always generate log file

demo/kotlin-demo/src/main/kotlin/com/alibaba/demo/java2kotlin/PathDemo.kt

@@ -3,7 +3,7 @@ package com.alibaba.demo.java2kotlin
 import java.io.File
 import java.io.IOException
 
-object PathUtil {
+object PathDemo {
 
     fun deleteRecursively(file: File) {
         if (!file.exists()) {

demo/kotlin-demo/src/test/kotlin/com/alibaba/demo/java2kotlin/PathDemoTest.kt

@@ -5,7 +5,7 @@ import com.alibaba.testable.core.matcher.InvokeVerifier.verify
 import org.junit.jupiter.api.Test
 import java.io.File
 
-class PathUtilTest {
+class PathDemoTest {
 
     class Mock {
         @MockMethod
@@ -42,7 +42,7 @@ class PathUtilTest {
 
     @Test
     fun should_mock_java_method_invoke_in_kotlin() {
-        PathUtil.deleteRecursively(File("/a/b/"))
+        PathDemo.deleteRecursively(File("/a/b/"))
         verify("listFiles").withTimes(2)
         verify("delete").withTimes(4)
     }

testable-agent/src/main/java/com/alibaba/testable/agent/PreMain.java

@@ -3,6 +3,7 @@ package com.alibaba.testable.agent;
 import com.alibaba.testable.agent.transformer.TestableClassTransformer;
 import com.alibaba.testable.agent.util.GlobalConfig;
 import com.alibaba.testable.core.model.MockScope;
+import com.alibaba.testable.core.util.LogUtil;
 import com.alibaba.ttl.threadpool.agent.TtlAgent;
 
 import java.lang.instrument.Instrumentation;
@@ -23,6 +24,7 @@ public class PreMain {
     private static boolean enhanceThreadLocal = false;
 
     public static void premain(String agentArgs, Instrumentation inst) {
+        GlobalConfig.setupLogRootPath();
         parseArgs(agentArgs);
         if (enhanceThreadLocal) {
             // add transmittable thread local transformer
@@ -30,6 +32,7 @@ public class PreMain {
         }
         // add testable mock transformer
         inst.addTransformer(new TestableClassTransformer());
+        cleanup();
     }
 
     private static void parseArgs(String args) {
@@ -60,4 +63,13 @@ public class PreMain {
         }
     }
 
+    private static void cleanup() {
+        Runtime.getRuntime().addShutdownHook(new Thread() {
+            @Override
+            public void run() {
+                LogUtil.cleanup();
+            }
+        });
+    }
+
 }

testable-agent/src/main/java/com/alibaba/testable/agent/util/BytecodeUtil.java

@@ -211,7 +211,7 @@ public class BytecodeUtil {
             return;
         }
         try {
-            String dumpFile = StringUtil.joinPath(dumpPath,
+            String dumpFile = PathUtil.join(dumpPath,
                 className.replace(SLASH, DOT).replace(DOLLAR, UNDERLINE) + ".class");
             LogUtil.verbose("Dump class: " + dumpFile);
             FileOutputStream stream = new FileOutputStream(dumpFile);

testable-agent/src/main/java/com/alibaba/testable/agent/util/GlobalConfig.java

@@ -14,6 +14,7 @@ public class GlobalConfig {
     private static final String MUTE = "mute";
     private static final String DEBUG = "debug";
     private static final String VERBOSE = "verbose";
+    private static final String USER_DIR = "user.dir";
 
     private static String dumpPath = null;
     private static String pkgPrefix = null;
@@ -56,4 +57,9 @@ public class GlobalConfig {
     public static void setDefaultMockScope(MockScope scope) {
         defaultMockScope = scope;
     }
+
+    public static void setupLogRootPath() {
+        LogUtil.setGlobalLogPath(
+            PathUtil.getFirstLevelFolder(System.getProperty(USER_DIR), Object.class.getResource("/").getPath()));
+    }
 }

testable-agent/src/main/java/com/alibaba/testable/agent/util/PathUtil.java

@@ -0,0 +1,31 @@
+package com.alibaba.testable.agent.util;
+
+import java.io.File;
+
+public class PathUtil {
+
+    /**
+     * Join a path text and a file name to full file path
+     * @param folder path text
+     * @param file file name
+     * @return joined full file path
+     */
+    public static String join(String folder, String file) {
+        return (folder.endsWith(File.separator) ? folder : (folder + File.separator)) + file;
+    }
+
+    /**
+     * Get the absolute path of the first sub-folder from root folder to target path
+     * @param rootFolder specify root folder path
+     * @param targetPath any sub path inside root folder
+     * @return first sub-folder path
+     */
+    public static String getFirstLevelFolder(String rootFolder, String targetPath) {
+        if (!targetPath.startsWith(rootFolder) || targetPath.length() <= rootFolder.length() + 1) {
+            return "";
+        }
+        char separator = targetPath.charAt(rootFolder.length());
+        int pos = targetPath.indexOf(separator, rootFolder.length() + 1);
+        return pos > 0 ? targetPath.substring(0, pos) : "";
+    }
+}

testable-agent/src/main/java/com/alibaba/testable/agent/util/StringUtil.java

@@ -1,7 +1,5 @@
 package com.alibaba.testable.agent.util;
 
-import java.io.File;
-
 /**
  * @author flin
  */
@@ -21,14 +19,4 @@ public class StringUtil {
         return sb.toString();
     }
 
-    /**
-     * join a path text and a file name to full file path
-     * @param folder path text
-     * @param file file name
-     * @return joined full file path
-     */
-    public static String joinPath(String folder, String file) {
-        return (folder.endsWith(File.separator) ? folder : (folder + File.separator)) + file;
-    }
-
 }

testable-agent/src/test/java/com/alibaba/testable/agent/util/PathUtilTest.java

@@ -0,0 +1,17 @@
+package com.alibaba.testable.agent.util;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class PathUtilTest {
+
+    @Test
+    void should_get_sub_folder() {
+        assertEquals("/ab/cd", PathUtil.getFirstLevelFolder("/ab", "/ab/cd/ef/gh"));
+        assertEquals("c:\\ab\\cd", PathUtil.getFirstLevelFolder("c:\\ab", "c:\\ab\\cd\\ef\\gh"));
+        assertEquals("", PathUtil.getFirstLevelFolder("/ab", "/ab"));
+        assertEquals("", PathUtil.getFirstLevelFolder("/ab/cd", "/ab"));
+    }
+
+}

testable-core/src/main/java/com/alibaba/testable/core/util/LogUtil.java

@@ -2,34 +2,55 @@ package com.alibaba.testable.core.util;
 
 import com.alibaba.testable.core.model.LogLevel;
 
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Date;
+
 /**
  * @author flin
  */
 public class LogUtil {
 
+    private static final String TESTABLE_AGENT_LOG = "testable-agent.log";
+
     private static LogLevel defaultLogLevel = LogLevel.DEFAULT;
     private static LogLevel currentLogLevel = LogLevel.DEFAULT;
+    private static FileOutputStream logFileStream = null;
 
     public static void verbose(String msg, Object... args) {
         if (isVerboseEnabled()) {
-            System.out.println(String.format("[VERBOSE] " + msg, args));
+            String text = String.format(msg + "\n", args);
+            System.out.print("[VERBOSE] ");
+            System.out.print(text);
+            write("[TIP] ");
+            write(text);
         }
     }
 
     public static void diagnose(String msg, Object... args) {
+        String text = String.format(msg + "\n", args);
         if (currentLogLevel.level >= LogLevel.ENABLE.level) {
-            System.out.println(String.format("[DIAGNOSE] " + msg, args));
+            System.out.print("[DIAGNOSE] ");
+            System.out.print(text);
         }
+        write("[INFO] ");
+        write(text);
     }
 
     public static void warn(String msg, Object... args) {
+        String text = String.format("[WARN] " + msg + "\n", args);
         if (currentLogLevel.level >= LogLevel.DEFAULT.level) {
-            System.err.println(String.format("[WARN] " + msg, args));
+            System.err.print(text);
         }
+        write(text);
     }
 
     public static void error(String msg, Object... args) {
-        System.err.println(String.format("[ERROR] " + msg, args));
+        String text = String.format("[ERROR] " + msg + "\n", args);
+        System.err.print(text);
+        write(text);
     }
 
     /**
@@ -52,4 +73,38 @@ public class LogUtil {
         currentLogLevel = defaultLogLevel;
     }
 
+    public static void setGlobalLogPath(String logFolderPath) {
+        if (logFolderPath.isEmpty()) {
+            return;
+        }
+        String logFilePath = logFolderPath + File.separator + TESTABLE_AGENT_LOG;
+        try {
+            logFileStream = new FileOutputStream(logFilePath);
+            diagnose("Start at %s", new Date().toString());
+        } catch (FileNotFoundException e) {
+            warn("Failed to create log file %s", logFilePath);
+        }
+    }
+
+    public static void cleanup() {
+        try {
+            if (logFileStream != null) {
+                diagnose("Completed at %s", new Date().toString());
+                logFileStream.flush();
+                logFileStream.close();
+            }
+        } catch (IOException e) {
+            warn("Log file is not closed properly");
+        }
+    }
+
+    private static void write(String text) {
+        try {
+            if (logFileStream != null) {
+                logFileStream.write(text.getBytes());
+            }
+        } catch (IOException e) {
+            // ignore
+        }
+    }
 }