fix: improve error-message for unknown nested field

When a nested field is customized (e.g. `.with("parent.xxx", 42)`), but the field `xxx` doesn't exist in `parent`, a proper exception is thrown, but then misinterpreted as a failure to construct the object via reflection, then retried using the constructor which then fails ultimately with a misleading message. Instead, we introduced a specialized exception for customization-validation that will bubble up with the proper error-message without being misinterpreted.

Author: Nylle

src/main/java/com/github/nylle/javafixture/CustomizationException.java

@@ -0,0 +1,7 @@
+package com.github.nylle.javafixture;
+
+public class CustomizationException extends RuntimeException {
+ public CustomizationException(String message) {
+ super(message);
+ }
+}

src/main/java/com/github/nylle/javafixture/InstanceFactory.java

@@ -253,7 +253,7 @@ private static <T> List<Constructor<T>> findValidConstructors(SpecimenType<T> ty
  var result = candidates.stream().filter(x -> x.getValue().isEmpty()).map(x -> x.getKey()).collect(toList());
 
  if (result.isEmpty()) {
- throw new SpecimenException(Stream.concat(
+ throw new CustomizationException(Stream.concat(
  Stream.of("Cannot customize fields because no suitable constructor was found. Candidates are:"),
  candidates.stream().map(x -> String.format(" %s(%s) (Missing fields: %s)",
  x.getKey().getName(),

src/main/java/com/github/nylle/javafixture/Reflector.java

@@ -34,7 +34,7 @@ public Reflector<T> validateCustomization(CustomizationContext customizationCont
  .findFirst();
 
  if (missingDeclaredField.isPresent()) {
- throw new SpecimenException(format("Cannot customize field '%s': Field not found in class '%s'.", missingDeclaredField.get(), type.getName()));
+ throw new CustomizationException(format("Cannot customize field '%s': Field not found in class '%s'.", missingDeclaredField.get(), type.getName()));
  }
 
  var duplicateField = getDeclaredFields(type.asClass())
@@ -48,7 +48,7 @@ public Reflector<T> validateCustomization(CustomizationContext customizationCont
  .findFirst();
 
  if (duplicateField.isPresent()) {
- throw new SpecimenException(format("Cannot customize field '%s'. Duplicate field names found: %n%s",
+ throw new CustomizationException(format("Cannot customize field '%s'. Duplicate field names found: %n%s",
  duplicateField.get().getKey(),
  duplicateField.get().getValue().stream().map(x -> x.toString()).collect(joining("\n"))));
  }

src/test/java/com/github/nylle/javafixture/InstanceFactoryTest.java

@@ -71,7 +71,7 @@ void throwsExceptionForInvalidCustomization() {
  "arg1.nested", new Object(),
  "missingCustomization", new Object()), false);
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.construct(type, context))
  .withMessageContaining(format("Cannot customize fields because no suitable constructor was found. Candidates are:%n"))
  .withMessageContaining(format(" com.github.nylle.javafixture.testobjects.withconstructor.TestObjectWithTwoConstructors(arg0,arg1) (Missing fields: [missingCustomization, missingExclusion])%n"))

src/test/java/com/github/nylle/javafixture/ReflectorTest.java

@@ -52,7 +52,7 @@ void invalidCustomization() {
 
  var invalidCustomisation = new CustomizationContext(List.of(), Map.of("nonExistingField.subField", "foo"), false);
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.validateCustomization(invalidCustomisation))
  .withMessage("Cannot customize field 'nonExistingField': Field not found in class 'com.github.nylle.javafixture.testobjects.inheritance.GenericChild<java.lang.String>'.")
  .withNoCause();
@@ -68,7 +68,7 @@ void customizingDuplicateFields() {
 
  var invalidCustomisation = new CustomizationContext(List.of(), customization, false);
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.validateCustomization(invalidCustomisation))
  .withMessageContaining("Cannot customize field 'fieldIn2Classes'. Duplicate field names found:")
  .withMessageContaining("private java.lang.Double com.github.nylle.javafixture.testobjects.inheritance.GenericParent.fieldIn2Classes")
@@ -86,7 +86,7 @@ void omittingDuplicateFields() {
 
  var invalidCustomisation = new CustomizationContext(omitting, Map.of(), false);
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.validateCustomization(invalidCustomisation))
  .withMessageContaining("Cannot customize field 'fieldIn2Classes'. Duplicate field names found:")
  .withMessageContaining("private java.lang.Double com.github.nylle.javafixture.testobjects.inheritance.GenericParent.fieldIn2Classes")

src/test/java/com/github/nylle/javafixture/specimen/GenericSpecimenTest.java

@@ -3,7 +3,7 @@
 import com.github.nylle.javafixture.Configuration;
 import com.github.nylle.javafixture.Context;
 import com.github.nylle.javafixture.CustomizationContext;
-import com.github.nylle.javafixture.SpecimenException;
+import com.github.nylle.javafixture.CustomizationException;
 import com.github.nylle.javafixture.SpecimenFactory;
 import com.github.nylle.javafixture.SpecimenType;
 import com.github.nylle.javafixture.annotations.testcases.TestCase;
@@ -265,7 +265,7 @@ void firstFieldPerNameIsCustomized() {
  "fieldIn3Classes", "foo",
  "fieldIn2Classes", 100.0);
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.create(new CustomizationContext(List.of(), customization, false), new Annotation[0]));
  }
 
@@ -278,7 +278,7 @@ void firstFieldPerNameIsOmitted() {
  "fieldIn3Classes",
  "fieldIn2Classes");
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.create(new CustomizationContext(omitting, Map.of(), false), new Annotation[0]));
  }
  }

src/test/java/com/github/nylle/javafixture/specimen/ObjectSpecimenTest.java

@@ -3,7 +3,7 @@
 import com.github.nylle.javafixture.Configuration;
 import com.github.nylle.javafixture.Context;
 import com.github.nylle.javafixture.CustomizationContext;
-import com.github.nylle.javafixture.SpecimenException;
+import com.github.nylle.javafixture.CustomizationException;
 import com.github.nylle.javafixture.SpecimenFactory;
 import com.github.nylle.javafixture.SpecimenType;
 import com.github.nylle.javafixture.annotations.testcases.TestCase;
@@ -132,7 +132,18 @@ void cannotSetNonExistingField() {
 
  var customizationContext = new CustomizationContext(List.of(), Map.of("nonExistingField", "foo"), false);
 
- assertThatExceptionOfType(Exception.class)
+ assertThatExceptionOfType(CustomizationException.class)
+ .isThrownBy(() -> sut.create(customizationContext, new Annotation[0]))
+ .withMessage("Cannot customize field 'nonExistingField': Field not found in class 'com.github.nylle.javafixture.testobjects.TestObject'.")
+ .withNoCause();
+ }
+
+ @Test
+ void cannotSetNonExistingNestedField() {
+ var sut = new ObjectSpecimen<WithTestObject>(SpecimenType.fromClass(WithTestObject.class), context, specimenFactory);
+ var customizationContext = new CustomizationContext(List.of(), Map.of("testObject.nonExistingField", "42"), false);
+
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.create(customizationContext, new Annotation[0]))
  .withMessage("Cannot customize field 'nonExistingField': Field not found in class 'com.github.nylle.javafixture.testobjects.TestObject'.")
  .withNoCause();
@@ -144,7 +155,18 @@ void cannotOmitNonExistingField() {
 
  var customizationContext = new CustomizationContext(List.of("nonExistingField"), Map.of(), false);
 
- assertThatExceptionOfType(Exception.class)
+ assertThatExceptionOfType(CustomizationException.class)
+ .isThrownBy(() -> sut.create(customizationContext, new Annotation[0]))
+ .withMessage("Cannot customize field 'nonExistingField': Field not found in class 'com.github.nylle.javafixture.testobjects.TestObject'.")
+ .withNoCause();
+ }
+
+ @Test
+ void cannotOmitNonExistingNestedField() {
+ var sut = new ObjectSpecimen<WithTestObject>(SpecimenType.fromClass(WithTestObject.class), context, specimenFactory);
+ var customizationContext = new CustomizationContext(List.of("testObject.nonExistingField"), Map.of(), false);
+
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.create(customizationContext, new Annotation[0]))
  .withMessage("Cannot customize field 'nonExistingField': Field not found in class 'com.github.nylle.javafixture.testobjects.TestObject'.")
  .withNoCause();
@@ -225,7 +247,7 @@ void firstFieldPerNameIsCustomized() {
  "fieldIn3Classes", "foo",
  "fieldIn2Classes", 100.0);
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.create(new CustomizationContext(List.of(), customization, false), new Annotation[0]));
  }
 
@@ -238,7 +260,7 @@ void firstFieldPerNameIsOmitted() {
  "fieldIn3Classes",
  "fieldIn2Classes");
 
- assertThatExceptionOfType(SpecimenException.class)
+ assertThatExceptionOfType(CustomizationException.class)
  .isThrownBy(() -> sut.create(new CustomizationContext(omitting, Map.of(), false), new Annotation[0]));
  }
  }