Fix build jobs: self-contained restore (drop --no-restore/--no-build), add NuGet cache

# GitLab CI/CD component to restore, build, test and publish .NET Core / .NET projects.

# GitLab CI/CD component to build, test and publish .NET Core / .NET projects.

#

# Reference: https://docs.gitlab.com/ee/ci/components/

#

#         tests_enabled: true

#

# All jobs run in the official .NET SDK image `mcr.microsoft.com/dotnet/sdk`.

# Every job performs its own restore+build so it works from a clean checkout

# (the repository must NOT contain committed `obj/` / `bin/` folders).

spec:

  inputs:

    # .NET SDK version (major.minor) used as the image tag.

    dotnet_version:

      default: "8.0"

    # The MsBuild configuration to restore/build/publish with.

    # The MsBuild configuration to build/publish with.

    configuration:

      default: Release

    # Glob path to the .sln / .csproj to build. Leave empty to build the default

    # project found in the repository root.

    solution_path:

      default: ""

    # Set to "true" to enable the test job. The test command targets the restored

    # solution unless `test_project_path` is provided.

    # Set to "true" to enable the test job.

    tests_enabled:

      default: false

    # Set to "true" to enable the publish job.

  RUN_TESTS: "$[[ inputs.tests_enabled ]]"

  ENABLE_PUBLISH: "$[[ inputs.publish_enabled ]]"

  PUBLISH_OUTPUT: "$[[ inputs.publish_output ]]"

  # Keep the NuGet package cache inside the project dir so jobs share it.

  NUGET_PACKAGES: "$CI_PROJECT_DIR/.nuget/packages"

# Restore NuGet packages. Skipped automatically if `solution_path` is empty.

dotnet-restore:

  image: "mcr.microsoft.com/dotnet/sdk:$DOTNET_VERSION"

  stage: $[[ inputs.stage ]]

  variables:

    NUGET_RESTORE_ARGS: "$[[ inputs.solution_path ]]"

  script:

    - if [ -z "$NUGET_RESTORE_ARGS" ]; then echo "No solution/project specified, skipping restore." && exit 0; fi

    - dotnet restore "$NUGET_RESTORE_ARGS" -p:Configuration="$BUILD_CONFIGURATION"

  rules:

    - if: $CI_PIPELINE_SOURCE == "merge_request_event"

    - if: $CI_COMMIT_BRANCH && $CI_OPEN_MERGE_REQUESTS

      when: never

    - when: always

# Share restored NuGet packages across the parallel jobs of a pipeline.

cache:

  key: "nuget-$DOTNET_VERSION-$CI_COMMIT_REF_SLUG"

  paths:

    - ".nuget/packages"

# Compile the solution/project and keep the build output as an artifact.

dotnet-build:

  variables:

    DOTNET_BUILD_ARGS: "$[[ inputs.solution_path ]]"

  script:

    - dotnet build "$DOTNET_BUILD_ARGS" -p:Configuration="$BUILD_CONFIGURATION" --no-restore

    - if [ -z "$DOTNET_BUILD_ARGS" ]; then echo "No solution/project specified, skipping build." && exit 0; fi

    - dotnet build "$DOTNET_BUILD_ARGS" -p:Configuration="$BUILD_CONFIGURATION"

  artifacts:

    paths:

      - "**/bin/$BUILD_CONFIGURATION/**"

  variables:

    DOTNET_TEST_ARGS: "$[[ inputs.solution_path ]]"

  script:

    - dotnet test "$DOTNET_TEST_ARGS" -p:Configuration="$BUILD_CONFIGURATION" --no-restore --no-build

    - if [ -z "$DOTNET_TEST_ARGS" ]; then echo "No solution/project specified, skipping tests." && exit 0; fi

    - dotnet test "$DOTNET_TEST_ARGS" -p:Configuration="$BUILD_CONFIGURATION"

  artifacts:

    when: always

    reports:

  variables:

    DOTNET_PUBLISH_ARGS: "$[[ inputs.solution_path ]]"

  script:

    - dotnet publish "$DOTNET_PUBLISH_ARGS" -p:Configuration="$BUILD_CONFIGURATION" --no-restore --no-build --output "$PUBLISH_OUTPUT"

    - if [ -z "$DOTNET_PUBLISH_ARGS" ]; then echo "No solution/project specified, skipping publish." && exit 0; fi

    - dotnet publish "$DOTNET_PUBLISH_ARGS" -p:Configuration="$BUILD_CONFIGURATION" --output "$PUBLISH_OUTPUT"

  artifacts:

    paths:

      - "$PUBLISH_OUTPUT/**"