Fix a crash when combining generics and records (#1442)

Without the fix the test fails like so:

    No JsonAdapter for T (with no annotations)
    for T
    for java.util.List<T>
    for com.squareup.moshi.records.RecordsTest$IndirectGenerics<java.lang.Long>
    for class com.squareup.moshi.records.RecordsTest$HasIndirectGenerics
    java.lang.IllegalArgumentException: No JsonAdapter for T (with no annotations)
    for T
    for java.util.List<T>
    for com.squareup.moshi.records.RecordsTest$IndirectGenerics<java.lang.Long>
    for class com.squareup.moshi.records.RecordsTest$HasIndirectGenerics
      at com.squareup.moshi.Moshi$LookupChain.exceptionWithLookupStack(Moshi.java:389)
      at com.squareup.moshi.Moshi.adapter(Moshi.java:158)
      at com.squareup.moshi.Moshi.adapter(Moshi.java:106)
      at com.squareup.moshi.Moshi.adapter(Moshi.java:75)

moshi/records-tests/src/test/java/com/squareup/moshi/records/RecordsTest.java

@@ -156,6 +156,21 @@ public final class RecordsTest {
     assertThat(adapter.fromJson("{\"value\":4}")).isEqualTo(new GenericBoundedRecord<>(4));
   }
 
+  @Test
+  public void indirectGenerics() throws IOException {
+    var value =
+        new HasIndirectGenerics(
+            new IndirectGenerics<>(1L, List.of(2L, 3L, 4L), Map.of("five", 5L)));
+    var jsonAdapter = moshi.adapter(HasIndirectGenerics.class);
+    var json = "{\"value\":{\"single\":1,\"list\":[2,3,4],\"map\":{\"five\":5}}}";
+    assertThat(jsonAdapter.toJson(value)).isEqualTo(json);
+    assertThat(jsonAdapter.fromJson(json)).isEqualTo(value);
+  }
+
+  public static record IndirectGenerics<T>(T single, List<T> list, Map<String, T> map) {}
+
+  public static record HasIndirectGenerics(IndirectGenerics<Long> value) {}
+
   @Test
   public void qualifiedValues() throws IOException {
     var adapter = moshi.newBuilder().add(new ColorAdapter()).build().adapter(QualifiedValues.class);

moshi/src/main/java16/com/squareup/moshi/RecordJsonAdapter.java

@@ -17,6 +17,7 @@ package com.squareup.moshi;
 
 import static java.lang.invoke.MethodType.methodType;
 
+import com.squareup.moshi.internal.Util;
 import java.io.IOException;
 import java.lang.annotation.Annotation;
 import java.lang.invoke.MethodHandle;
@@ -24,8 +25,6 @@ import java.lang.invoke.MethodHandles;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.RecordComponent;
-import java.lang.reflect.Type;
-import java.lang.reflect.TypeVariable;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -54,39 +53,15 @@ final class RecordJsonAdapter<T> extends JsonAdapter<T> {
           return null;
         }
 
-        Map<String, Type> mappedTypeArgs = null;
-        if (type instanceof ParameterizedType parameterizedType) {
-          Type[] typeArgs = parameterizedType.getActualTypeArguments();
-          var typeVars = rawType.getTypeParameters();
-          mappedTypeArgs = new LinkedHashMap<>(typeArgs.length);
-          for (int i = 0; i < typeArgs.length; ++i) {
-            var typeVarName = typeVars[i].getName();
-            var materialized = typeArgs[i];
-            mappedTypeArgs.put(typeVarName, materialized);
-          }
-        }
         var components = rawType.getRecordComponents();
         var bindings = new LinkedHashMap<String, ComponentBinding<?>>();
-        var constructorParams = new Class<?>[components.length];
+        var componentRawTypes = new Class<?>[components.length];
         var lookup = MethodHandles.lookup();
         for (int i = 0, componentsLength = components.length; i < componentsLength; i++) {
           RecordComponent component = components[i];
-          constructorParams[i] = component.getType();
+          componentRawTypes[i] = component.getType();
           var name = component.getName();
-          var componentType = component.getGenericType();
+          var componentType = Util.resolve(type, rawType, component.getGenericType());
-          if (componentType instanceof TypeVariable<?> typeVariable) {
-            var typeVarName = typeVariable.getName();
-            if (mappedTypeArgs == null) {
-              throw new AssertionError(
-                  "No mapped type arguments found for type '" + typeVarName + "'");
-            }
-            var mappedType = mappedTypeArgs.get(typeVarName);
-            if (mappedType == null) {
-              throw new AssertionError(
-                  "No materialized type argument found for type '" + typeVarName + "'");
-            }
-            componentType = mappedType;
-          }
           var jsonName = name;
           Set<Annotation> qualifiers = null;
           for (var annotation : component.getDeclaredAnnotations()) {
@@ -129,7 +104,7 @@ final class RecordJsonAdapter<T> extends JsonAdapter<T> {
 
         MethodHandle constructor;
         try {
-          constructor = lookup.findConstructor(rawType, methodType(void.class, constructorParams));
+          constructor = lookup.findConstructor(rawType, methodType(void.class, componentRawTypes));
         } catch (NoSuchMethodException | IllegalAccessException e) {
           throw new AssertionError(e);
         }