Setup code coverage in Azure DevOps

Author: andyleejordan

.vsts-ci/azure-pipelines-ci.yml

@@ -53,6 +53,16 @@ jobs:
     vmImage: macOS-10.15
   steps:
   - template: templates/ci-general.yml
+  # NOTE: The coverage tooling only works consistently on macOS.
+  - pwsh: npm run coverage
+    workingDirectory: $(Build.SourcesDirectory)/vscode-powershell
+    displayName: Analyzing code coverage
+  - task: PublishCodeCoverageResults@1
+    displayName: Publish code coverage results
+    inputs:
+      codeCoverageTool: Cobertura
+      summaryFileLocation: $(Build.SourcesDirectory)/vscode-powershell/coverage/cobertura-coverage.xml
+      failIfCoverageEmpty: true
 
 - job: PS7_Ubuntu
   displayName: PowerShell 7 - Ubuntu 20.04