SONARJAVA-5797 Fix FP in S2698 on fail and assertEquals with a message (#5332)

Author: tomasz-tylenda-sonarsource

its/autoscan/src/test/resources/autoscan/diffs/diff_S3415.json

@@ -1,6 +1,6 @@
 {
   "ruleKey": "S3415",
   "hasTruePositives": false,
-  "falseNegatives": 280,
+  "falseNegatives": 286,
   "falsePositives": 0
-}
+}

java-checks-test-sources/default/src/test/java/checks/tests/AssertionsWithoutMessageCheckSample.java

@@ -17,6 +17,21 @@ void foo() {
     org.testng.Assert.assertTrue(true, "msg"); // Compliant
     org.testng.Assert.assertTrue(true); // Noncompliant
     org.testng.AssertJUnit.assertTrue(true); // Noncompliant
+
+    org.testng.Assert.fail(); // Noncompliant
+    org.testng.Assert.fail("msg"); // Compliant
+
+    org.testng.Assert.assertEquals(2, 3); // Noncompliant
+    org.testng.Assert.assertEquals(2, 3, "two is not equal three"); // Compliant
+
+    org.testng.Assert.assertEquals(2.0, 3.1, 0.01); // Noncompliant
+    org.testng.Assert.assertEquals(2.1, 3.2, 0.01, "diff more than delta"); // Compliant
+
+    org.testng.Assert.assertEquals("abc", "abc"); // Noncompliant
+    org.testng.Assert.assertEquals("abc", "abc", "msg for strings"); // Compliant
+
+    org.testng.Assert.assertThrows(() -> {}); // Compliant
+
     org.assertj.core.api.Assertions.assertThat("").usingComparator(null).as("a").isEqualTo(222); // Compliant
     org.junit.Assert.assertTrue(true); // Noncompliant {{Add a message to this assertion.}}
 //                   ^^^^^^^^^^

java-checks/src/main/java/org/sonar/java/checks/tests/AssertionsWithoutMessageCheck.java

@@ -115,9 +115,26 @@ protected void onMethodInvocationFound(MethodInvocationTree mit) {
    * and it is the first of the last argument (depending on the assertion library).
    */
   private static boolean hasMessageArg(MethodInvocationTree mit, Type type) {
-    int expectedMessageArgIndex = (type.is("org.testng.Assert") || type.is("org.testng.AssertJUnit")) ? 1 : 0;
     List<ExpressionTree> args = mit.arguments();
-    return expectedMessageArgIndex < args.size() && isString(args.get(expectedMessageArgIndex));
+
+    // `fail` needs one argument. Assume it is a string.
+    if ("fail".equals(mit.methodSymbol().name())) {
+      return !args.isEmpty();
+    }
+
+    // In TestNG, the message is the last argument.
+    if (type.is("org.testng.Assert") || type.is("org.testng.AssertJUnit")) {
+      // Depending on the version of TestNG, assertThrows may or may not have the variant with a message.
+      // For simplicity, do not raise.
+      if ("assertThrows".equals(mit.methodSymbol().name())) {
+        return true;
+      }
+      int expectedMessageArgIndex = args.size() - 1;
+      return expectedMessageArgIndex > 0 && isString(args.get(expectedMessageArgIndex));
+    }
+
+    // In JUnit and others, the message is the first argument.
+    return !args.isEmpty() && isString(args.get(0));
   }
 
   private void checkFestLikeAssertion(MethodInvocationTree mit, Symbol symbol, IdentifierTree reportLocation) {