[Filtering] Add support for filtering classes like Maven plugin (#54)

This adds package filters similar to how the Maven plugin filters in its `<classes>` block. This supports ant-like patterns similar to how patterns filter.

Follows #53 which added similar support for `packages` filtering

Closes #16.

README.md

@@ -224,6 +224,30 @@ sourceSets {
 See [`PackageFilter` tests](src/test/groovy/org/assertj/generator/gradle/parameter/PackageFilter.groovy) for more
 examples.
 
+#### classes - `JavaClassPatternFilterable`
+
+Default: All classes
+
+Class filters can be used to include, or exclude individual patterns of fully-qualified class names to be generated.
+These filters use a
+similar pattern to `include`/`exclude` with `SourceSet`.
+
+```groovy
+sourceSets {
+  main {
+    assertJ {
+      classes {
+        include "org.example.**" // include *all* classes under `org.example` including sub-packages
+        exclude "org.example.Foo" // exclude class `org.example.Foo` specifically
+      }
+    }
+  }
+}
+```
+
+See [`ClassesFilter` tests](src/test/groovy/org/assertj/generator/gradle/parameter/ClassesFilter.groovy) for more
+examples.
+
 #### entryPoints - `EntryPointsGeneratorOptions`
 
 Default: Only generate "standard" assertion entrypoint

src/main/kotlin/org/assertj/generator/gradle/tasks/AssertJGenerationTask.kt

@@ -20,6 +20,7 @@ import org.assertj.assertions.generator.description.converter.ClassToClassDescri
 import org.assertj.assertions.generator.util.ClassUtil
 import org.assertj.generator.gradle.tasks.config.AssertJGeneratorExtension
 import org.assertj.generator.gradle.tasks.config.SerializedTemplate
+import org.assertj.generator.gradle.tasks.config.patterns.JavaClassPatternFilterable
 import org.assertj.generator.gradle.tasks.config.patterns.JavaPackageNamePatternFilterable
 import org.gradle.api.DefaultTask
 import org.gradle.api.file.ConfigurableFileCollection
@@ -83,6 +84,9 @@ open class AssertJGenerationTask @Inject internal constructor(
   @get:Input
   internal val hierarchical: Property<Boolean> = objects.property()
 
+  @get:Input
+  internal val classesFilterable: Property<JavaClassPatternFilterable> = objects.property()
+
   @get:Input
   internal val packagesFilterable: Property<JavaPackageNamePatternFilterable> = objects.property()
 
@@ -114,6 +118,7 @@ open class AssertJGenerationTask @Inject internal constructor(
 
     skip.set(project.provider { assertJOptions.skip })
     hierarchical.set(project.provider { assertJOptions.hierarchical })
+    classesFilterable.set(project.provider { assertJOptions.classes })
     packagesFilterable.set(project.provider { assertJOptions.packages })
     entryPoints.set(project.provider { assertJOptions.entryPoints.entryPoints })
     entryPointsClassPackage.set(project.provider { assertJOptions.entryPoints.classPackage })
@@ -130,6 +135,7 @@ open class AssertJGenerationTask @Inject internal constructor(
 
     val classLoader = URLClassLoader((generationClasspath + classDirectories).map { it.toURI().toURL() }.toTypedArray())
 
+    val classesPredicate = classesFilterable.get().asPredicate()
     val packagesPredicate = packagesFilterable.get().asPredicate()
     val allClassNames = getClassNames(classDirectories)
       .filter { packagesPredicate.test(it.substringBeforeLast('.')) }
@@ -138,7 +144,9 @@ open class AssertJGenerationTask @Inject internal constructor(
     val allClasses = ClassUtil.collectClasses(
       classLoader,
       *allClassNames.toTypedArray(),
-    )
+    ).asSequence()
+      .filter { classesPredicate.test(it) }
+      .toSet()
 
     val changedFiles = if (inputs.isIncremental) {
       inputs.getFileChanges(classDirectories).asSequence().map { it.file }.filter { it.isFile }.toSet()

src/main/kotlin/org/assertj/generator/gradle/tasks/config/AssertJGeneratorExtension.kt

@@ -13,6 +13,7 @@
 package org.assertj.generator.gradle.tasks.config
 
 import org.assertj.assertions.generator.AssertionsEntryPointType
+import org.assertj.generator.gradle.tasks.config.patterns.JavaClassPatternFilterable
 import org.assertj.generator.gradle.tasks.config.patterns.JavaPackageNamePatternFilterable
 import org.gradle.api.Action
 import org.gradle.api.Project
@@ -35,6 +36,12 @@ open class AssertJGeneratorExtension @Inject internal constructor(
   val classDirectories: SourceDirectorySet =
     objects.sourceDirectorySet("assertJClasses", "Classes to generate AssertJ assertions from")
 
+  val classes: JavaClassPatternFilterable = objects.newInstance()
+
+  fun classes(action: Action<in JavaClassPatternFilterable>): AssertJGeneratorExtension = apply {
+    action.execute(classes)
+  }
+
   val packages: JavaPackageNamePatternFilterable = objects.newInstance()
 
   fun packages(action: Action<in JavaPackageNamePatternFilterable>): AssertJGeneratorExtension = apply {

src/main/kotlin/org/assertj/generator/gradle/tasks/config/patterns/JavaClassPatternFilterable.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2023. assertj-generator-gradle-plugin contributors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package org.assertj.generator.gradle.tasks.config.patterns
+
+import com.google.common.reflect.TypeToken
+import org.assertj.generator.gradle.tasks.config.patterns.JavaNamePatternCompiler.compilePattern
+import java.io.IOException
+import java.io.ObjectInputStream
+import java.io.ObjectOutputStream
+import java.io.Serializable
+
+/**
+ * Implements a similar construction to [org.gradle.api.tasks.util.PatternFilterable] that will match
+ * [TypeToken] instances.
+ */
+open class JavaClassPatternFilterable internal constructor() :
+  JavaIdentifierNamePatternFilterableBase<TypeToken<*>, JavaClassPatternFilterable>(), Serializable {
+
+  override fun compilePatterns(patterns: Iterable<String>): Sequence<PatternPredicate<TypeToken<*>>> {
+    return patterns.asSequence().map { TypeNamePredicate.compile(it) }
+  }
+
+  @Throws(IOException::class)
+  protected fun writeObject(o: ObjectOutputStream) {
+    super.writeObjectImpl(o)
+  }
+
+  @Throws(IOException::class, ClassNotFoundException::class)
+  protected fun readObject(i: ObjectInputStream) {
+    super.readObjectImpl(i)
+  }
+
+  internal data class TypeNamePredicate(
+    override val pattern: String,
+    private val namePattern: Regex,
+  ) : PatternPredicate<TypeToken<*>> {
+    override fun test(t: TypeToken<*>): Boolean {
+      return namePattern.matches(t.type.typeName)
+    }
+
+    companion object {
+      fun compile(pattern: String): TypeNamePredicate = TypeNamePredicate(pattern, compilePattern(pattern))
+    }
+  }
+
+  companion object {
+    private const val serialVersionUID = 9418631994L
+  }
+}