[ci] move Windows Python jobs to GitHub Actions

.ci/download-artifacts.sh

@@ -12,14 +12,11 @@
 #     The following are not yet handled by this script.
 #
 #         - commit.txt
-#         - lib_lightgbm.dll
 #         - lib_lightgbm.so
 #         - lightgbm-4.6.0-py3-none-manylinux_2_28_x86_64.whl
-#         - lightgbm-4.6.0-py3-none-win_amd64.whl
 #         - lightgbm-4.6.0.tar.gz
 #         - LightGBM-complete_source_code_tar_gz.tar.gz
 #         - LightGBM.4.6.0.nupkg
-#         - lightgbm.exe
 #
 
 set -e -u -E -o pipefail

.ci/test-windows.ps1

@@ -66,10 +66,13 @@ if ($env:TASK -eq "swig") {
 }
 
 # setup for Python
-conda init powershell
-conda activate
-conda config --set always_yes yes --set changeps1 no
-conda install -q -y conda "python=$env:PYTHON_VERSION[build=*_cp*]"
+conda activate ; Assert-Output $?
+conda config --set always_yes yes --set changeps1 no ; Assert-Output $?
+conda config --remove channels defaults ; Assert-Output $?
+conda config --add channels nodefaults ; Assert-Output $?
+conda config --add channels conda-forge ; Assert-Output $?
+conda config --set channel_priority strict ; Assert-Output $?
+conda install -q -y conda "python=$env:PYTHON_VERSION[build=*_cp*]" ; Assert-Output $?
 
 # print output of 'conda info', to help in submitting bug reports
 Write-Output "conda info:"
@@ -141,7 +144,7 @@ if (($env:TASK -eq "sdist") -or (($env:APPVEYOR -eq "true") -and ($env:TASK -eq
 if ($env:TASK -eq "bdist") {
     # Make sure we can do both CPU and GPU; see tests/python_package_test/test_dual.py
     # TODO: set LIGHTGBM_TEST_DUAL_CPU_GPU back to "1" as part of https://github.com/microsoft/LightGBM/issues/6968
-    env:LIGHTGBM_TEST_DUAL_CPU_GPU = "0"
+    $env:LIGHTGBM_TEST_DUAL_CPU_GPU = "0"
 }
 
 pytest $tests ; Assert-Output $?

.github/workflows/python_package.yml

@@ -17,6 +17,8 @@ env:
   # tell scripts where to put artifacts
   # (this variable name is left over from when jobs ran on Azure DevOps)
   BUILD_ARTIFACTSTAGINGDIRECTORY: '${{ github.workspace }}/artifacts'
+  # where repo sources are cloned to
+  BUILD_SOURCESDIRECTORY: '${{ github.workspace }}'
   CMAKE_BUILD_PARALLEL_LEVEL: 4
   SKBUILD_STRICT_CONFIG: true
 
@@ -69,7 +71,7 @@ jobs:
         with:
           name: linux-aarch64-wheel
           path: artifacts/*.whl
-  test-macos:
+  test:
     # yamllint disable-line rule:line-length
     name: ${{ matrix.task }} ${{ matrix.method }} (${{ matrix.os }}, ${{ matrix.compiler }}, Python ${{ matrix.python_version }})
     runs-on: ${{ matrix.os }}
@@ -94,6 +96,13 @@ jobs:
             task: bdist
             compiler: gcc
             python_version: '3.9'
+          - os: windows-2022
+            task: sdist
+            compiler: MSVC
+            python_version: '3.10'
+          ############
+          # MPI jobs #
+          ############
           - os: macos-15-intel
             task: mpi
             compiler: gcc
@@ -133,14 +142,28 @@ jobs:
             produces-artifacts: 'true'
             artifact-name: 'macosx-amd64-liblightgbm'
             python_version: '3.11'
+          - os: windows-2022
+            task: bdist
+            compiler: MSVC
+            method: wheel
+            produces-artifacts: 'true'
+            artifact-name: 'windows-amd64-wheel'
+            python_version: '3.13'
+          - os: windows-2022
+            task: regular
+            compiler: MSVC
+            produces-artifacts: 'true'
+            artifact-name: 'windows-amd64-cli-and-liblightgbm'
+            python_version: '3.11'
     steps:
       - name: Checkout repository
         uses: actions/checkout@v5
         with:
           fetch-depth: 5
           persist-credentials: false
           submodules: true
-      - name: Setup and run tests
+      - name: Setup and run tests on Linux and macOS
+        if: startsWith(matrix.os, 'macos') || startsWith(matrix.os, 'ubuntu')
         shell: bash
         run: |
           export COMPILER="${{ matrix.compiler }}"
@@ -154,14 +177,39 @@ jobs:
           export PRODUCES_ARTIFACTS="${{ matrix.produces-artifacts }}"
           $GITHUB_WORKSPACE/.ci/setup.sh || exit 1
           $GITHUB_WORKSPACE/.ci/test.sh || exit 1
+      - name: Install OpenCL on Windows
+        if: startsWith(matrix.os, 'windows') && (matrix.task == 'bdist')
+        shell: pwsh -command ". {0}"
+        run: |
+          & "$env:GITHUB_WORKSPACE/.ci/install-opencl.ps1"
+      # 'conda init powershell' needs to be run in a separate process
+      # ref: https://docs.conda.io/projects/conda/en/stable/dev-guide/deep-dives/activation.html
+      - name: Initialize conda on Windows
+        if: startsWith(matrix.os, 'windows')
+        shell: pwsh -command ". {0}"
+        run: |
+          $env:PATH = "$env:CONDA/Scripts;$env:PATH"
+          conda init powershell
+      - name: Setup and run tests on Windows
+        if: startsWith(matrix.os, 'windows')
+        shell: pwsh -command ". {0}"
+        run: |
+          $env:COMPILER = "${{ matrix.compiler }}"
+          $env:METHOD = "${{ matrix.method }}"
+          $env:PRODUCES_ARTIFACTS = "${{ matrix.produces-artifacts }}"
+          $env:PYTHON_VERSION = "${{ matrix.python_version }}"
+          $env:TASK = "${{ matrix.task }}"
+          & "$env:GITHUB_WORKSPACE/.ci/test-windows.ps1"
       - name: Upload artifacts
         if: ${{ matrix.produces-artifacts == 'true' }}
         uses: actions/upload-artifact@v5
         with:
           name: ${{ matrix.artifact-name }}
           path: |
-            artifacts/*.whl
+            artifacts/*.dll
             artifacts/*.dylib
+            artifacts/*.exe
+            artifacts/*.whl
           if-no-files-found: error
   test-latest-versions:
     name: Python - latest versions (ubuntu-latest)
@@ -231,7 +279,7 @@ jobs:
     runs-on: ubuntu-latest
     needs:
       - test-latest-versions
-      - test-macos
+      - test
       - test-linux-aarch64
       - test-old-versions
     steps:

.vsts-ci.yml

@@ -203,52 +203,6 @@ jobs:
         inputs:
           filePath: $(Build.SourcesDirectory)/.ci/test.sh
           targetType: 'filePath'
-  ###########
-  # Windows #
-  ###########
-  - job: Windows
-    pool:
-      vmImage: 'windows-2022'
-    strategy:
-      matrix:
-        regular:
-          TASK: regular
-          PYTHON_VERSION: '3.11'
-        sdist:
-          TASK: sdist
-          PYTHON_VERSION: '3.10'
-        bdist:
-          TASK: bdist
-    steps:
-      - powershell: |
-          Write-Host "##vso[task.prependpath]$env:CONDA\Scripts"
-        displayName: 'Set Variables'
-      - script: |
-          git clean -d -f -x
-        displayName: 'Clean source directory'
-      - script: |
-          cmd /c "powershell -ExecutionPolicy Bypass -File %BUILD_SOURCESDIRECTORY%/.ci/install-opencl.ps1"
-        condition: eq(variables['TASK'], 'bdist')
-        displayName: 'Install OpenCL'
-      - script: |
-          cmd /c "conda config --remove channels defaults"
-          cmd /c "conda config --add channels nodefaults"
-          cmd /c "conda config --add channels conda-forge"
-          cmd /c "conda config --set channel_priority strict"
-          cmd /c "conda init powershell"
-          cmd /c "powershell -ExecutionPolicy Bypass -File %BUILD_SOURCESDIRECTORY%/.ci/test-windows.ps1"
-        displayName: Test
-      - task: PublishBuildArtifacts@1
-        condition: >
-          and(
-          succeeded(),
-          in(variables['TASK'], 'regular', 'bdist'),
-          not(startsWith(variables['Build.SourceBranch'], 'refs/pull/'))
-          )
-        inputs:
-          pathtoPublish: '$(Build.ArtifactStagingDirectory)'
-          artifactName: PackageAssets
-          artifactType: container
 
   ###########
   # Package #
@@ -257,7 +211,6 @@ jobs:
     dependsOn:
       - Linux
       - Linux_latest
-      - Windows
     condition: and(succeeded(), not(startsWith(variables['Build.SourceBranch'], 'refs/pull/')))
     pool:
       vmImage: 'ubuntu-22.04'

tests/python_package_test/test_dual.py

@@ -13,8 +13,8 @@
 
 
 @pytest.mark.skipif(
-    os.environ.get("LIGHTGBM_TEST_DUAL_CPU_GPU", None) is None,
-    reason="Only run if appropriate env variable is set",
+    os.environ.get("LIGHTGBM_TEST_DUAL_CPU_GPU", "0") != "1",
+    reason="Set LIGHTGBM_TEST_DUAL_CPU_GPU=1 to test using CPU and GPU training from the same package.",
 )
 def test_cpu_and_gpu_work():
     # If compiled appropriately, the same installation will support both GPU and CPU.