Add Code Coverage reports in Merge Requests

Motivation:

To maintain quality, automated code coverage reports should be generated and archived as build artifacts in CI pipelines.

Modifications:

Update CI config to run a job for running unit tests with code coverage, and exporting the report to GitLab.

Result:

Code coverage will be tracked and history recorded to compare individual code changes.

Author: Mordil

.gitlab/ci/main.yml

@@ -1,3 +1,5 @@
+include: '/.gitlab/ci/platform-test.yml'
+
 stages:
   - Platform Tests
   - Quality Checks
@@ -27,6 +29,18 @@ Code Climate:
     reports:
       codequality: gl-code-quality-report.json
 
+Code Coverage:
+  extends: .platform-test
+  stage: Quality Checks
+  allow_failure: false
+  image: swift:latest
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
+      changes:
+        - '*.swift'
+  script: scripts/generate_code_coverage.sh
+  coverage: '/TOTAL.*(\s\d+\.\d+%)/'
+
 .standard-platform-test:
   rules:
     - if: $CI_PIPELINE_SOURCE == "push"

README.md

@@ -9,7 +9,8 @@
 </p>
 
 <p>
-    <a href="https://gitlab.com/Mordil/RediStack/pipelines"><img src="https://gitlab.com/Mordil/RediStack/badges/master/pipeline.svg" alt="Build Status"></a>
+    <a href="https://gitlab.com/Mordil/RediStack/-/commits/master"><img alt="pipeline status" src="https://gitlab.com/Mordil/RediStack/badges/master/pipeline.svg" /></a>
+    <a href="https://gitlab.com/Mordil/RediStack/-/commits/master"><img alt="coverage report" src="https://gitlab.com/Mordil/RediStack/badges/master/coverage.svg"/></a>
     <a href="https://swiftpackageindex.com/Mordil/RediStack/master/documentation/redistack"><img src="https://img.shields.io/badge/SPI-Documentation-blue.svg" alt="Documentation Coverage"></a>
     <a href="https://codeclimate.com/github/Mordil/RediStack/maintainability"><img src="https://api.codeclimate.com/v1/badges/b6fd5e7a3e669165a21b/maintainability" /></a>
 </p>

scripts/generate_code_coverage.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the RediStack open source project
+##
+## Copyright (c) 2022 RediStack project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of RediStack project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
+
+swift test --enable-code-coverage --enable-test-discovery
+
+BUILD_BIN_PATH=$(swift build --show-bin-path)
+CODE_COV_PATH=$(swift test --show-codecov-path)
+
+PROF_DATA_PATH="${CODE_COV_PATH%/*}/default.profdata"
+TEST_BINARY_PATH="${BUILD_BIN_PATH}/RediStackPackageTests.xctest"
+
+IGNORE_FILENAME_REGEX="(\.build|TestUtils|Tests)"
+
+llvm-cov report \
+    $TEST_BINARY_PATH \
+    --format=text \
+    --instr-profile="$PROF_DATA_PATH" \
+    --ignore-filename-regex="$IGNORE_FILENAME_REGEX"