Rewrites instantiation

CHANGELOG.md

@@ -13,6 +13,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- #withPrefabValuesForField method, where you can assign prefab values to a field instead of to a class. The values will then be used for that field only. ([Issue 747](https://github.com/jqno/equalsverifier/issues/747))
+
+### Changed
+
+- The internal instantiation logic has been heavily refactored.
+
+### Deprecated
+
+- `Warning.ZERO_FIELDS`: the use case for this Warning is better handled by the new `#withPrefabValuesForField` method.
+
 ## [3.16.2] - 2024-08-23
 
 ### Changed

equalsverifier-16/src/test/java/nl/jqno/equalsverifier/integration/extended_contract/PrefabValuesForFieldInRecordTest.java

@@ -0,0 +1,73 @@
+package nl.jqno.equalsverifier.integration.extended_contract;
+
+import nl.jqno.equalsverifier.EqualsVerifier;
+import nl.jqno.equalsverifier.internal.testhelpers.ExpectedException;
+import org.junit.jupiter.api.Test;
+
+public class PrefabValuesForFieldInRecordTest {
+
+    @Test
+    public void fail_whenRecordHasSinglePrecondition() {
+        ExpectedException
+            .when(() -> EqualsVerifier.forClass(SinglePrecondition.class).verify())
+            .assertFailure()
+            .assertMessageContains("Record:", "failed to run constructor", "[1]");
+    }
+
+    @Test
+    public void succeed_whenRecordHasSinglePrecondition_givenPrefabValuesForField() {
+        EqualsVerifier
+            .forClass(SinglePrecondition.class)
+            .withPrefabValuesForField("i", 111, 142)
+            .verify();
+    }
+
+    @Test
+    public void fail_whenRecordHasDualPrecondition() {
+        ExpectedException
+            .when(() -> EqualsVerifier.forClass(DualPrecondition.class).verify())
+            .assertFailure()
+            .assertMessageContains("Record:", "failed to run constructor", "[1, 1]");
+    }
+
+    @Test
+    public void fail_whenRecordHasDualPrecondition_givenPrefabValuesForOnlyOneField() {
+        ExpectedException
+            .when(() ->
+                EqualsVerifier
+                    .forClass(DualPrecondition.class)
+                    .withPrefabValuesForField("x", 111, 142)
+                    .verify()
+            )
+            .assertFailure()
+            .assertMessageContains("Record:", "failed to run constructor", "[111, 1]");
+    }
+
+    @Test
+    public void succeed_whenRecordHasDualPrecondition_givenPrefabValueForBothFields() {
+        EqualsVerifier
+            .forClass(DualPrecondition.class)
+            .withPrefabValuesForField("x", 111, 142)
+            .withPrefabValuesForField("y", 505, 555)
+            .verify();
+    }
+
+    record SinglePrecondition(int i) {
+        public SinglePrecondition {
+            if (i < 100 || i > 200) {
+                throw new IllegalArgumentException("i must be between 100 and 200! But was " + i);
+            }
+        }
+    }
+
+    record DualPrecondition(int x, int y) {
+        public DualPrecondition {
+            if (x < 100 || x > 200) {
+                throw new IllegalArgumentException("x must be between 100 and 200! But was " + x);
+            }
+            if (y < 500 || y > 600) {
+                throw new IllegalArgumentException("y must be between 500 and 600! But was " + y);
+            }
+        }
+    }
+}

equalsverifier-16/src/test/java/nl/jqno/equalsverifier/integration/extended_contract/RecordsTest.java

@@ -51,15 +51,6 @@ public void fail_whenConstructorChecksValue() {
             .assertMessageContains("Record:", "failed to run constructor", "prefab values");
     }
 
-    @Test
-    public void succeed_whenConstructorChecksValue_givenPrefabValues() {
-        EqualsVerifier
-            .forClass(ValueCheckingRecord.class)
-            .withPrefabValues(int.class, 10, 11)
-            .suppress(Warning.ZERO_FIELDS)
-            .verify();
-    }
-
     @Test
     public void fail_whenRecordInvariantIsViolated_givenIntFieldIsModifiedInConstructor() {
         ExpectedException

equalsverifier-16/src/test/java/nl/jqno/equalsverifier/internal/reflection/ClassProbeRecordTest.java

@@ -0,0 +1,16 @@
+package nl.jqno.equalsverifier.internal.reflection;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+public class ClassProbeRecordTest {
+
+    @Test
+    public void isRecord() {
+        var probe = new ClassProbe<>(SimpleRecord.class);
+        assertTrue(probe.isRecord());
+    }
+
+    record SimpleRecord(int i) {}
+}

equalsverifier-16/src/test/java/nl/jqno/equalsverifier/internal/reflection/RecordInstantiatorTest.java

@@ -3,12 +3,13 @@
 import static org.junit.jupiter.api.Assertions.*;
 
 import org.junit.jupiter.api.Test;
+import org.objenesis.ObjenesisStd;
 
 public class RecordInstantiatorTest {
 
     @Test
     public void instantiateRecord() {
-        Instantiator<?> instantiator = Instantiator.of(SimpleRecord.class);
+        Instantiator<?> instantiator = Instantiator.of(SimpleRecord.class, new ObjenesisStd());
         Object simpleRecord = instantiator.instantiate();
         assertEquals(SimpleRecord.class, simpleRecord.getClass());
     }