Add test, use SortedSet in internal data classs

Author: rohandhruva

normalized-cache-apollo-compiler-plugin/src/main/kotlin/com/apollographql/cache/apollocompilerplugin/internal/AddKeyFieldsDocumentTransform.kt

@@ -109,7 +109,7 @@ internal object AddKeyFieldsExecutableDocumentTransform : ExecutableDocumentTran
     val parentTypeKeyFields = keyFields[parentType] ?: emptySet()
     newSelections.filterIsInstance<GQLField>().forEach {
       // Disallow fields whose alias conflicts with a key field, or is "__typename"
-      if (parentTypeKeyFields.contains(it.alias) || it.alias == "__typename") {
+      if (it.alias != null && (parentTypeKeyFields.contains(it.alias) || it.alias == "__typename")) {
         throw SourceAwareException(
             error = "Apollo: Field '${it.alias}: ${it.name}' in $parentType conflicts with key fields",
             sourceLocation = it.sourceLocation

normalized-cache-apollo-compiler-plugin/src/main/kotlin/com/apollographql/cache/apollocompilerplugin/internal/getTypePolicies.kt

@@ -7,9 +7,10 @@ import com.apollographql.apollo.ast.GQLTypeDefinition
 import com.apollographql.apollo.ast.Schema
 import com.apollographql.apollo.ast.Schema.Companion.TYPE_POLICY
 import com.apollographql.apollo.ast.SourceAwareException
+import java.util.SortedSet
 
 internal data class TypePolicy(
-    val keyFields: Set<String>,
+    val keyFields: SortedSet<String>,
     val embeddedFields: Set<String>,
 )
 
@@ -83,7 +84,7 @@ private fun Schema.validateAndComputeTypePolicy(
 
 private fun GQLDirective.toTypePolicy(): TypePolicy {
   return TypePolicy(
-      keyFields = extractFields("keyFields"),
+      keyFields = extractFields("keyFields").toSortedSet(),
       embeddedFields = extractFields("embeddedFields")
   )
 }

normalized-cache-apollo-compiler-plugin/src/test/kotlin/com/apollographql/cache/apollocompilerplugin/internal/GetTypePoliciesTest.kt

@@ -58,12 +58,43 @@ class GetTypePoliciesTest {
         ).getOrThrow()
 
     val expected = mapOf(
-        "User" to TypePolicy(keyFields = setOf("id"), embeddedFields = emptySet()),
-        "Animal" to TypePolicy(keyFields = setOf("kingdom", "species"), embeddedFields = emptySet()),
-        "Lion" to TypePolicy(keyFields = setOf("kingdom", "species"), embeddedFields = emptySet()),
-        "HasId" to TypePolicy(keyFields = setOf("id"), embeddedFields = emptySet()),
-        "Circle" to TypePolicy(keyFields = setOf("id"), embeddedFields = emptySet()),
-        "Square" to TypePolicy(keyFields = setOf("radius"), embeddedFields = emptySet()),
+        "User" to TypePolicy(keyFields = sortedSetOf("id"), embeddedFields = emptySet()),
+        "Animal" to TypePolicy(keyFields = sortedSetOf("kingdom", "species"), embeddedFields = emptySet()),
+        "Lion" to TypePolicy(keyFields = sortedSetOf("kingdom", "species"), embeddedFields = emptySet()),
+        "HasId" to TypePolicy(keyFields = sortedSetOf("id"), embeddedFields = emptySet()),
+        "Circle" to TypePolicy(keyFields = sortedSetOf("id"), embeddedFields = emptySet()),
+        "Square" to TypePolicy(keyFields = sortedSetOf("radius"), embeddedFields = emptySet()),
+    )
+
+    assertEquals(expected, schema.getTypePolicies())
+  }
+
+  @Test
+  fun ensureTypePolicyKeyFieldsAreSorted() {
+    // language=GraphQL
+    val schema = """
+      type Query {
+        animal: Animal
+      }
+      
+      type Animal @typePolicy(keyFields: "kingdom species genus class domain") {
+        kingdom: String!
+        species: String!
+        genus: String!
+        domain: String!
+        class: String!
+      }
+    """.trimIndent()
+        .parseAsGQLDocument().getOrThrow()
+        .validateAsSchema(
+            SchemaValidationOptions(
+                addKotlinLabsDefinitions = true,
+                foreignSchemas = emptyList()
+            )
+        ).getOrThrow()
+
+    val expected = mapOf(
+        "Animal" to TypePolicy(keyFields = sortedSetOf("class", "domain", "genus", "kingdom", "species"), embeddedFields = emptySet()),
     )
 
     assertEquals(expected, schema.getTypePolicies())