Convert Log4j2PluginsCacheFileTransformerTest

src/test/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/Log4j2PluginsCacheFileTransformerTest.kt

@@ -0,0 +1,68 @@
+package com.github.jengelman.gradle.plugins.shadow.transformers
+
+import assertk.assertThat
+import assertk.assertions.isEqualTo
+import assertk.assertions.isTrue
+import com.github.jengelman.gradle.plugins.shadow.relocation.SimpleRelocator
+import java.io.File
+import java.io.FileNotFoundException
+import java.io.InputStream
+import java.net.URL
+import java.util.Collections
+import org.apache.logging.log4j.core.config.plugins.processor.PluginCache
+import org.apache.tools.zip.ZipOutputStream
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+
+class Log4j2PluginsCacheFileTransformerTest : TransformerTestSupport<Log4j2PluginsCacheFileTransformer>() {
+
+  @BeforeEach
+  fun setup() {
+    transformer = Log4j2PluginsCacheFileTransformer()
+  }
+
+  @Test
+  fun `should transform for a single file`() {
+    transformer.transform(TransformerContext(PLUGIN_CACHE_FILE, getResourceStream()))
+    assertThat(transformer.hasTransformedResource()).isTrue()
+  }
+
+  @Test
+  fun `should transform`() {
+    val relocators = listOf(SimpleRelocator())
+    transformer.transform(TransformerContext(PLUGIN_CACHE_FILE, getResourceStream(), relocators))
+    assertThat(transformer.hasTransformedResource()).isTrue()
+  }
+
+  @Test
+  fun `relocate classes inside DAT file`() {
+    val pattern = "org.apache.logging"
+    val destination = "new.location.org.apache.logging"
+    val relocators = listOf(SimpleRelocator(pattern, destination))
+
+    transformer.transform(TransformerContext(PLUGIN_CACHE_FILE, getResourceStream(), relocators))
+    assertThat(transformer.hasTransformedResource()).isTrue()
+
+    // Write out to a fake jar file
+    val testableZipFile = File.createTempFile("testable-zip-file-", ".jar")
+    val zipOutputStream = ZipOutputStream(testableZipFile.outputStream().buffered())
+    transformer.modifyOutputStream(zipOutputStream, true)
+    zipOutputStream.close()
+
+    // Pull the data back out and make sure it was transformed
+    val cache = PluginCache()
+    val urlString = "jar:" + testableZipFile.toURI().toURL() + "!/" + PLUGIN_CACHE_FILE
+    cache.loadCacheFiles(Collections.enumeration(listOf(URL(urlString))))
+
+    assertThat(cache.getCategory("lookup")["date"]?.className)
+      .isEqualTo("new.location.org.apache.logging.log4j.core.lookup.DateLookup")
+  }
+
+  private fun getResourceStream(resource: String = PLUGIN_CACHE_FILE): InputStream {
+    return this::class.java.classLoader.getResourceAsStream(resource) ?: throw FileNotFoundException("Resource not found: $resource")
+  }
+
+  companion object {
+    private const val PLUGIN_CACHE_FILE = "META-INF/org/apache/logging/log4j/core/config/plugins/Log4j2Plugins.dat"
+  }
+}