Fail build on failure

.appveyor.yml

@@ -47,6 +47,8 @@ init:
 ## Install PHP and composer, and run the appropriate composer command
 install:
     - ps: |
+        $ErrorActionPreference = "Stop"
+
         # Check if installation is cached
         if (!(Test-Path c:\tools\php)) {
           appveyor-retry cinst --params '""/InstallDir:C:\tools\php""' --ignore-checksums -y php --version ((choco search php --exact --all-versions -r | select-string -pattern $env:php | sort { [version]($_ -split '\|' | select -last 1) } -Descending | Select-Object -first 1) -replace '[php|]','')
@@ -125,23 +127,25 @@ install:
 before_test:
 # Selectively start the services
   - ps: >-
+      $ErrorActionPreference = "Stop"
+
       if ($env:db -eq "mssql") {
         $instanceName = $env:db_version.ToUpper()
         net start "MSSQL`$$instanceName"
       }
 
 test_script:
   - cd C:\projects\dbal
-  - ps: >-
-      if ($env:db_version) {
-        $env:phpunit_config = "tests\appveyor\$($env:db).$($env:db_version).$($env:driver).appveyor.xml"
-      } else {
-        $env:phpunit_config = "tests\appveyor\$($env:db).$($env:driver).appveyor.xml"
-      }
-  - ps: >-
-      if ($env:coverage -eq "yes") {
-        vendor\bin\phpunit -c $($env:phpunit_config) --coverage-clover clover.xml
-        appveyor-retry ocular code-coverage:upload --format=php-clover clover.xml
-      } else {
-        vendor\bin\phpunit -c $($env:phpunit_config)
-      }
+  - cmd: >-
+      if defined db_version (
+          set "phpunit_config=tests\appveyor\%db%.%db_version%.%driver%.appveyor.xml"
+      ) else (
+          set "phpunit_config=tests\appveyor\%db%.%driver%.appveyor.xml"
+      )
+
+      if defined coverage (
+          vendor\bin\phpunit -c %phpunit_config% --coverage-clover clover.xml || exit /b
+          appveyor-retry ocular code-coverage:upload --format=php-clover clover.xml
+      ) else (
+          vendor\bin\phpunit -c %phpunit_config%
+      )