Support simple list cases in FieldPolicyCacheResolver

normalized-cache/src/commonMain/kotlin/com/apollographql/cache/normalized/api/CacheResolver.kt

@@ -1,6 +1,8 @@
 package com.apollographql.cache.normalized.api
 
 import com.apollographql.apollo.api.CompiledField
+import com.apollographql.apollo.api.CompiledListType
+import com.apollographql.apollo.api.CompiledNotNullType
 import com.apollographql.apollo.api.Executable
 import com.apollographql.apollo.api.MutableExecutionOptions
 import com.apollographql.apollo.exception.CacheMissException
@@ -230,12 +232,28 @@ class CacheControlCacheResolver(
  */
 object FieldPolicyCacheResolver : CacheResolver {
   override fun resolveField(context: ResolverContext): Any? {
-    val keyArgsValues = context.field.argumentValues(context.variables) { it.definition.isKey }.values.map { it.toString() }
-
-    if (keyArgsValues.isNotEmpty()) {
-      return CacheKey(context.field.type.rawType().name, keyArgsValues)
+    val keyArgsValues = context.field.argumentValues(context.variables) { it.definition.isKey }.values
+    if (keyArgsValues.isEmpty()) {
+      return DefaultCacheResolver.resolveField(context)
     }
-
-    return DefaultCacheResolver.resolveField(context)
+    var type = context.field.type
+    if (type is CompiledNotNullType) {
+      type = type.ofType
+    }
+    if (type is CompiledListType) {
+      // Only support flat lists
+      if (type.ofType !is CompiledListType && !(type.ofType is CompiledNotNullType && (type.ofType as CompiledNotNullType).ofType is CompiledListType)) {
+        // Only support single key argument which is a flat list
+        if (keyArgsValues.size == 1) {
+          val keyArgsValue = keyArgsValues.first() as? List<*>
+          if (keyArgsValue != null && keyArgsValue.firstOrNull() !is List<*>) {
+            return keyArgsValue.map {
+              CacheKey(type.rawType().name, it.toString())
+            }
+          }
+        }
+      }
+    }
+    return CacheKey(type.rawType().name, keyArgsValues.map { it.toString() })
   }
 }

tests/normalized-cache/src/commonMain/graphql/declarativecache/extra.graphqls

@@ -2,7 +2,10 @@ extend type Author @typePolicy(keyFields: "firstName lastName")
 
 extend type Book @typePolicy(keyFields: "isbn")
 
-extend type Query @fieldPolicy(forField: "book", keyArgs: "isbn") @fieldPolicy(forField: "author", keyArgs: "firstName lastName")
+extend type Query
+@fieldPolicy(forField: "book", keyArgs: "isbn")
+@fieldPolicy(forField: "author", keyArgs: "firstName lastName")
+@fieldPolicy(forField: "books", keyArgs: "isbns")
 
 interface Node @typePolicy(keyFields: "id") {
   id: ID!

tests/normalized-cache/src/commonTest/kotlin/declarativecache/DeclarativeCacheTest.kt

@@ -91,6 +91,20 @@ class DeclarativeCacheTest {
     assertEquals("Bordage", authorData2.author?.lastName)
   }
 
+  @Test
+  fun fieldPolicyWithLists() = runTest {
+    val cacheManager = CacheManager(MemoryCacheFactory())
+    cacheManager.writeOperation(GetPromoBookQuery(), GetPromoBookQuery.Data(GetPromoBookQuery.PromoBook(title = "Promo", isbn = "42", __typename = "Book")))
+    cacheManager.writeOperation(GetOtherBookQuery(), GetOtherBookQuery.Data(GetOtherBookQuery.OtherBook(isbn = "43", title = "Other Book", __typename = "Book")))
+
+    val booksQuery = GetBooksQuery(listOf("42", "43"))
+    val booksCacheResponse = cacheManager.readOperation(booksQuery)
+    val booksData = booksCacheResponse.data!!
+    assertEquals(2, booksData.books.size)
+    assertEquals(GetBooksQuery.Book("Promo", "42", "Book"), booksData.books[0])
+    assertEquals(GetBooksQuery.Book("Other Book", "43", "Book"), booksData.books[1])
+  }
+
   @Test
   fun canResolveListProgrammatically() = runTest {
     val cacheResolver = object : CacheResolver {