[ci] attach archives with complete source code of the repo to releases (#4111)

* attach archives with complete source code of the repo to releases

* restore missed conditions

.vsts-ci.yml

@@ -288,6 +288,26 @@ jobs:
   pool:
     vmImage: 'ubuntu-latest'
   steps:
+  # Create archives with complete source code included (with git submodules)
+  - task: ArchiveFiles@2
+    displayName: Create zip archive
+    condition: and(succeeded(), startsWith(variables['Build.SourceBranch'], 'refs/tags/v'))
+    inputs:
+      rootFolderOrFile: $(Build.SourcesDirectory)
+      includeRootFolder: false
+      archiveType: zip
+      archiveFile: '$(Build.ArtifactStagingDirectory)/archives/LightGBM-complete_source_code_zip.zip'
+      replaceExistingArchive: true
+  - task: ArchiveFiles@2
+    displayName: Create tar.gz archive
+    condition: and(succeeded(), startsWith(variables['Build.SourceBranch'], 'refs/tags/v'))
+    inputs:
+      rootFolderOrFile: $(Build.SourcesDirectory)
+      includeRootFolder: false
+      archiveType: tar
+      tarCompression: gz
+      archiveFile: '$(Build.ArtifactStagingDirectory)/archives/LightGBM-complete_source_code_tar_gz.tar.gz'
+      replaceExistingArchive: true
   # Download all agent packages from all previous phases
   - task: DownloadBuildArtifacts@0
     displayName: Download package assets
@@ -301,10 +321,10 @@ jobs:
     inputs:
       command: pack
       packagesToPack: '$(Build.SourcesDirectory)/.nuget/*.nuspec'
-      packDestination: '$(Build.ArtifactStagingDirectory)'
+      packDestination: '$(Build.ArtifactStagingDirectory)/nuget'
   - task: PublishBuildArtifacts@1
     inputs:
-      pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+      pathtoPublish: '$(Build.ArtifactStagingDirectory)/nuget'
       artifactName: NuGet
       artifactType: container
   - task: GitHubRelease@0
@@ -319,7 +339,8 @@ jobs:
       title: '$(Build.SourceBranchName)'
       assets: |
         $(Build.SourcesDirectory)/binaries/PackageAssets/*
-        $(Build.ArtifactStagingDirectory)/*.nupkg
+        $(Build.ArtifactStagingDirectory)/nuget/*.nupkg
+        $(Build.ArtifactStagingDirectory)/archives/*
       assetUploadMode: 'delete'
       isDraft: true
       isPreRelease: false