feat: add support for running on windows and macos

.github/workflows/reviewdog.yml

@@ -3,7 +3,10 @@ on: [pull_request]
 jobs:
   shellcheck:
     name: runner / shellcheck
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
       - uses: actions/checkout@v3
       - name: shellcheck-github-pr-check

script.sh

@@ -5,9 +5,23 @@ set -u
 echo '::group:: Installing shellcheck ... https://github.com/koalaman/shellcheck'
 TEMP_PATH="$(mktemp -d)"
 cd "${TEMP_PATH}" || exit
-curl -sL "https://github.com/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/shellcheck-v${SHELLCHECK_VERSION}.linux.x86_64.tar.xz" | tar -xJf -
 mkdir bin
-cp "shellcheck-v$SHELLCHECK_VERSION/shellcheck" ./bin
+
+WINDOWS_TARGET=zip
+LINUX_TARGET=linux.x86_64.tar.xz
+MACOS_TARGET=darwin.x86_64.tar.xz
+
+if [[ $(uname -s) == "Linux" ]]; then
+    curl -sL "https://github.com/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/shellcheck-v${SHELLCHECK_VERSION}.${LINUX_TARGET}" | tar -xJf -
+    cp "shellcheck-v$SHELLCHECK_VERSION/shellcheck" ./bin
+elif [[ $(uname -s) == "Darwin" ]]; then
+    curl -sL "https://github.com/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/shellcheck-v${SHELLCHECK_VERSION}.${MACOS_TARGET}" | tar -xJf -
+    cp "shellcheck-v$SHELLCHECK_VERSION/shellcheck" ./bin
+else
+    curl -sL "https://github.com/koalaman/shellcheck/releases/download/v${SHELLCHECK_VERSION}/shellcheck-v${SHELLCHECK_VERSION}.${WINDOWS_TARGET}" -o "shellcheck-v${SHELLCHECK_VERSION}.${WINDOWS_TARGET}" && unzip "shellcheck-v${SHELLCHECK_VERSION}.${WINDOWS_TARGET}" && rm "shellcheck-v${SHELLCHECK_VERSION}.${WINDOWS_TARGET}"
+    cp "shellcheck.exe" ./bin
+fi
+
 PATH="${TEMP_PATH}/bin:$PATH"
 echo '::endgroup::'