Do not merge inline fragments with directives (#3189)

* [compat] Fix inline fragments with include directive

Even if these inline fragments have the same type condition as their
parent type, we can't merge them as the nullability status of their
fields might be different

Closes #2796

* Compound -> Composite

* update test fixtures

apollo-api/src/commonMain/kotlin/com/apollographql/apollo3/api/CompiledGraphQL.kt

@@ -188,7 +188,7 @@ val CompiledBooleanType = ScalarType("Boolean")
 @SharedImmutable
 val CompiledIDType = ScalarType("ID")
 
-fun CompiledNamedType.isCompound(): Boolean {
+fun CompiledNamedType.isComposite(): Boolean {
   return when (this) {
     is UnionType,
     is InterfaceType,

apollo-compiler/src/main/kotlin/com/apollographql/apollo3/compiler/ir/OperationBasedModelGroupBuilder.kt

@@ -190,37 +190,50 @@ internal class OperationBasedModelGroupBuilder(
      */
     val inlineFragmentsFields = selections.map { it.selection }.filterIsInstance<GQLInlineFragment>()
         .groupBy {
-          InlineFragmentKey(it.typeCondition.name, it.directives.toBooleanExpression())
-        }.entries.map { entry ->
-          val inlineFragmentsWithSameKey = entry.value
-          val typeCondition = entry.key.typeCondition
-          val prefix = if (collectAllInlineFragmentFields) "as" else "on"
-
-          val childInfo = IrFieldInfo(
-              responseName = "$prefix${entry.key.toName()}",
-              description = "Synthetic field for inline fragment on $typeCondition",
-              deprecationReason = null,
-              type = IrModelType(IrUnknownModelId)
-          )
-
-          val possibleTypes = schema.possibleTypes(typeCondition)
-          val childCondition = entry.key.condition.and(BooleanExpression.Element(BPossibleTypes(possibleTypes))).simplify()
-
-          val childSelections = inlineFragmentsWithSameKey.flatMap {
-            it.selectionSet.selections.map { SelectionWithParent(it, typeCondition) }
-          }.toMutableList()
-          if (collectAllInlineFragmentFields) {
-            childSelections.addAll(selections.filter { it.selection is GQLField})
-          }
-
-          buildField(
-              root = root,
-              path = selfPath,
-              info = childInfo,
-              selections = childSelections,
-              condition = childCondition,
-              isSynthetic = true
-          )
+          it.typeCondition.name
+        }.entries.flatMap {
+          val typeCondition = it.key
+
+          // If there is only one fragment, no need to disambiguate it
+          val nameNeedsCondition = it.value.size > 1
+
+          it.value.groupBy { it.directives.toBooleanExpression() }
+              .entries.map { entry ->
+                val prefix = if (collectAllInlineFragmentFields) "as" else "on"
+
+                val name = if (nameNeedsCondition) {
+                  InlineFragmentKey(typeCondition, entry.key).toName()
+                } else {
+                  InlineFragmentKey(typeCondition, BooleanExpression.True).toName()
+                }
+
+                val childInfo = IrFieldInfo(
+                    responseName = "$prefix$name",
+                    description = "Synthetic field for inline fragment on $typeCondition",
+                    deprecationReason = null,
+                    type = IrModelType(IrUnknownModelId)
+                )
+
+                val possibleTypes = schema.possibleTypes(typeCondition)
+                val childCondition = entry.key.and(BooleanExpression.Element(BPossibleTypes(possibleTypes))).simplify()
+
+                var childSelections = entry.value.flatMap {
+                  it.selectionSet.selections.map { SelectionWithParent(it, typeCondition) }
+                }
+
+                if (collectAllInlineFragmentFields) {
+                  childSelections = selections.filter { it.selection is GQLField} + childSelections
+                }
+
+                buildField(
+                    root = root,
+                    path = selfPath,
+                    info = childInfo,
+                    selections = childSelections,
+                    condition = childCondition,
+                    isSynthetic = true
+                )
+              }
         }
 
     /**