test: align on using log appender in tests and some cleanup

Author: matrei

grails-core/build.gradle

@@ -95,21 +95,20 @@ dependencies {
     api 'org.slf4j:jcl-over-slf4j'
 
     // Testing
-    testImplementation 'ch.qos.logback:logback-classic'
+    testImplementation 'ch.qos.logback:logback-classic' // Used for checking log output in tests
     testImplementation 'org.spockframework:spock-core'
 
     testRuntimeOnly 'net.bytebuddy:byte-buddy' // Required by Spock's mocking support
     testRuntimeOnly 'org.objenesis:objenesis' // Required by Spock for mocking classes without default constructor
 }
 
-TaskProvider<WriteProperties> writeProps = tasks.register('writeGrailsProperties', WriteProperties)
-writeProps.configure { WriteProperties it ->
-    it.destinationFile = project.layout.buildDirectory.file('grails.build.properties')
-    it.property('grails.version', project.version)
+def writeProps= tasks.register('writeGrailsProperties', WriteProperties) {
+    destinationFile = project.layout.buildDirectory.file('grails.build.properties')
+    property('grails.version', project.version)
 }
 
-tasks.named('processResources', ProcessResources).configure { ProcessResources it ->
-    it.from writeProps
+tasks.named('processResources', ProcessResources) {
+    from(writeProps)
 }
 
 apply {

grails-core/src/test/groovy/grails/plugins/DefaultGrailsPluginManagerSpec.groovy

@@ -18,16 +18,22 @@
  */
 package grails.plugins
 
+import ch.qos.logback.classic.Logger
+import ch.qos.logback.classic.spi.ILoggingEvent
+import ch.qos.logback.core.read.ListAppender
+import org.slf4j.LoggerFactory
+import spock.lang.Specification
+import spock.lang.Unroll
+
+import org.springframework.context.support.GenericApplicationContext
+import org.springframework.core.env.StandardEnvironment
+
 import grails.core.DefaultGrailsApplication
 import grails.core.GrailsApplication
 import org.apache.grails.core.plugins.DefaultPluginDiscovery
-import org.apache.grails.core.plugins.PluginInfo
 import org.apache.grails.core.plugins.PluginDiscovery
+import org.apache.grails.core.plugins.PluginInfo
 import org.apache.grails.core.plugins.PluginUtils
-import org.springframework.context.support.GenericApplicationContext
-import org.springframework.core.env.StandardEnvironment
-import spock.lang.Specification
-import spock.lang.Unroll
 
 /**
  * Test suite for DefaultGrailsPluginManager
@@ -61,7 +67,7 @@ class DefaultGrailsPluginManagerSpec extends Specification {
     @Unroll
     def "should return #pluginGrailsVersion as plugin grails version"() {
         given:
-        PluginInfo plugin = stubPluginWithGrailsVersion(pluginGrailsVersion)
+        def plugin = stubPluginWithGrailsVersion(pluginGrailsVersion)
 
         when:
         def version = plugin.getGrailsVersionRange()
@@ -71,13 +77,13 @@ class DefaultGrailsPluginManagerSpec extends Specification {
 
         where:
         pluginGrailsVersion | _
-        "3.3.10 > *"        | _
+        '3.3.10 > *'        | _
     }
 
     @Unroll
     def "it should check that plugin with grailsVersion=#pluginGrailsVersion is compatible with grails #grailsVersion"() {
         given:
-        PluginInfo plugin = stubPluginWithGrailsVersion(pluginGrailsVersion)
+        def plugin = stubPluginWithGrailsVersion(pluginGrailsVersion)
 
         when:
         def compatible = plugin.isGrailsVersionCompatible(grailsVersion)
@@ -87,83 +93,96 @@ class DefaultGrailsPluginManagerSpec extends Specification {
 
         where:
         grailsVersion    | pluginGrailsVersion        || expectedCompatible
-        "1.0"            | "3.3.1 > *"                || false
-        "2.5"            | "3.0.1"                    || false
-        "3.0.0"          | "3.3.10 > *"               || false
-        "3.3.10"         | "4.0.0 > *"                || false
-        "4.0.1"          | "3.0.0.BUILD-SNAPSHOT > *" || true
-        "4.0.1"          | "4.0.1"                    || true
-        "4.0.1"          | "3.0.1"                    || false
-        "4.0.1"          | "3.3.1 > *"                || true
-        "4.0.1"          | "3.3.10 > *"               || true
+        '1.0'            | '3.3.1 > *'                || false
+        '2.5'            | '3.0.1'                    || false
+        '3.0.0'          | '3.3.10 > *'               || false
+        '3.3.10'         | '4.0.0 > *'                || false
+        '4.0.1'          | '3.0.0.BUILD-SNAPSHOT > *' || true
+        '4.0.1'          | '4.0.1'                    || true
+        '4.0.1'          | '3.0.1'                    || false
+        '4.0.1'          | '3.3.1 > *'                || true
+        '4.0.1'          | '3.3.10 > *'               || true
 
         // Milestone, release candidate and snapshot versions on both the application and the plugin (#14058)
-        "7.0.0-M2"       | "7.0.0-M1 > *"             || true
-        "7.0.0-M1"       | "7.0.0-M2 > *"             || false
-        "7.0.0-RC1"      | "7.0.0-M1 > *"             || true
-        "7.0.0-M1"       | "7.0.0-RC1 > *"            || false
-        "7.0.0"          | "7.0.0-RC1 > *"            || true
-        "7.0.0-RC1"      | "7.0.0 > *"                || false
-        "7.0.0-SNAPSHOT" | "7.0.0-SNAPSHOT > *"       || true
-        "7.0.5-M1"       | "7.0.3 > *"                || true
-        "7.0.0-M1"       | "7.0.0-M1"                 || true
-        "7.0.0-M2"       | "7.0.0-M1"                 || false
+        '7.0.0-M2'       | '7.0.0-M1 > *'             || true
+        '7.0.0-M1'       | '7.0.0-M2 > *'             || false
+        '7.0.0-RC1'      | '7.0.0-M1 > *'             || true
+        '7.0.0-M1'       | '7.0.0-RC1 > *'            || false
+        '7.0.0'          | '7.0.0-RC1 > *'            || true
+        '7.0.0-RC1'      | '7.0.0 > *'                || false
+        '7.0.0-SNAPSHOT' | '7.0.0-SNAPSHOT > *'       || true
+        '7.0.5-M1'       | '7.0.3 > *'                || true
+        '7.0.0-M1'       | '7.0.0-M1'                 || true
+        '7.0.0-M2'       | '7.0.0-M1'                 || false
     }
 
     def "per-plugin loaded messages are DEBUG and a single INFO summary reports the load order"() {
         given: 'a discovery bean with two plugins registered in reverse of their load order'
         def gcl = new GroovyClassLoader()
         def alphaClass = gcl.parseClass('''
-class AlphaProbeGrailsPlugin {
-    def version = "1.0.0"
-}
-''')
+            class AlphaProbeGrailsPlugin {
+                def version = '1.0.0'
+            }
+        ''')
         def betaClass = gcl.parseClass('''
-class BetaProbeGrailsPlugin {
-    def version = "2.0.0"
-    def loadAfter = ['alphaProbe']
-}
-''')
-        def application = new DefaultGrailsApplication()
-        application.mainContext = new GenericApplicationContext()
-        def discovery = new DefaultPluginDiscovery(new Class<?>[]{betaClass, alphaClass})
-        discovery.loadPluginsFromClasspath = false
-
-        and: 'standard error is captured to observe slf4j-simple output'
-        def originalErr = System.err
-        def captured = new ByteArrayOutputStream()
-        System.setErr(new PrintStream(captured, true))
+            class BetaProbeGrailsPlugin {
+                def version = '2.0.0'
+                def loadAfter = ['alphaProbe']
+            }
+        ''')
+        def application = new DefaultGrailsApplication(mainContext: new GenericApplicationContext())
+        def discovery = new DefaultPluginDiscovery([betaClass, alphaClass] as Class<?>[]).tap {
+            loadPluginsFromClasspath = false
+        }
+
+        and: 'configure a logback appender to capture log messages'
+        def logger = LoggerFactory.getLogger(DefaultGrailsPluginManager) as Logger
+        def appender = new ListAppender<ILoggingEvent>().tap { start() }
+        logger.addAppender(appender)
 
         when:
         discovery.init(new StandardEnvironment())
-        def manager = new DefaultGrailsPluginManager(application, discovery)
-        manager.loadPlugins()
+        def manager = new DefaultGrailsPluginManager(application, discovery).tap {
+            loadPlugins()
+        }
 
         then: 'both plugins are loaded'
-        manager.getGrailsPlugin('alphaProbe') != null
-        manager.getGrailsPlugin('betaProbe') != null
+        with(manager) {
+            getGrailsPlugin('alphaProbe') != null
+            getGrailsPlugin('betaProbe') != null
+        }
 
         and: 'the per-plugin loaded-successfully messages are not emitted at INFO'
-        captured.toString().readLines()
-                .findAll { it.contains('loaded successfully') }
-                .every { !it.contains('INFO') }
+        appender.list
+                .findAll { it.formattedMessage.contains('loaded successfully') }
+                .every { it.level.toString() != 'INFO' }
 
         and: 'a single INFO summary line reports the plugins in load order'
-        def summaryLines = captured.toString().readLines()
-                .findAll { it.contains('Grails plugins in load order') }
+        def summaryLines = appender.list.findAll {
+            it.formattedMessage.contains('Grails plugins in load order')
+        }
         summaryLines.size() == 1
-        summaryLines[0].contains('INFO')
-        summaryLines[0].contains('Loaded 2 Grails plugins in load order: [alphaProbe (1.0.0), betaProbe (2.0.0)]')
+        with(summaryLines[0]) {
+            level.toString() == 'INFO'
+            formattedMessage.contains('Loaded 2 Grails plugins in load order: [alphaProbe (1.0.0), betaProbe (2.0.0)]')
+        }
 
         cleanup:
-        System.setErr(originalErr)
+        logger.detachAppender(appender)
+        appender.stop()
     }
 
-    PluginInfo stubPluginWithGrailsVersion(String grailsVersion) {
+    private static PluginInfo stubPluginWithGrailsVersion(String grailsVersion) {
         def gcl = new GroovyClassLoader()
-        return PluginUtils.createPluginInfo(gcl.parseClass("class ACustomGrailsPlugin {\n" +
-                "def version = \"1.0.0\"\n" +
-                "def grailsVersion = \"$grailsVersion\"\n" +
-                "}"), null, true)
+        PluginUtils.createPluginInfo(
+                gcl.parseClass("""
+                    class ACustomGrailsPlugin {
+                        def version = '1.0.0'
+                        def grailsVersion = "$grailsVersion"
+                    }
+                """),
+                null,
+                true
+        )
     }
 }