Rename FieldDescriptorOrUnknown to SubScopeId

RELNOTES=n/a
PiperOrigin-RevId: 369285049

9 files changed, 107 insertions, 151 deletions

diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/AnyUtils.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/AnyUtils.java
index 32037ad3..a9a7782e 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/AnyUtils.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/AnyUtils.java
@@ -35,11 +35,10 @@ class AnyUtils {
     return TYPE_URL_FIELD_DESCRIPTOR;
   }
 
-  private static final FieldDescriptorOrUnknown TYPE_URL_FIELD_DESCRIPTOR_OR_UNKNOWN =
-      FieldDescriptorOrUnknown.of(TYPE_URL_FIELD_DESCRIPTOR);
+  private static final SubScopeId TYPE_URL_SUB_SCOPE_ID = SubScopeId.of(TYPE_URL_FIELD_DESCRIPTOR);
 
-  static FieldDescriptorOrUnknown typeUrlFieldDescriptorOrUnknown() {
-    return TYPE_URL_FIELD_DESCRIPTOR_OR_UNKNOWN;
+  static SubScopeId typeUrlSubScopeId() {
+    return TYPE_URL_SUB_SCOPE_ID;
   }
 
   private static final FieldDescriptor VALUE_FIELD_DESCRIPTOR =
@@ -49,11 +48,10 @@ class AnyUtils {
     return VALUE_FIELD_DESCRIPTOR;
   }
 
-  private static final FieldDescriptorOrUnknown VALUE_FIELD_DESCRIPTOR_OR_UNKNOWN =
-      FieldDescriptorOrUnknown.of(VALUE_FIELD_DESCRIPTOR);
+  private static final SubScopeId VALUE_SUB_SCOPE_ID = SubScopeId.of(VALUE_FIELD_DESCRIPTOR);
 
-  static FieldDescriptorOrUnknown valueFieldDescriptorOrUnknown() {
-    return VALUE_FIELD_DESCRIPTOR_OR_UNKNOWN;
+  static SubScopeId valueSubScopeId() {
+    return VALUE_SUB_SCOPE_ID;
   }
 
   /** Unpack an `Any` proto using the TypeRegistry and ExtensionRegistry on `config`. */
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/DiffResult.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/DiffResult.java
index b72c69d1..a0ec9373 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/DiffResult.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/DiffResult.java
@@ -56,7 +56,7 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
   @AutoValue
   abstract static class SingularField extends RecursableDiffEntity.WithResultCode {
     /** The type information for this field. May be absent if result code is {@code IGNORED}. */
-    abstract Optional<FieldDescriptorOrUnknown> fieldDescriptorOrUnknown();
+    abstract Optional<SubScopeId> subScopeId();
 
     /** The display name for this field. May include an array-index specifier. */
     abstract String fieldName();
@@ -110,7 +110,7 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
           if (actual().get() instanceof Message) {
             sb.append("\n").append(actual().get());
           } else {
-            sb.append(valueString(fieldDescriptorOrUnknown().get(), actual().get())).append("\n");
+            sb.append(valueString(subScopeId().get(), actual().get())).append("\n");
           }
           return;
         case IGNORED:
@@ -123,7 +123,7 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
             printChildContents(includeMatches, fieldPrefix, sb);
           } else {
             sb.append(": ")
-                .append(valueString(fieldDescriptorOrUnknown().get(), actualOrExpected()))
+                .append(valueString(subScopeId().get(), actualOrExpected()))
                 .append("\n");
           }
           return;
@@ -134,9 +134,9 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
             printChildContents(includeMatches, fieldPrefix, sb);
           } else {
             sb.append(": ")
-                .append(valueString(fieldDescriptorOrUnknown().get(), expected().get()))
+                .append(valueString(subScopeId().get(), expected().get()))
                 .append(" -> ")
-                .append(valueString(fieldDescriptorOrUnknown().get(), actual().get()))
+                .append(valueString(subScopeId().get(), actual().get()))
                 .append("\n");
           }
           return;
@@ -145,7 +145,7 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
           if (expected().get() instanceof Message) {
             sb.append("\n").append(expected().get());
           } else {
-            sb.append(valueString(fieldDescriptorOrUnknown().get(), expected().get())).append("\n");
+            sb.append(valueString(subScopeId().get(), expected().get())).append("\n");
           }
           return;
         default:
@@ -172,8 +172,7 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
     abstract static class Builder {
       abstract Builder setResult(Result result);
 
-      abstract Builder setFieldDescriptorOrUnknown(
-          FieldDescriptorOrUnknown fieldDescriptorOrUnknown);
+      abstract Builder setSubScopeId(SubScopeId subScopeId);
 
       abstract Builder setFieldName(String fieldName);
 
@@ -600,14 +599,14 @@ abstract class DiffResult extends RecursableDiffEntity.WithoutResultCode {
     return rootFieldPrefix.isEmpty() ? toAdd : (rootFieldPrefix + "." + toAdd);
   }
 
-  private static String valueString(FieldDescriptorOrUnknown fieldDescriptorOrUnknown, Object o) {
-    switch (fieldDescriptorOrUnknown.kind()) {
+  private static String valueString(SubScopeId subScopeId, Object o) {
+    switch (subScopeId.kind()) {
       case FIELD_DESCRIPTOR:
-        return valueString(fieldDescriptorOrUnknown.fieldDescriptor(), o);
+        return valueString(subScopeId.fieldDescriptor(), o);
       case UNKNOWN_FIELD_DESCRIPTOR:
-        return valueString(fieldDescriptorOrUnknown.unknownFieldDescriptor(), o);
+        return valueString(subScopeId.unknownFieldDescriptor(), o);
     }
-    throw new AssertionError(fieldDescriptorOrUnknown.kind());
+    throw new AssertionError(subScopeId.kind());
   }
 
   private static String valueString(FieldDescriptor fieldDescriptor, Object o) {
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldNumberTree.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldNumberTree.java
index 4e9dbe53..d33e2fee 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldNumberTree.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldNumberTree.java
@@ -40,7 +40,7 @@ final class FieldNumberTree {
   }
 
   // Modified only during [factory] construction, never changed afterwards.
-  private final Map<FieldDescriptorOrUnknown, FieldNumberTree> children = Maps.newHashMap();
+  private final Map<SubScopeId, FieldNumberTree> children = Maps.newHashMap();
 
   /** Returns whether this {@code FieldNumberTree} has no children. */
   boolean isEmpty() {
@@ -52,14 +52,14 @@ final class FieldNumberTree {
    *
    * <p>{@code empty()} if there is none.
    */
-  FieldNumberTree child(FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-    FieldNumberTree child = children.get(fieldDescriptorOrUnknown);
+  FieldNumberTree child(SubScopeId subScopeId) {
+    FieldNumberTree child = children.get(subScopeId);
     return child == null ? EMPTY : child;
   }
 
   /** Returns whether this tree has a child for this node. */
-  boolean hasChild(FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-    return children.containsKey(fieldDescriptorOrUnknown);
+  boolean hasChild(SubScopeId subScopeId) {
+    return children.containsKey(subScopeId);
   }
 
   static FieldNumberTree fromMessage(Message message) {
@@ -68,9 +68,9 @@ final class FieldNumberTree {
     // Known fields.
     Map<FieldDescriptor, Object> knownFieldValues = message.getAllFields();
     for (FieldDescriptor field : knownFieldValues.keySet()) {
-      FieldDescriptorOrUnknown fieldDescriptorOrUnknown = FieldDescriptorOrUnknown.of(field);
+      SubScopeId subScopeId = SubScopeId.of(field);
       FieldNumberTree childTree = new FieldNumberTree();
-      tree.children.put(fieldDescriptorOrUnknown, childTree);
+      tree.children.put(subScopeId, childTree);
 
       Object fieldValue = knownFieldValues.get(field);
       if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
@@ -107,10 +107,9 @@ final class FieldNumberTree {
       UnknownFieldSet.Field unknownField = unknownFieldSet.asMap().get(fieldNumber);
       for (UnknownFieldDescriptor unknownFieldDescriptor :
           UnknownFieldDescriptor.descriptors(fieldNumber, unknownField)) {
-        FieldDescriptorOrUnknown fieldDescriptorOrUnknown =
-            FieldDescriptorOrUnknown.of(unknownFieldDescriptor);
+        SubScopeId subScopeId = SubScopeId.of(unknownFieldDescriptor);
         FieldNumberTree childTree = new FieldNumberTree();
-        tree.children.put(fieldDescriptorOrUnknown, childTree);
+        tree.children.put(subScopeId, childTree);
 
         if (unknownFieldDescriptor.type() == UnknownFieldDescriptor.Type.GROUP) {
           for (Object group : unknownFieldDescriptor.type().getValues(unknownField)) {
@@ -125,12 +124,12 @@ final class FieldNumberTree {
 
   /** Adds the other tree onto this one. May destroy {@code other} in the process. */
   private void merge(FieldNumberTree other) {
-    for (FieldDescriptorOrUnknown fieldDescriptorOrUnknown : other.children.keySet()) {
-      FieldNumberTree value = other.children.get(fieldDescriptorOrUnknown);
-      if (!this.children.containsKey(fieldDescriptorOrUnknown)) {
-        this.children.put(fieldDescriptorOrUnknown, value);
+    for (SubScopeId subScopeId : other.children.keySet()) {
+      FieldNumberTree value = other.children.get(subScopeId);
+      if (!this.children.containsKey(subScopeId)) {
+        this.children.put(subScopeId, value);
       } else {
-        this.children.get(fieldDescriptorOrUnknown).merge(value);
+        this.children.get(subScopeId).merge(value);
       }
     }
   }
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogic.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogic.java
index 30204ea9..31fd0563 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogic.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogic.java
@@ -49,13 +49,11 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
    * Returns whether the given field is included in this FieldScopeLogic, along with whether it's
    * included recursively or not.
    */
-  abstract FieldScopeResult policyFor(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown);
+  abstract FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId);
 
   /** Returns whether the given field is included in this FieldScopeLogic. */
-  final boolean contains(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-    return policyFor(rootDescriptor, fieldDescriptorOrUnknown).included();
+  final boolean contains(Descriptor rootDescriptor, SubScopeId subScopeId) {
+    return policyFor(rootDescriptor, subScopeId).included();
   }
 
   /**
@@ -65,13 +63,12 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
    * #subScopeImpl} to implement those cases.
    */
   @Override
-  public final FieldScopeLogic subScope(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-    FieldScopeResult result = policyFor(rootDescriptor, fieldDescriptorOrUnknown);
+  public final FieldScopeLogic subScope(Descriptor rootDescriptor, SubScopeId subScopeId) {
+    FieldScopeResult result = policyFor(rootDescriptor, subScopeId);
     if (result.recursive()) {
       return result.included() ? all() : none();
     } else {
-      return subScopeImpl(rootDescriptor, fieldDescriptorOrUnknown);
+      return subScopeImpl(rootDescriptor, subScopeId);
     }
   }
 
@@ -82,8 +79,7 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
    * {@code NONRECURSIVE} results must override this method.
    */
   @ForOverride
-  FieldScopeLogic subScopeImpl(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+  FieldScopeLogic subScopeImpl(Descriptor rootDescriptor, SubScopeId subScopeId) {
     throw new UnsupportedOperationException("subScopeImpl not implemented for " + getClass());
   }
 
@@ -178,8 +174,7 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
         }
 
         @Override
-        final FieldScopeResult policyFor(
-            Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+        final FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
           return FieldScopeResult.INCLUDED_RECURSIVELY;
         }
 
@@ -197,8 +192,7 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
         }
 
         @Override
-        final FieldScopeResult policyFor(
-            Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+        final FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
           return FieldScopeResult.EXCLUDED_RECURSIVELY;
         }
       };
@@ -226,17 +220,15 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     }
 
     @Override
-    final FieldScopeResult policyFor(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-      return fieldNumberTree.hasChild(fieldDescriptorOrUnknown)
+    final FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
+      return fieldNumberTree.hasChild(subScopeId)
           ? FieldScopeResult.INCLUDED_NONRECURSIVELY
           : FieldScopeResult.EXCLUDED_RECURSIVELY;
     }
 
     @Override
-    final FieldScopeLogic subScopeImpl(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-      return newPartialScopeLogic(fieldNumberTree.child(fieldDescriptorOrUnknown));
+    final FieldScopeLogic subScopeImpl(Descriptor rootDescriptor, SubScopeId subScopeId) {
+      return newPartialScopeLogic(fieldNumberTree.child(subScopeId));
     }
 
     private static PartialScopeLogic newPartialScopeLogic(FieldNumberTree fieldNumberTree) {
@@ -311,14 +303,12 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     abstract boolean matchesFieldDescriptor(Descriptor descriptor, FieldDescriptor fieldDescriptor);
 
     @Override
-    final FieldScopeResult policyFor(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-      if (fieldDescriptorOrUnknown.kind()
-          == FieldDescriptorOrUnknown.Kind.UNKNOWN_FIELD_DESCRIPTOR) {
+    final FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
+      if (subScopeId.kind() == SubScopeId.Kind.UNKNOWN_FIELD_DESCRIPTOR) {
         return FieldScopeResult.EXCLUDED_RECURSIVELY;
       }
 
-      FieldDescriptor fieldDescriptor = fieldDescriptorOrUnknown.fieldDescriptor();
+      FieldDescriptor fieldDescriptor = subScopeId.fieldDescriptor();
       if (matchesFieldDescriptor(rootDescriptor, fieldDescriptor)) {
         return FieldScopeResult.of(/* included = */ true, isRecursive);
       }
@@ -332,8 +322,7 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     }
 
     @Override
-    final FieldScopeLogic subScopeImpl(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+    final FieldScopeLogic subScopeImpl(Descriptor rootDescriptor, SubScopeId subScopeId) {
       return this;
     }
 
@@ -443,12 +432,11 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     abstract T newLogicOfSameType(List<FieldScopeLogic> newElements);
 
     @Override
-    final FieldScopeLogic subScopeImpl(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+    final FieldScopeLogic subScopeImpl(Descriptor rootDescriptor, SubScopeId subScopeId) {
       ImmutableList.Builder<FieldScopeLogic> builder =
           ImmutableList.builderWithExpectedSize(elements.size());
       for (FieldScopeLogic elem : elements) {
-        builder.add(elem.subScope(rootDescriptor, fieldDescriptorOrUnknown));
+        builder.add(elem.subScope(rootDescriptor, subScopeId));
       }
       return newLogicOfSameType(builder.build());
     }
@@ -467,12 +455,11 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     }
 
     @Override
-    FieldScopeResult policyFor(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+    FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
       // The intersection of two scopes is ignorable if either scope is itself ignorable.
       return intersection(
-          elements.get(0).policyFor(rootDescriptor, fieldDescriptorOrUnknown),
-          elements.get(1).policyFor(rootDescriptor, fieldDescriptorOrUnknown));
+          elements.get(0).policyFor(rootDescriptor, subScopeId),
+          elements.get(1).policyFor(rootDescriptor, subScopeId));
     }
 
     private static FieldScopeResult intersection(
@@ -512,12 +499,11 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     }
 
     @Override
-    FieldScopeResult policyFor(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+    FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
       // The union of two scopes is ignorable only if both scopes are themselves ignorable.
       return union(
-          elements.get(0).policyFor(rootDescriptor, fieldDescriptorOrUnknown),
-          elements.get(1).policyFor(rootDescriptor, fieldDescriptorOrUnknown));
+          elements.get(0).policyFor(rootDescriptor, subScopeId),
+          elements.get(1).policyFor(rootDescriptor, subScopeId));
     }
 
     private static FieldScopeResult union(FieldScopeResult result1, FieldScopeResult result2) {
@@ -556,9 +542,8 @@ abstract class FieldScopeLogic implements FieldScopeLogicContainer<FieldScopeLog
     }
 
     @Override
-    FieldScopeResult policyFor(
-        Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
-      FieldScopeResult result = elements.get(0).policyFor(rootDescriptor, fieldDescriptorOrUnknown);
+    FieldScopeResult policyFor(Descriptor rootDescriptor, SubScopeId subScopeId) {
+      FieldScopeResult result = elements.get(0).policyFor(rootDescriptor, subScopeId);
       return FieldScopeResult.of(!result.included(), result.recursive());
     }
 
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicContainer.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicContainer.java
index 666112ef..e3d3ea4a 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicContainer.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicContainer.java
@@ -27,7 +27,7 @@ import com.google.protobuf.Descriptors.Descriptor;
 interface FieldScopeLogicContainer<T extends FieldScopeLogicContainer<T>> {
 
   /** Returns the analog of {@link FieldScopeLogic#subScope} for this container. */
-  T subScope(Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown);
+  T subScope(Descriptor rootDescriptor, SubScopeId subScopeId);
 
   /** Validates explicitly specified fields for this container. */
   void validate(Descriptor rootDescriptor, FieldDescriptorValidator fieldDescriptorValidator);
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicMap.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicMap.java
index f8579680..4bd0948d 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicMap.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldScopeLogicMap.java
@@ -61,11 +61,10 @@ class FieldScopeLogicMap<V> implements FieldScopeLogicContainer<FieldScopeLogicM
     return entries.isEmpty();
   }
 
-  public Optional<V> get(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+  public Optional<V> get(Descriptor rootDescriptor, SubScopeId subScopeId) {
     // Earlier entries override later ones, so we don't need to iterate backwards.
     for (Entry<V> entry : entries) {
-      if (entry.fieldScopeLogic().contains(rootDescriptor, fieldDescriptorOrUnknown)) {
+      if (entry.fieldScopeLogic().contains(rootDescriptor, subScopeId)) {
         return Optional.of(entry.value());
       }
     }
@@ -82,15 +81,12 @@ class FieldScopeLogicMap<V> implements FieldScopeLogicContainer<FieldScopeLogicM
   }
 
   @Override
-  public FieldScopeLogicMap<V> subScope(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+  public FieldScopeLogicMap<V> subScope(Descriptor rootDescriptor, SubScopeId subScopeId) {
     ImmutableList.Builder<Entry<V>> newEntries =
         ImmutableList.builderWithExpectedSize(entries.size());
     for (Entry<V> entry : entries) {
       newEntries.add(
-          Entry.of(
-              entry.fieldScopeLogic().subScope(rootDescriptor, fieldDescriptorOrUnknown),
-              entry.value()));
+          Entry.of(entry.fieldScopeLogic().subScope(rootDescriptor, subScopeId), entry.value()));
     }
     return new FieldScopeLogicMap<>(newEntries.build());
   }
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FluentEqualityConfig.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FluentEqualityConfig.java
index 4015238c..bd44f3e9 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FluentEqualityConfig.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FluentEqualityConfig.java
@@ -326,22 +326,16 @@ abstract class FluentEqualityConfig implements FieldScopeLogicContainer<FluentEq
   }
 
   @Override
-  public final FluentEqualityConfig subScope(
-      Descriptor rootDescriptor, FieldDescriptorOrUnknown fieldDescriptorOrUnknown) {
+  public final FluentEqualityConfig subScope(Descriptor rootDescriptor, SubScopeId subScopeId) {
     return toBuilder()
-        .setIgnoreFieldAbsenceScope(
-            ignoreFieldAbsenceScope().subScope(rootDescriptor, fieldDescriptorOrUnknown))
+        .setIgnoreFieldAbsenceScope(ignoreFieldAbsenceScope().subScope(rootDescriptor, subScopeId))
         .setIgnoreRepeatedFieldOrderScope(
-            ignoreRepeatedFieldOrderScope().subScope(rootDescriptor, fieldDescriptorOrUnknown))
+            ignoreRepeatedFieldOrderScope().subScope(rootDescriptor, subScopeId))
         .setIgnoreExtraRepeatedFieldElementsScope(
-            ignoreExtraRepeatedFieldElementsScope()
-                .subScope(rootDescriptor, fieldDescriptorOrUnknown))
-        .setDoubleCorrespondenceMap(
-            doubleCorrespondenceMap().subScope(rootDescriptor, fieldDescriptorOrUnknown))
-        .setFloatCorrespondenceMap(
-            floatCorrespondenceMap().subScope(rootDescriptor, fieldDescriptorOrUnknown))
-        .setCompareFieldsScope(
-            compareFieldsScope().subScope(rootDescriptor, fieldDescriptorOrUnknown))
+            ignoreExtraRepeatedFieldElementsScope().subScope(rootDescriptor, subScopeId))
+        .setDoubleCorrespondenceMap(doubleCorrespondenceMap().subScope(rootDescriptor, subScopeId))
+        .setFloatCorrespondenceMap(floatCorrespondenceMap().subScope(rootDescriptor, subScopeId))
+        .setCompareFieldsScope(compareFieldsScope().subScope(rootDescriptor, subScopeId))
         .build();
   }
 
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/ProtoTruthMessageDifferencer.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/ProtoTruthMessageDifferencer.java
index 7d069f19..d843a61d 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/ProtoTruthMessageDifferencer.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/ProtoTruthMessageDifferencer.java
@@ -104,10 +104,9 @@ final class ProtoTruthMessageDifferencer {
       // the field will be considered ignored in the final diff report if no sub-fields get compared
       // (i.e., the sub-DiffResult winds up empty). This allows us support FieldScopeLogic
       // disjunctions without repeating recursive work.
-      FieldDescriptorOrUnknown fieldDescriptorOrUnknown =
-          FieldDescriptorOrUnknown.of(fieldDescriptor);
+      SubScopeId subScopeId = SubScopeId.of(fieldDescriptor);
       FieldScopeResult shouldCompare =
-          config.compareFieldsScope().policyFor(rootDescriptor, fieldDescriptorOrUnknown);
+          config.compareFieldsScope().policyFor(rootDescriptor, subScopeId);
       if (shouldCompare == FieldScopeResult.EXCLUDED_RECURSIVELY) {
         builder.addSingularField(
             fieldDescriptor.getNumber(), SingularField.ignored(name(fieldDescriptor)));
@@ -128,19 +127,15 @@ final class ProtoTruthMessageDifferencer {
                   expectedMap,
                   actualAndExpectedKeys,
                   fieldDescriptor,
-                  config.subScope(rootDescriptor, fieldDescriptorOrUnknown)));
+                  config.subScope(rootDescriptor, subScopeId)));
         } else {
           List<?> actualList = toProtoList(actualFields.get(fieldDescriptor));
           List<?> expectedList = toProtoList(expectedFields.get(fieldDescriptor));
 
           boolean ignoreRepeatedFieldOrder =
-              config
-                  .ignoreRepeatedFieldOrderScope()
-                  .contains(rootDescriptor, fieldDescriptorOrUnknown);
+              config.ignoreRepeatedFieldOrderScope().contains(rootDescriptor, subScopeId);
           boolean ignoreExtraRepeatedFieldElements =
-              config
-                  .ignoreExtraRepeatedFieldElementsScope()
-                  .contains(rootDescriptor, fieldDescriptorOrUnknown);
+              config.ignoreExtraRepeatedFieldElementsScope().contains(rootDescriptor, subScopeId);
           if (ignoreRepeatedFieldOrder) {
             builder.addRepeatedField(
                 fieldDescriptor.getNumber(),
@@ -150,7 +145,7 @@ final class ProtoTruthMessageDifferencer {
                     shouldCompare == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                     fieldDescriptor,
                     ignoreExtraRepeatedFieldElements,
-                    config.subScope(rootDescriptor, fieldDescriptorOrUnknown)));
+                    config.subScope(rootDescriptor, subScopeId)));
           } else if (ignoreExtraRepeatedFieldElements && !expectedList.isEmpty()) {
             builder.addRepeatedField(
                 fieldDescriptor.getNumber(),
@@ -159,7 +154,7 @@ final class ProtoTruthMessageDifferencer {
                     expectedList,
                     shouldCompare == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                     fieldDescriptor,
-                    config.subScope(rootDescriptor, fieldDescriptorOrUnknown)));
+                    config.subScope(rootDescriptor, subScopeId)));
           } else {
             builder.addAllSingularFields(
                 fieldDescriptor.getNumber(),
@@ -168,7 +163,7 @@ final class ProtoTruthMessageDifferencer {
                     expectedList,
                     shouldCompare == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                     fieldDescriptor,
-                    config.subScope(rootDescriptor, fieldDescriptorOrUnknown)));
+                    config.subScope(rootDescriptor, subScopeId)));
           }
         }
       } else {
@@ -181,7 +176,7 @@ final class ProtoTruthMessageDifferencer {
                 shouldCompare == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                 fieldDescriptor,
                 name(fieldDescriptor),
-                config.subScope(rootDescriptor, fieldDescriptorOrUnknown)));
+                config.subScope(rootDescriptor, subScopeId)));
       }
     }
 
@@ -201,9 +196,7 @@ final class ProtoTruthMessageDifferencer {
 
     // Compare the TypeUrl fields.
     FieldScopeResult shouldCompareTypeUrl =
-        config
-            .compareFieldsScope()
-            .policyFor(rootDescriptor, AnyUtils.typeUrlFieldDescriptorOrUnknown());
+        config.compareFieldsScope().policyFor(rootDescriptor, AnyUtils.typeUrlSubScopeId());
     SingularField typeUrlDiffResult;
     if (!shouldCompareTypeUrl.included()) {
       typeUrlDiffResult = SingularField.ignored(name(AnyUtils.typeUrlFieldDescriptor()));
@@ -215,16 +208,14 @@ final class ProtoTruthMessageDifferencer {
               /* defaultValue= */ "",
               AnyUtils.typeUrlFieldDescriptor(),
               name(AnyUtils.typeUrlFieldDescriptor()),
-              config.subScope(rootDescriptor, AnyUtils.typeUrlFieldDescriptorOrUnknown()));
+              config.subScope(rootDescriptor, AnyUtils.typeUrlSubScopeId()));
     }
     builder.addSingularField(Any.TYPE_URL_FIELD_NUMBER, typeUrlDiffResult);
 
     // Try to unpack the value fields using the TypeRegister and url from the type_url field. If
     // that does not work then we revert to the original behaviour compare the bytes strings.
     FieldScopeResult shouldCompareValue =
-        config
-            .compareFieldsScope()
-            .policyFor(rootDescriptor, AnyUtils.valueFieldDescriptorOrUnknown());
+        config.compareFieldsScope().policyFor(rootDescriptor, AnyUtils.valueSubScopeId());
     SingularField valueDiffResult;
     if (shouldCompareValue == FieldScopeResult.EXCLUDED_RECURSIVELY) {
       valueDiffResult = SingularField.ignored(name(AnyUtils.valueFieldDescriptor()));
@@ -243,7 +234,7 @@ final class ProtoTruthMessageDifferencer {
                 shouldCompareValue == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                 AnyUtils.valueFieldDescriptor(),
                 name(AnyUtils.valueFieldDescriptor()),
-                config.subScope(rootDescriptor, AnyUtils.valueFieldDescriptorOrUnknown()));
+                config.subScope(rootDescriptor, AnyUtils.valueSubScopeId()));
       } else {
         valueDiffResult =
             compareSingularValue(
@@ -253,7 +244,7 @@ final class ProtoTruthMessageDifferencer {
                 shouldCompareValue == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                 AnyUtils.valueFieldDescriptor(),
                 name(AnyUtils.valueFieldDescriptor()),
-                config.subScope(rootDescriptor, AnyUtils.valueFieldDescriptorOrUnknown()));
+                config.subScope(rootDescriptor, AnyUtils.valueSubScopeId()));
       }
     }
     builder.addSingularField(Any.VALUE_FIELD_NUMBER, valueDiffResult);
@@ -314,12 +305,11 @@ final class ProtoTruthMessageDifferencer {
       FluentEqualityConfig mapConfig) {
     FieldDescriptor keyFieldDescriptor = mapFieldDescriptor.getMessageType().findFieldByNumber(1);
     FieldDescriptor valueFieldDescriptor = mapFieldDescriptor.getMessageType().findFieldByNumber(2);
-    FieldDescriptorOrUnknown valueFieldDescriptorOrUnknown =
-        FieldDescriptorOrUnknown.of(valueFieldDescriptor);
+    SubScopeId valueSubScopeId = SubScopeId.of(valueFieldDescriptor);
 
     // We never ignore the key, no matter what the logic dictates.
     FieldScopeResult compareValues =
-        mapConfig.compareFieldsScope().policyFor(rootDescriptor, valueFieldDescriptorOrUnknown);
+        mapConfig.compareFieldsScope().policyFor(rootDescriptor, valueSubScopeId);
     if (compareValues == FieldScopeResult.EXCLUDED_RECURSIVELY) {
       return ImmutableList.of(SingularField.ignored(name(mapFieldDescriptor)));
     }
@@ -327,10 +317,9 @@ final class ProtoTruthMessageDifferencer {
     boolean ignoreExtraRepeatedFieldElements =
         mapConfig
             .ignoreExtraRepeatedFieldElementsScope()
-            .contains(rootDescriptor, FieldDescriptorOrUnknown.of(mapFieldDescriptor));
+            .contains(rootDescriptor, SubScopeId.of(mapFieldDescriptor));
 
-    FluentEqualityConfig valuesConfig =
-        mapConfig.subScope(rootDescriptor, valueFieldDescriptorOrUnknown);
+    FluentEqualityConfig valuesConfig = mapConfig.subScope(rootDescriptor, valueSubScopeId);
 
     ImmutableList.Builder<SingularField> builder =
         ImmutableList.builderWithExpectedSize(actualAndExpectedKeys.size());
@@ -670,9 +659,7 @@ final class ProtoTruthMessageDifferencer {
 
     // Use the default if it's set and we're ignoring field absence.
     boolean ignoreFieldAbsence =
-        config
-            .ignoreFieldAbsenceScope()
-            .contains(rootDescriptor, FieldDescriptorOrUnknown.of(fieldDescriptor));
+        config.ignoreFieldAbsenceScope().contains(rootDescriptor, SubScopeId.of(fieldDescriptor));
     actual = orIfIgnoringFieldAbsence(actual, defaultValue, ignoreFieldAbsence);
     expected = orIfIgnoringFieldAbsence(expected, defaultValue, ignoreFieldAbsence);
 
@@ -698,7 +685,7 @@ final class ProtoTruthMessageDifferencer {
     // Report the full breakdown.
     SingularField.Builder singularFieldBuilder =
         SingularField.newBuilder()
-            .setFieldDescriptorOrUnknown(FieldDescriptorOrUnknown.of(fieldDescriptor))
+            .setSubScopeId(SubScopeId.of(fieldDescriptor))
             .setFieldName(fieldName)
             .setResult(result.build());
     if (actual != null) {
@@ -724,15 +711,14 @@ final class ProtoTruthMessageDifferencer {
 
     // Use the default if it's set and we're ignoring field absence, or if it's a Proto3 primitive
     // for which default is indistinguishable from unset.
-    FieldDescriptorOrUnknown fieldDescriptorOrUnknown =
-        FieldDescriptorOrUnknown.of(fieldDescriptor);
+    SubScopeId subScopeId = SubScopeId.of(fieldDescriptor);
     boolean isNonRepeatedProto3 =
         !fieldDescriptor.isRepeated()
             && fieldDescriptor.getContainingOneof() == null
             && fieldDescriptor.getFile().getSyntax() == Syntax.PROTO3;
     boolean ignoreFieldAbsence =
         isNonRepeatedProto3
-            || config.ignoreFieldAbsenceScope().contains(rootDescriptor, fieldDescriptorOrUnknown);
+            || config.ignoreFieldAbsenceScope().contains(rootDescriptor, subScopeId);
     actual = orIfIgnoringFieldAbsence(actual, defaultValue, ignoreFieldAbsence);
     expected = orIfIgnoringFieldAbsence(expected, defaultValue, ignoreFieldAbsence);
 
@@ -746,14 +732,14 @@ final class ProtoTruthMessageDifferencer {
             !doublesEqual(
                 (double) actual,
                 (double) expected,
-                config.doubleCorrespondenceMap().get(rootDescriptor, fieldDescriptorOrUnknown)
+                config.doubleCorrespondenceMap().get(rootDescriptor, subScopeId)
                 ));
       } else if (actual instanceof Float) {
         result.markModifiedIf(
             !floatsEqual(
                 (float) actual,
                 (float) expected,
-                config.floatCorrespondenceMap().get(rootDescriptor, fieldDescriptorOrUnknown)
+                config.floatCorrespondenceMap().get(rootDescriptor, subScopeId)
                 ));
       } else {
         result.markModifiedIf(!Objects.equal(actual, expected));
@@ -762,7 +748,7 @@ final class ProtoTruthMessageDifferencer {
 
     SingularField.Builder singularFieldBuilder =
         SingularField.newBuilder()
-            .setFieldDescriptorOrUnknown(FieldDescriptorOrUnknown.of(fieldDescriptor))
+            .setSubScopeId(SubScopeId.of(fieldDescriptor))
             .setFieldName(fieldName)
             .setResult(result.build());
     if (actual != null) {
@@ -818,10 +804,9 @@ final class ProtoTruthMessageDifferencer {
 
         UnknownFieldDescriptor unknownFieldDescriptor =
             UnknownFieldDescriptor.create(fieldNumber, type);
-        FieldDescriptorOrUnknown fieldDescriptorOrUnknown =
-            FieldDescriptorOrUnknown.of(unknownFieldDescriptor);
+        SubScopeId subScopeId = SubScopeId.of(unknownFieldDescriptor);
         FieldScopeResult compareFields =
-            config.compareFieldsScope().policyFor(rootDescriptor, fieldDescriptorOrUnknown);
+            config.compareFieldsScope().policyFor(rootDescriptor, subScopeId);
         if (compareFields == FieldScopeResult.EXCLUDED_RECURSIVELY) {
           builder.addSingularField(
               fieldNumber, SingularField.ignored(name(unknownFieldDescriptor)));
@@ -835,7 +820,7 @@ final class ProtoTruthMessageDifferencer {
                 expectedValues,
                 compareFields == FieldScopeResult.EXCLUDED_NONRECURSIVELY,
                 unknownFieldDescriptor,
-                config.subScope(rootDescriptor, fieldDescriptorOrUnknown)));
+                config.subScope(rootDescriptor, subScopeId)));
       }
     }
 
@@ -917,7 +902,7 @@ final class ProtoTruthMessageDifferencer {
     // Report the full breakdown.
     SingularField.Builder singularFieldBuilder =
         SingularField.newBuilder()
-            .setFieldDescriptorOrUnknown(FieldDescriptorOrUnknown.of(unknownFieldDescriptor))
+            .setSubScopeId(SubScopeId.of(unknownFieldDescriptor))
             .setFieldName(fieldName)
             .setResult(result.build());
     if (actual != null) {
@@ -945,7 +930,7 @@ final class ProtoTruthMessageDifferencer {
 
     SingularField.Builder singularFieldBuilder =
         SingularField.newBuilder()
-            .setFieldDescriptorOrUnknown(FieldDescriptorOrUnknown.of(unknownFieldDescriptor))
+            .setSubScopeId(SubScopeId.of(unknownFieldDescriptor))
             .setFieldName(fieldName)
             .setResult(result.build());
     if (actual != null) {
diff --git a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldDescriptorOrUnknown.java b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/SubScopeId.java
index 5f5b1b64..4860969e 100644
--- a/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/FieldDescriptorOrUnknown.java
+++ b/extensions/proto/src/main/java/com/google/common/truth/extensions/proto/SubScopeId.java
@@ -19,8 +19,8 @@ package com.google.common.truth.extensions.proto;
 import com.google.auto.value.AutoOneOf;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 
-@AutoOneOf(FieldDescriptorOrUnknown.Kind.class)
-abstract class FieldDescriptorOrUnknown {
+@AutoOneOf(SubScopeId.Kind.class)
+abstract class SubScopeId {
   enum Kind {
     FIELD_DESCRIPTOR,
     UNKNOWN_FIELD_DESCRIPTOR;
@@ -45,11 +45,11 @@ abstract class FieldDescriptorOrUnknown {
     throw new AssertionError(kind());
   }
 
-  static FieldDescriptorOrUnknown of(FieldDescriptor fieldDescriptor) {
-    return AutoOneOf_FieldDescriptorOrUnknown.fieldDescriptor(fieldDescriptor);
+  static SubScopeId of(FieldDescriptor fieldDescriptor) {
+    return AutoOneOf_SubScopeId.fieldDescriptor(fieldDescriptor);
   }
 
-  static FieldDescriptorOrUnknown of(UnknownFieldDescriptor unknownFieldDescriptor) {
-    return AutoOneOf_FieldDescriptorOrUnknown.unknownFieldDescriptor(unknownFieldDescriptor);
+  static SubScopeId of(UnknownFieldDescriptor unknownFieldDescriptor) {
+    return AutoOneOf_SubScopeId.unknownFieldDescriptor(unknownFieldDescriptor);
   }
 }