ENH: Add support for case-insensitive keys on deserialization

blackbox-test/src/main/java/org/example/customer/caseinsensitive/ICaseContact.java

@@ -0,0 +1,8 @@
+package org.example.customer.caseinsensitive;
+
+import io.avaje.jsonb.Json;
+
+@Json(caseInsensitiveKeys = true)
+public record ICaseContact(int id, String firstName, String lastName) {
+
+}

blackbox-test/src/test/java/org/example/customer/caseinsensitive/ICaseContactTest.java

@@ -0,0 +1,26 @@
+package org.example.customer.caseinsensitive;
+
+import io.avaje.jsonb.JsonType;
+import io.avaje.jsonb.Jsonb;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ICaseContactTest {
+
+  Jsonb jsonb = Jsonb.builder().build();
+
+  @Test
+  void toJsonFromJson() {
+    ICaseContact bean = new ICaseContact(42, "first", "last");
+    String asJson = jsonb.toJson(bean);
+    assertThat(asJson).isEqualTo("{\"id\":42,\"firstName\":\"first\",\"lastName\":\"last\"}");
+
+    JsonType<ICaseContact> type = jsonb.type(ICaseContact.class);
+    ICaseContact fromJson = type.fromJson(asJson);
+
+    assertThat(fromJson).isEqualTo(bean);
+    assertThat(type.fromJson("{\"id\":42,\"FIRSTNAME\":\"first\",\"lastname\":\"last\"}")).isEqualTo(bean);
+    assertThat(type.fromJson("{\"id\":42,\"FirstName\":\"first\",\"LastName\":\"last\"}")).isEqualTo(bean);
+  }
+}

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

@@ -23,6 +23,7 @@ class BeanReader {
   private final TypeReader typeReader;
   private final String typeProperty;
   private final boolean nonAccessibleField;
+  private final boolean caseInsensitiveKeys;
   private FieldReader unmappedField;
   private boolean hasRaw;
 
@@ -33,7 +34,7 @@ class BeanReader {
     NamingConventionReader ncReader = new NamingConventionReader(beanType);
     this.namingConvention = ncReader.get();
     this.typeProperty = ncReader.typeProperty();
-
+    this.caseInsensitiveKeys = ncReader.isCaseInsensitiveKeys();
     this.typeReader = new TypeReader(beanType, context, namingConvention);
     typeReader.process();
     this.nonAccessibleField = typeReader.nonAccessibleField();
@@ -49,6 +50,7 @@ public BeanReader(TypeElement beanType, TypeElement mixInElement, ProcessingCont
     final NamingConventionReader ncReader = new NamingConventionReader(beanType);
     this.namingConvention = ncReader.get();
     this.typeProperty = ncReader.typeProperty();
+    this.caseInsensitiveKeys = ncReader.isCaseInsensitiveKeys();
     this.typeReader = new TypeReader(beanType, mixInElement, context, namingConvention);
     typeReader.process();
     this.nonAccessibleField = typeReader.nonAccessibleField();
@@ -354,22 +356,28 @@ private void writeFromJsonSwitch(Append writer, boolean defaultConstructor, Stri
     writer.append("    reader.beginObject();").eol();
     writer.append("    reader.names(names);").eol();
     writer.append("    while (reader.hasNextField()) {").eol();
-    writer.append("      String fieldName = reader.nextField();").eol();
+    if (caseInsensitiveKeys) {
+      writer.append("      final String origFieldName = reader.nextField();").eol();
+      writer.append("      final String fieldName = origFieldName.toLowerCase();").eol();
+    } else {
+      writer.append("      final String fieldName = reader.nextField();").eol();
+    }
     writer.append("      switch (fieldName) {").eol();
     if (hasSubTypes) {
-      writer.append("        case \"%s\": {", typeProperty).eol();
+      writer.append("        case \"%s\": {", typePropertyKey()).eol();
       writer.append("          type = stringJsonAdapter.fromJson(reader); break;").eol();
       writer.append("        }").eol();
     }
     for (FieldReader allField : allFields) {
-      allField.writeFromJsonSwitch(writer, defaultConstructor, varName);
+      allField.writeFromJsonSwitch(writer, defaultConstructor, varName, caseInsensitiveKeys);
     }
     writer.append("        default: {").eol();
+    String unmappedFieldName = caseInsensitiveKeys ? "origFieldName" : "fieldName";
     if (unmappedField != null) {
       writer.append("          Object value = objectJsonAdapter.fromJson(reader);").eol();
-      writer.append("          unmapped.put(fieldName, value);").eol();
+      writer.append("          unmapped.put(%s, value);", unmappedFieldName).eol();
     } else {
-      writer.append("          reader.unmappedField(fieldName);").eol();
+      writer.append("          reader.unmappedField(%s);", unmappedFieldName).eol();
       writer.append("          reader.skipValue();").eol();
     }
     writer.append("        }").eol();
@@ -378,4 +386,8 @@ private void writeFromJsonSwitch(Append writer, boolean defaultConstructor, Stri
     writer.append("    reader.endObject();").eol();
   }
 
+  private String typePropertyKey() {
+    return caseInsensitiveKeys ? typeProperty.toLowerCase() : typeProperty;
+  }
+
 }

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

@@ -300,17 +300,18 @@ private String pad(String value) {
     return sb.toString();
   }
 
-  void writeFromJsonSwitch(Append writer, boolean defaultConstructor, String varName) {
+  void writeFromJsonSwitch(Append writer, boolean defaultConstructor, String varName, boolean caseInsensitiveKeys) {
     if (unmapped) {
       return;
     }
     if (aliases != null) {
       for (final String alias : aliases) {
-        writer.append("        case \"%s\":", alias);
-        writer.eol();
+        String propertyKey = caseInsensitiveKeys ? alias.toLowerCase() : alias;
+        writer.append("        case \"%s\":", propertyKey).eol();
       }
     }
-    writer.append("        case \"%s\": {", propertyName).eol();
+    String propertyKey = caseInsensitiveKeys ? propertyName.toLowerCase() : propertyName;
+    writer.append("        case \"%s\": {", propertyKey).eol();
     if (!deserialize) {
       writer.append("          reader.skipValue();");
     } else if (defaultConstructor) {

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

@@ -10,18 +10,23 @@ class NamingConventionReader {
   private static final String JSON_ANNOTATION = "io.avaje.jsonb.Json";
   private static final String NAMING_ATTRIBUTE = "naming()";
   private static final String TYPEPROPERTY_ATTRIBUTE = "typeProperty()";
+  private static final String CASEINSENSITIVEKEYS_ATTRIBUTE = "caseInsensitiveKeys()";
 
   private String typeProperty;
+  private boolean caseInsensitiveKeys;
   private NamingConvention namingConvention;
 
   NamingConventionReader(TypeElement element) {
     for (AnnotationMirror mirror : element.getAnnotationMirrors()) {
       if (JSON_ANNOTATION.equals(mirror.getAnnotationType().toString())) {
         for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : mirror.getElementValues().entrySet()) {
-          if (entry.getKey().toString().equals(NAMING_ATTRIBUTE)) {
+          String key = entry.getKey().toString();
+          if (key.equals(NAMING_ATTRIBUTE)) {
             namingConvention = NamingConvention.of(naming(entry.getValue().toString()));
-          } else if (entry.getKey().toString().equals(TYPEPROPERTY_ATTRIBUTE)) {
+          } else if (key.equals(TYPEPROPERTY_ATTRIBUTE)) {
             typeProperty = Util.trimQuotes(entry.getValue().toString());
+          } else if (key.equals(CASEINSENSITIVEKEYS_ATTRIBUTE)) {
+            caseInsensitiveKeys = Boolean.parseBoolean(entry.getValue().toString());
           }
         }
       }
@@ -43,4 +48,8 @@ NamingConvention get() {
   String typeProperty() {
     return typeProperty != null ? typeProperty : "@type";
   }
+
+  boolean isCaseInsensitiveKeys() {
+    return caseInsensitiveKeys;
+  }
 }

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

@@ -46,6 +46,11 @@
    */
   String typeProperty() default "";
 
+  /**
+   * When set to true on deserialization keys are matched insensitive to case.
+   */
+  boolean caseInsensitiveKeys() default false;
+
   /**
    * Specify types to generate JsonAdapters for.
    * <p>