Fixed a bug in AssertThatBinaryExpression inspection for assertThat(null != expression) and related that would not correctly invert the condition on transformation.

src/main/java/de/platon42/intellij/plugins/cajon/inspections/AssertThatBinaryExpressionInspection.kt

@@ -38,7 +38,13 @@ class AssertThatBinaryExpressionInspection : AbstractAssertJInspection() {
 
                 if (isLeftNull && isRightNull) return
                 if (isLeftNull || isRightNull) {
-                    val replacementMethod = expectedResult.map(MethodNames.IS_NULL, MethodNames.IS_NOT_NULL)
+                    val expectedResultOnOp =
+                        when (binaryExpression.operationTokenType) {
+                            JavaTokenType.EQEQ -> expectedResult
+                            JavaTokenType.NE -> !expectedResult
+                            else -> return
+                        }
+                    val replacementMethod = expectedResultOnOp.map(MethodNames.IS_NULL, MethodNames.IS_NOT_NULL)
                     registerSplitMethod(holder, expectedCallExpression, replacementMethod) { desc, method ->
                         SplitBinaryExpressionMethodCallQuickFix(desc, method, pickRightOperand = isLeftNull, noExpectedExpression = true)
                     }

src/test/java/de/platon42/intellij/plugins/cajon/inspections/AssertThatBinaryExpressionInspectionTest.kt

@@ -13,7 +13,7 @@ internal class AssertThatBinaryExpressionInspectionTest : AbstractCajonTest() {
     internal fun assertThat_of_binary_expression_can_be_moved_out(@MyFixture myFixture: JavaCodeInsightTestFixture) {
         myFixture.enableInspections(AssertThatBinaryExpressionInspection::class.java)
         myFixture.configureByFile("BinaryExpressionBefore.java")
-        executeQuickFixes(myFixture, Regex.fromLiteral("Split binary expression out of assertThat()"), 149)
+        executeQuickFixes(myFixture, Regex.fromLiteral("Split binary expression out of assertThat()"), 161)
         myFixture.checkResultByFile("BinaryExpressionAfter.java")
     }
 }

src/test/resources/inspections/BinaryExpression/BinaryExpressionAfter.java

@@ -189,6 +189,20 @@ public class BinaryExpression {
         assertThat(stringAct).isNotNull();
         assertThat(stringAct).isNotNull();
 
+        assertThat(stringAct).as("doh!").isNotNull();
+        assertThat(stringAct).isNotNull();
+        assertThat(stringAct).isNotNull();
+        assertThat(stringAct).isNull();
+        assertThat(stringAct).isNull();
+        assertThat(stringAct).isNull();
+
+        assertThat(stringAct).as("doh!").isNotNull();
+        assertThat(stringAct).isNotNull();
+        assertThat(stringAct).isNotNull();
+        assertThat(stringAct).isNull();
+        assertThat(stringAct).isNull();
+        assertThat(stringAct).isNull();
+
         assertThat(null == null).isTrue();
         assertThat(!false).isTrue();
 

src/test/resources/inspections/BinaryExpression/BinaryExpressionBefore.java

@@ -189,6 +189,20 @@ public class BinaryExpression {
         assertThat(null == stringAct).isEqualTo(false);
         assertThat(null == stringAct).isNotEqualTo(true);
 
+        assertThat(stringAct != null).as("doh!").isTrue();
+        assertThat(stringAct != null).isEqualTo(true);
+        assertThat(stringAct != null).isNotEqualTo(false);
+        assertThat(stringAct != null).isFalse();
+        assertThat(stringAct != null).isEqualTo(false);
+        assertThat(stringAct != null).isNotEqualTo(true);
+
+        assertThat(null != stringAct).as("doh!").isTrue();
+        assertThat(null != stringAct).isEqualTo(true);
+        assertThat(null != stringAct).isNotEqualTo(false);
+        assertThat(null != stringAct).isFalse();
+        assertThat(null != stringAct).isEqualTo(false);
+        assertThat(null != stringAct).isNotEqualTo(true);
+
         assertThat(null == null).isTrue();
         assertThat(!false).isTrue();