Delegate assertTrue/assertFalse/fail to AssertJ

src/main/java/org/testng/Assert.java

@@ -59,9 +59,8 @@ protected Assert() {
    * @param message the assertion error message
    */
   public static void assertTrue(boolean condition, String message) {
-    if (!condition) {
-      failNotEquals(condition, Boolean.TRUE, message);
-    }
+    // Delegated to AssertJ (behaviour-identical, only the failure message differs).
+    assertThat(condition).as(message).isTrue();
   }
 
   /**
@@ -81,9 +80,8 @@ public static void assertTrue(boolean condition) {
    * @param message the assertion error message
    */
   public static void assertFalse(boolean condition, String message) {
-    if (condition) {
-      failNotEquals(condition, Boolean.FALSE, message); // TESTNG-81
-    }
+    // Delegated to AssertJ (behaviour-identical, only the failure message differs).
+    assertThat(condition).as(message).isFalse();
   }
 
   /**
@@ -102,10 +100,9 @@ public static void assertFalse(boolean condition) {
    * @param realCause the original exception
    */
   public static void fail(String message, Throwable realCause) {
-    AssertionError ae = new AssertionError(message);
-    ae.initCause(realCause);
-
-    throw ae;
+    // Delegated to AssertJ (behaviour-identical: throws an AssertionError with the given message
+    // and cause).
+    org.assertj.core.api.Assertions.fail(message, realCause);
   }
 
   /**
@@ -114,7 +111,8 @@ public static void fail(String message, Throwable realCause) {
    * @param message the assertion error message
    */
   public static void fail(String message) {
-    throw new AssertionError(message);
+    // Delegated to AssertJ (behaviour-identical: throws an AssertionError with the given message).
+    org.assertj.core.api.Assertions.fail(message);
   }
 
   /** Fails a test with no message. */

src/test/java/org/testng/AssertTest.java

@@ -437,15 +437,15 @@ public void testAssertEqualsNoOrderNotDeep() {
   @Test(
       description = "GITHUB-2080",
       expectedExceptions = AssertionError.class,
-      expectedExceptionsMessageRegExp = "test expected \\[true\\] but found \\[false\\]")
+      expectedExceptionsMessageRegExp = "(?s)\\[test\\] .*Expecting value to be true but was false")
   public void testAssertTrueMessage() {
     Assert.assertTrue(false, "test");
   }
 
   @Test(
       description = "GITHUB-2080",
       expectedExceptions = AssertionError.class,
-      expectedExceptionsMessageRegExp = "test expected \\[false\\] but found \\[true\\]")
+      expectedExceptionsMessageRegExp = "(?s)\\[test\\] .*Expecting value to be false but was true")
   public void testAssertFalseMessage() {
     Assert.assertFalse(true, "test");
   }

src/test/java/test/assertion/AssertionTest.java

@@ -36,7 +36,9 @@ public void test2() {
             "onAfterAssert");
   }
 
-  @Test(expectedExceptions = AssertionError.class, expectedExceptionsMessageRegExp = "Raw test .*")
+  @Test(
+      expectedExceptions = AssertionError.class,
+      expectedExceptionsMessageRegExp = "(?s)\\[Raw test\\] .*")
   public void test2_fails() {
     try {
       rawAssertion.assertTrue(true);

src/test/java/test/assertion/SoftAssertTest.java

@@ -63,10 +63,11 @@ public void testAssertAllCount() {
       sa.assertAll();
       Assert.fail("Exception expected");
     } catch (AssertionError e) {
-      String[] lines = e.getMessage().split("\r?\n");
-      Assert.assertEquals(lines.length, 2);
-      lines[1] = lines[1].replaceFirst(message, "");
-      Assert.assertFalse(lines[1].contains(message));
+      // Exactly one assertion failed, so the user message is reported exactly once. (Line counting
+      // is avoided here because the delegated AssertJ failure messages span multiple lines.)
+      String report = e.getMessage();
+      Assert.assertTrue(report.contains(message), report);
+      Assert.assertEquals(report.indexOf(message), report.lastIndexOf(message), report);
     }
   }