CI: GitHub Actions on Windows setup

Closes #112

.github/workflows/ci-windows.yml

@@ -0,0 +1,66 @@
+name: "FileCheck.py on Windows"
+
+on: [pull_request]
+
+jobs:
+  build:
+    runs-on: windows-latest
+
+    strategy:
+      matrix:
+        python-version: [3.5, 3.6, 3.7, 3.8]
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Upgrade pip
+      run: |
+        python -m pip install --upgrade pip
+
+    - name: Install Poetry
+      run: |
+        (Invoke-WebRequest -Uri https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py -UseBasicParsing).Content | python
+
+    - name: "Poetry: add to %PATH%"
+      run: |
+        echo "::add-path::$env:USERPROFILE\.poetry\bin"
+
+    - name: "Print PATH"
+      run: |
+        echo $env:USERPROFILE
+        echo $env:PATH
+
+    - name: "Print PWD"
+      run: |
+        echo "$PWD"
+
+    - name: "WIP: type"
+      run: |
+        type "D:/a/FileCheck.py/FileCheck.py/tests/i/filecheck.iii"
+        type "D:/a/FileCheck.py/FileCheck.py/tests/i/filecheck.iii" | echo
+        type "D:/a/FileCheck.py/FileCheck.py/tests/i/tests/check_commands/CHECK-EMPTY/01-error_CHECK_EMPTY_without_previous_CHECK/filecheck.input"
+        type "D:/a/FileCheck.py/FileCheck.py/tests/i/tests/check_commands/CHECK-EMPTY/01-error_CHECK_EMPTY_without_previous_CHECK/filecheck.input" | echo
+        python --version
+        $psversiontable
+
+    - name: "Poetry: print version"
+      run: |
+        poetry --version
+
+    - name: "Poetry: configure settings"
+      run: |
+        poetry config virtualenvs.in-project true
+
+    - name: "Poetry: Install dependencies"
+      run: |
+        poetry install
+
+    - name: Run tests
+      run: |
+        poetry run invoke test
+      shell: powershell

tests/integration/lit.cfg

@@ -25,7 +25,8 @@ real_only = lit_config.params['REAL_ONLY']
 config.substitutions.append(('%FILECHECK_EXEC', filecheck_exec))
 config.substitutions.append(('%FILECHECK_TESTER_EXEC', filecheck_tester_exec))
 
-cat_exec = "cat" if not is_windows() else "type"
+shell = os.environ.get('SHELL', '')
+cat_exec = "cat" if (not is_windows() or shell == "/bin/bash") else "type"
 config.substitutions.append(('%cat', cat_exec))
 
 config.substitutions.append(('%expect_exit', 'python \"{}/tests/integration/tools/expect_exit.py\"'.format(current_dir)))