#177 followup - add test, format and tidy internals

Also exclude include fields in fromJson() that are not
used due to being read-only json properties

Author: rbygrave

blackbox-test/src/main/java/org/example/customer/naming/WithName.java

@@ -11,4 +11,11 @@ public record WithName(
   String simplePlus,
   int myOneRed) {
 
+  /**
+   * A read-only JSON property without an underlying field.
+   */
+  @Json.Property("derived")
+  public int calculated() {
+    return myOneRed * 2;
+  }
 }

blackbox-test/src/test/java/org/example/customer/naming/WithNameTest.java

@@ -17,7 +17,7 @@ void toFrom()  {
     WithName bean = new WithName("sim", "simPlus", 42);
 
     String asJson = jsonType.toJson(bean);
-    assertThat(asJson).isEqualTo("{\"Some Thing Odd\":\"sim\",\"simple-plus\":\"simPlus\",\"my-one-red\":42}");
+    assertThat(asJson).isEqualTo("{\"Some Thing Odd\":\"sim\",\"simple-plus\":\"simPlus\",\"my-one-red\":42,\"derived\":84}");
 
     WithName fromJson = jsonType.fromJson(asJson);
     assertEquals(fromJson, bean);

jsonb-generator/src/main/java/io/avaje/jsonb/generator/ClassReader.java

@@ -424,10 +424,12 @@ private void writeFromJsonImplementation(Append writer, String varName) {
     } else {
       writer.append("    // variables to read json values into, constructor params don't need _set$ flags").eol();
       for (final FieldReader allField : allFields) {
-        if (isRecord) {
-          allField.writeFromJsonVariablesRecord(writer);
-        } else if (allField.includeFromJson()) {
-          allField.writeFromJsonVariables(writer);
+        if (allField.includeFromJson()) {
+          if (isRecord) {
+            allField.writeFromJsonVariablesRecord(writer);
+          } else {
+            allField.writeFromJsonVariables(writer);
+          }
         }
       }
     }

jsonb-generator/src/main/java/io/avaje/jsonb/generator/FieldReader.java

@@ -32,16 +32,13 @@ final class FieldReader {
 
     final var fieldName = element.getSimpleName().toString();
     final var publicField = !isMethod && element.getModifiers().contains(Modifier.PUBLIC);
+    final var type = isMethod ? ((ExecutableElement) element).getReturnType() : element.asType();
 
-    var type = isMethod ? ((ExecutableElement) element).getReturnType() : element.asType();
-
-    this.property =
-        new FieldProperty(type, raw, unmapped, genericTypeParams, publicField, fieldName);
-    this.propertyName =
-        PropertyPrism.getOptionalOn(element)
-            .map(PropertyPrism::value)
-            .map(Util::escapeQuotes)
-            .orElse(namingConvention.from(fieldName));
+    this.property = new FieldProperty(type, raw, unmapped, genericTypeParams, publicField, fieldName);
+    this.propertyName = PropertyPrism.getOptionalOn(element)
+      .map(PropertyPrism::value)
+      .map(Util::escapeQuotes)
+      .orElse(namingConvention.from(fieldName));
 
     this.aliases = initAliases(element);
   }

jsonb-generator/src/main/java/io/avaje/jsonb/generator/TypeReader.java

@@ -58,10 +58,9 @@ final class TypeReader {
     if (mixInType == null) {
       this.mixInFields = new HashMap<>();
     } else {
-      this.mixInFields =
-        mixInType.getEnclosedElements().stream()
-          .filter(e -> e.getKind() == ElementKind.FIELD)
-          .collect(Collectors.toMap(e -> e.getSimpleName().toString(), e -> e));
+      this.mixInFields = mixInType.getEnclosedElements().stream()
+        .filter(e -> e.getKind() == ElementKind.FIELD)
+        .collect(Collectors.toMap(e -> e.getSimpleName().toString(), e -> e));
     }
     this.namingConvention = namingConvention;
     this.hasJsonAnnotation = JsonPrism.isPresent(baseType) || importedJson(baseType).isPresent();
@@ -129,11 +128,18 @@ private void readField(Element element, List<FieldReader> localFields) {
       optional = true;
     }
     if (includeField(element)) {
-      final var frequency = frequencyMap.compute(element.getSimpleName().toString(), (k, v) -> v == null ? 0 : v + 1);
+      final var frequency = frequency(element.getSimpleName().toString());
       localFields.add(new FieldReader(element, namingConvention, currentSubType, genericTypeParams, frequency));
     }
   }
 
+  /**
+   * Compute and return the frequency of the key / json property name.
+   */
+  private Integer frequency(String key) {
+    return frequencyMap.compute(key, (k, v) -> v == null ? 0 : v + 1);
+  }
+
   private boolean includeField(Element element) {
     if (extendsThrowable) {
       return !element.getModifiers().contains(Modifier.TRANSIENT)
@@ -186,24 +192,19 @@ private void readMethod(Element element, TypeElement type, List<FieldReader> loc
         }
       }
     }
-    // for reading methods
-    PropertyPrism.getOptionalOn(methodElement)
-        .ifPresent(
-            p -> {
-              if (!methodElement.getParameters().isEmpty()) {
-                logError("Json.Property can only be placed on Getter Methods", methodElement);
-                return;
-              }
-
-              final var frequency =
-                  frequencyMap.compute(p.value(), (k, v) -> v == null ? 0 : v + 1);
-
-              final var reader =
-                  new FieldReader(
-                      element, namingConvention, currentSubType, genericTypeParams, frequency);
-              localFields.add(reader);
-              reader.getterMethod(new MethodReader(methodElement, type));
-            });
+    // for getter/accessor methods only, not setters
+    PropertyPrism.getOptionalOn(methodElement).ifPresent(propertyPrism -> {
+      if (!methodElement.getParameters().isEmpty()) {
+        logError("Json.Property can only be placed on Getter Methods, but on %s", methodElement);
+        return;
+      }
+
+      // getter property as simulated read-only field with getter method
+      final var frequency = frequency(propertyPrism.value());
+      final var reader = new FieldReader(element, namingConvention, currentSubType, genericTypeParams, frequency);
+      reader.getterMethod(new MethodReader(methodElement, type));
+      localFields.add(reader);
+    });
   }
 
   private boolean checkMethod2(ExecutableElement methodElement) {

jsonb/src/main/java/io/avaje/jsonb/Json.java

@@ -138,7 +138,7 @@
   }
 
   /**
-   * @deprecated - migrate to {@link Json.Alias}.
+   * Deprecated - migrate to {@link Json.Alias}.
    */
   @Deprecated
   @Retention(CLASS)