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -170,6 +175,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -205,6 +211,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -236,6 +243,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -272,6 +280,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
@@ -303,6 +312,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - alpine:3.10
         - alpine:3.11
diff --git a/.github/workflows/verify-on-container-centos.yml b/.github/workflows/verify-on-container-centos.yml
index dc45b81..8318e4a 100644
--- a/.github/workflows/verify-on-container-centos.yml
+++ b/.github/workflows/verify-on-container-centos.yml
@@ -15,9 +15,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
       fail-fast: false
     steps:
     - name: Install packages
@@ -43,9 +44,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
       fail-fast: false
     steps:
     - name: Install packages
@@ -71,9 +73,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
       fail-fast: false
     steps:
     - name: Install packages
@@ -101,9 +104,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
@@ -135,9 +139,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
@@ -165,9 +170,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
@@ -199,9 +205,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
@@ -229,9 +236,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
@@ -264,9 +272,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
@@ -294,9 +303,10 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
-        - centos:7
-        - centos:8
+        - quay.io/centos/centos:centos7
+        - quay.io/centos/centos:stream8
     steps:
     - name: Install packages
       run: |
diff --git a/.github/workflows/verify-on-container-ubuntu.yml b/.github/workflows/verify-on-container-ubuntu.yml
index ed512e2..1abf004 100644
--- a/.github/workflows/verify-on-container-ubuntu.yml
+++ b/.github/workflows/verify-on-container-ubuntu.yml
@@ -15,10 +15,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
       fail-fast: false
     steps:
     - name: Install packages
@@ -45,10 +47,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
       fail-fast: false
     steps:
     - name: Install packages
@@ -75,10 +79,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
       fail-fast: false
     steps:
     - name: Install packages
@@ -107,10 +113,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
@@ -143,10 +151,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
@@ -175,10 +185,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
@@ -211,10 +223,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
@@ -243,10 +257,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
@@ -280,10 +296,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
@@ -312,10 +330,12 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
         container:
         - ubuntu:16.04
         - ubuntu:18.04
         - ubuntu:20.04
+        - ubuntu:22.04
     steps:
     - name: Install packages
       run: |
diff --git a/.github/workflows/verify-on-macos.yml b/.github/workflows/verify-on-macos.yml
index 251147a..e1b7e82 100644
--- a/.github/workflows/verify-on-macos.yml
+++ b/.github/workflows/verify-on-macos.yml
@@ -14,6 +14,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -34,6 +36,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -54,6 +58,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -74,6 +80,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -101,6 +109,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -127,6 +137,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -149,6 +161,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -175,6 +189,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -197,6 +213,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -224,6 +242,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -246,6 +266,8 @@ jobs:
       matrix:
         os:
         - macos-10.15
+        - macos-11
+        - macos-12
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
diff --git a/.github/workflows/verify-on-ubuntu.yml b/.github/workflows/verify-on-ubuntu.yml
index 67dc3f6..f31c00d 100644
--- a/.github/workflows/verify-on-ubuntu.yml
+++ b/.github/workflows/verify-on-ubuntu.yml
@@ -36,6 +36,7 @@ jobs:
         os:
         - ubuntu-18.04
         - ubuntu-20.04
+        - ubuntu-22.04
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
diff --git a/.github/workflows/verify-on-windows.yml b/.github/workflows/verify-on-windows.yml
index adadd87..5dc222a 100644
--- a/.github/workflows/verify-on-windows.yml
+++ b/.github/workflows/verify-on-windows.yml
@@ -13,8 +13,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -34,8 +34,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -55,8 +55,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -76,8 +76,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -104,8 +104,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -131,8 +131,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -154,8 +154,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -181,8 +181,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -204,8 +204,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -232,8 +232,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
@@ -255,8 +255,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - windows-2016
         - windows-2019
+        - windows-2022
     steps:
     - name: Checkout source codes
       uses: actions/checkout@v2
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0dde2b4..f5eb524 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Others
+
+* add `windows-2022`, `macos-11`, `macos-12`, `ubuntu-22.04`, and `CentOS 8 Stream (Docker container)`
+* drop `ubuntu-16.04`, and `CentOS 8 (Docker container)`
+
 ## [2.3.1] - 2021-08-01
 
 ### Security
diff --git a/README.md b/README.md
index 6e3e615..f249ed9 100644
--- a/README.md
+++ b/README.md
@@ -17,9 +17,9 @@ Useful for SCP, SFTP, and `rsync` over SSH in deployment script.
 
 tested on:
 
-* [all available virtual machines](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/virtual-environments-for-github-hosted-runners#supported-runners-and-hardware-resources) (Windows Server 2019/2016, macOS Catalina, and Ubuntu 20.04/18.04)
+* [all available virtual machines](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/virtual-environments-for-github-hosted-runners#supported-runners-and-hardware-resources) (Windows Server 2022/2019, macOS Monterey/Big Sur/Catalina, and Ubuntu 22.04/20.04/18.04)
 * [Docker container (Ubuntu)](https://hub.docker.com/_/ubuntu) / requires `openssh-client` package; `apt install -y openssh-client`
-* [Docker container (CentOS)](https://hub.docker.com/_/centos) / requires `openssh-clients` package; `yum install -y openssh-clients`
+* [Docker container (CentOS)](https://quay.io/repository/centos/centos) / requires `openssh-clients` package; `yum install -y openssh-clients`
 * [Docker container (Alpine Linux)](https://hub.docker.com/_/alpine) / requires `openssh-client` package; `apk add openssh-client`
 
 ## Usage
diff --git a/lib/index.js b/lib/index.js
index 88bd249..e57705c 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -586,74 +586,85 @@ __nccwpck_require__.r(__webpack_exports__);
 
 
 
+try {
+    main();
+}
+catch (err) {
+    if (err instanceof Error) {
+        _actions_core__WEBPACK_IMPORTED_MODULE_2__.setFailed(err);
+    }
+}
 /**
  * main function
  */
 function main() {
-    try {
-        // parameters
-        const key = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("key", {
-            required: true,
+    // parameters
+    const key = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("key", {
+        required: true,
+    });
+    const name = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("name");
+    const knownHosts = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("known_hosts", {
+        required: true,
+    });
+    const config = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("config");
+    const ifKeyExists = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("if_key_exists");
+    // create ".ssh" directory
+    const sshDirName = createSshDirectory();
+    // files to be created
+    const files = [];
+    if (shouldCreateKeyFile(path__WEBPACK_IMPORTED_MODULE_1___default().join(sshDirName, name), ifKeyExists)) {
+        files.push({
+            name: name,
+            contents: insertLf(key, false, true),
+            options: {
+                mode: 0o400,
+                flag: "wx",
+            },
         });
-        const name = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("name");
-        const knownHosts = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("known_hosts", {
-            required: true,
-        });
-        const config = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("config");
-        const ifKeyExists = _actions_core__WEBPACK_IMPORTED_MODULE_2__.getInput("if_key_exists");
-        // create ".ssh" directory
-        const home = getHomeDirectory();
-        const dirName = path__WEBPACK_IMPORTED_MODULE_1___default().resolve(home, ".ssh");
-        fs__WEBPACK_IMPORTED_MODULE_0___default().mkdirSync(dirName, {
-            recursive: true,
-            mode: 0o700,
-        });
-        // files to be created
-        const files = [];
-        if (shouldCreateKeyFile(path__WEBPACK_IMPORTED_MODULE_1___default().join(dirName, name), ifKeyExists)) {
-            files.push({
-                name: name,
-                contents: insertLf(key, false, true),
-                options: {
-                    mode: 0o400,
-                    flag: "wx",
-                },
-            });
-        }
-        if (knownHosts !== "unnecessary") {
-            files.push({
-                name: "known_hosts",
-                contents: insertLf(knownHosts, true, true),
-                options: {
-                    mode: 0o644,
-                    flag: "a",
-                },
-            });
-        }
-        if (config !== "") {
-            files.push({
-                name: "config",
-                contents: insertLf(config, true, true),
-                options: {
-                    mode: 0o644,
-                    flag: "a",
-                },
-            });
-        }
-        // create files
-        for (const file of files) {
-            const fileName = path__WEBPACK_IMPORTED_MODULE_1___default().join(dirName, file.name);
-            fs__WEBPACK_IMPORTED_MODULE_0___default().writeFileSync(fileName, file.contents, file.options);
-        }
-        console.log(`SSH key has been stored to ${dirName} successfully.`);
     }
-    catch (err) {
-        _actions_core__WEBPACK_IMPORTED_MODULE_2__.setFailed(err.message);
+    if (knownHosts !== "unnecessary") {
+        files.push({
+            name: "known_hosts",
+            contents: insertLf(knownHosts, true, true),
+            options: {
+                mode: 0o644,
+                flag: "a",
+            },
+        });
     }
+    if (config !== "") {
+        files.push({
+            name: "config",
+            contents: insertLf(config, true, true),
+            options: {
+                mode: 0o644,
+                flag: "a",
+            },
+        });
+    }
+    // create files
+    for (const file of files) {
+        const fileName = path__WEBPACK_IMPORTED_MODULE_1___default().join(sshDirName, file.name);
+        fs__WEBPACK_IMPORTED_MODULE_0___default().writeFileSync(fileName, file.contents, file.options);
+    }
+    console.log(`SSH key has been stored to ${sshDirName} successfully.`);
+}
+/**
+ * create ".ssh" directory
+ * @returns directory name
+ */
+function createSshDirectory() {
+    const home = getHomeDirectory();
+    const dirName = path__WEBPACK_IMPORTED_MODULE_1___default().resolve(home, ".ssh");
+    fs__WEBPACK_IMPORTED_MODULE_0___default().mkdirSync(dirName, {
+        recursive: true,
+        mode: 0o700,
+    });
+    return dirName;
 }
 /**
  * get home directory
- * @returns home directory
+ * @returns home directory name
  */
 function getHomeDirectory() {
     const homeEnv = getHomeEnv();
@@ -724,7 +735,6 @@ function shouldCreateKeyFile(keyFilePath, ifKeyExists) {
             throw new Error(`SSH key is already installed. Set "if_key_exists" to "replace" or "ignore" in order to avoid this error.`);
     }
 }
-main();
 
 })();
 
diff --git a/src/main.ts b/src/main.ts
index 737ec57..1dbc3df 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -3,126 +3,125 @@ import path from "path";
 
 import * as core from "@actions/core";
 
-interface FileInfo
-{
-	name: string;
-	contents: string;
-	options: fs.WriteFileOptions;
+interface FileInfo {
+    name: string;
+    contents: string;
+    options: fs.WriteFileOptions;
+}
+
+try {
+    main();
+} catch (err) {
+    if (err instanceof Error) {
+        core.setFailed(err);
+    }
 }
 
 /**
  * main function
  */
-function main(): void
-{
-	try
-	{
-		// parameters
-		const key = core.getInput("key", {
-			required: true,
-		});
-		const name = core.getInput("name");
-		const knownHosts = core.getInput("known_hosts", {
-			required: true,
-		});
-		const config = core.getInput("config");
-		const ifKeyExists = core.getInput("if_key_exists");
+function main(): void {
+    // parameters
+    const key = core.getInput("key", {
+        required: true,
+    });
+    const name = core.getInput("name");
+    const knownHosts = core.getInput("known_hosts", {
+        required: true,
+    });
+    const config = core.getInput("config");
+    const ifKeyExists = core.getInput("if_key_exists");
 
-		// create ".ssh" directory
-		const home = getHomeDirectory();
-		const dirName = path.resolve(home, ".ssh");
-		fs.mkdirSync(dirName, {
-			recursive: true,
-			mode: 0o700,
-		});
+    // create ".ssh" directory
+    const sshDirName = createSshDirectory();
 
-		// files to be created
-		const files: FileInfo[] = [];
-		if(shouldCreateKeyFile(path.join(dirName, name), ifKeyExists))
-		{
-			files.push({
-				name: name,
-				contents: insertLf(key, false, true),
-				options: {
-					mode: 0o400,
-					flag: "wx",
-				},
-			});
-		}
-		if(knownHosts !== "unnecessary")
-		{
-			files.push({
-				name: "known_hosts",
-				contents: insertLf(knownHosts, true, true),
-				options: {
-					mode: 0o644,
-					flag: "a",
-				},
-			});
-		}
-		if(config !== "")
-		{
-			files.push({
-				name: "config",
-				contents: insertLf(config, true, true),
-				options: {
-					mode: 0o644,
-					flag: "a",
-				},
-			});
-		}
+    // files to be created
+    const files: FileInfo[] = [];
+    if (shouldCreateKeyFile(path.join(sshDirName, name), ifKeyExists)) {
+        files.push({
+            name: name,
+            contents: insertLf(key, false, true),
+            options: {
+                mode: 0o400,
+                flag: "wx",
+            },
+        });
+    }
+    if (knownHosts !== "unnecessary") {
+        files.push({
+            name: "known_hosts",
+            contents: insertLf(knownHosts, true, true),
+            options: {
+                mode: 0o644,
+                flag: "a",
+            },
+        });
+    }
+    if (config !== "") {
+        files.push({
+            name: "config",
+            contents: insertLf(config, true, true),
+            options: {
+                mode: 0o644,
+                flag: "a",
+            },
+        });
+    }
 
-		// create files
-		for(const file of files)
-		{
-			const fileName = path.join(dirName, file.name);
-			fs.writeFileSync(fileName, file.contents, file.options);
-		}
+    // create files
+    for (const file of files) {
+        const fileName = path.join(sshDirName, file.name);
+        fs.writeFileSync(fileName, file.contents, file.options);
+    }
 
-		console.log(`SSH key has been stored to ${dirName} successfully.`);
-	}
-	catch(err)
-	{
-		core.setFailed(err.message);
-	}
+    console.log(`SSH key has been stored to ${sshDirName} successfully.`);
+}
+
+/**
+ * create ".ssh" directory
+ * @returns directory name
+ */
+function createSshDirectory(): string {
+    const home = getHomeDirectory();
+    const dirName = path.resolve(home, ".ssh");
+    fs.mkdirSync(dirName, {
+        recursive: true,
+        mode: 0o700,
+    });
+    return dirName;
 }
 
 /**
  * get home directory
- * @returns home directory
+ * @returns home directory name
  */
-function getHomeDirectory(): string
-{
-	const homeEnv = getHomeEnv();
-	const home = process.env[homeEnv];
-	if(home === undefined)
-	{
-		throw Error(`${homeEnv} is not defined`);
-	}
+function getHomeDirectory(): string {
+    const homeEnv = getHomeEnv();
+    const home = process.env[homeEnv];
+    if (home === undefined) {
+        throw Error(`${homeEnv} is not defined`);
+    }
 
-	if(home === "/github/home")
-	{
-		// Docker container
-		return "/root";
-	}
+    if (home === "/github/home") {
+        // Docker container
+        return "/root";
+    }
 
-	return home;
+    return home;
 }
 
 /**
  * get HOME environment name
  * @returns HOME environment name
  */
-function getHomeEnv(): string
-{
-	if(process.platform === "win32")
-	{
-		// Windows
-		return "USERPROFILE";
-	}
+function getHomeEnv(): string {
+    if (process.platform === "win32") {
+        // Windows
+        return "USERPROFILE";
+    }
 
-	// macOS / Linux
-	return "HOME";
+    // macOS / Linux
+    return "HOME";
 }
 
 /**
@@ -132,25 +131,21 @@ function getHomeEnv(): string
  * @param append true to append
  * @returns new value
  */
-function insertLf(value: string, prepend: boolean, append: boolean): string
-{
-	let affectedValue = value;
+function insertLf(value: string, prepend: boolean, append: boolean): string {
+    let affectedValue = value;
 
-	if(value.length === 0)
-	{
-		// do nothing if empty
-		return "";
-	}
-	if(prepend && !affectedValue.startsWith("\n"))
-	{
-		affectedValue = `\n${affectedValue}`;
-	}
-	if(append && !affectedValue.endsWith("\n"))
-	{
-		affectedValue = `${affectedValue}\n`;
-	}
+    if (value.length === 0) {
+        // do nothing if empty
+        return "";
+    }
+    if (prepend && !affectedValue.startsWith("\n")) {
+        affectedValue = `\n${affectedValue}`;
+    }
+    if (append && !affectedValue.endsWith("\n")) {
+        affectedValue = `${affectedValue}\n`;
+    }
 
-	return affectedValue;
+    return affectedValue;
 }
 
 /**
@@ -159,29 +154,24 @@ function insertLf(value: string, prepend: boolean, append: boolean): string
  * @param ifKeyExists action if SSH key exists
  * @returns Yes/No
  */
-function shouldCreateKeyFile(keyFilePath: string, ifKeyExists: string): boolean
-{
-	if(!fs.existsSync(keyFilePath))
-	{
-		// should create if file does not exist
-		return true;
-	}
+function shouldCreateKeyFile(keyFilePath: string, ifKeyExists: string): boolean {
+    if (!fs.existsSync(keyFilePath)) {
+        // should create if file does not exist
+        return true;
+    }
 
-	switch(ifKeyExists)
-	{
-	case "replace":
-		// remove file and should create if replace
-		fs.unlinkSync(keyFilePath);
-		return true;
+    switch (ifKeyExists) {
+        case "replace":
+            // remove file and should create if replace
+            fs.unlinkSync(keyFilePath);
+            return true;
 
-	case "ignore":
-		// should NOT create if ignore
-		return false;
+        case "ignore":
+            // should NOT create if ignore
+            return false;
 
-	default:
-		// error otherwise
-		throw new Error(`SSH key is already installed. Set "if_key_exists" to "replace" or "ignore" in order to avoid this error.`);
-	}
+        default:
+            // error otherwise
+            throw new Error(`SSH key is already installed. Set "if_key_exists" to "replace" or "ignore" in order to avoid this error.`);
+    }
 }
-
-main();