feat!: Schema query is optional

Author: NeedleInAJayStack

Sources/GraphQL/Execution/Execute.swift

@@ -466,7 +466,14 @@ func getOperationRootType(
 ) throws -> GraphQLObjectType {
     switch operation.operation {
     case .query:
-        return schema.queryType
+        guard let queryType = schema.queryType else {
+            throw GraphQLError(
+                message: "Schema is not configured for queries",
+                nodes: [operation]
+            )
+        }
+
+        return queryType
     case .mutation:
         guard let mutationType = schema.mutationType else {
             throw GraphQLError(
@@ -1213,9 +1220,9 @@ func getFieldDef(
     parentType: GraphQLObjectType,
     fieldName: String
 ) throws -> GraphQLFieldDefinition {
-    if fieldName == SchemaMetaFieldDef.name, schema.queryType.name == parentType.name {
+    if fieldName == SchemaMetaFieldDef.name, schema.queryType?.name == parentType.name {
         return SchemaMetaFieldDef
-    } else if fieldName == TypeMetaFieldDef.name, schema.queryType.name == parentType.name {
+    } else if fieldName == TypeMetaFieldDef.name, schema.queryType?.name == parentType.name {
         return TypeMetaFieldDef
     } else if fieldName == TypeNameMetaFieldDef.name {
         return TypeNameMetaFieldDef

Sources/GraphQL/Type/Schema.swift

@@ -26,7 +26,7 @@
  *
  */
 public final class GraphQLSchema {
-    public let queryType: GraphQLObjectType
+    public let queryType: GraphQLObjectType?
     public let mutationType: GraphQLObjectType?
     public let subscriptionType: GraphQLObjectType?
     public let directives: [GraphQLDirective]
@@ -35,7 +35,7 @@ public final class GraphQLSchema {
     private var subTypeMap: [String: [String: Bool]] = [:]
 
     public init(
-        query: GraphQLObjectType,
+        query: GraphQLObjectType? = nil,
         mutation: GraphQLObjectType? = nil,
         subscription: GraphQLObjectType? = nil,
         types: [GraphQLNamedType] = [],
@@ -49,9 +49,11 @@ public final class GraphQLSchema {
         self.directives = directives.isEmpty ? specifiedDirectives : directives
 
         // Build type map now to detect any errors within this schema.
-        var initialTypes: [GraphQLNamedType] = [
-            queryType,
-        ]
+        var initialTypes: [GraphQLNamedType] = []
+        
+        if let query = queryType {
+            initialTypes.append(query)
+        }
 
         if let mutation = mutationType {
             initialTypes.append(mutation)

Sources/GraphQL/Utilities/TypeInfo.swift

@@ -238,11 +238,11 @@ func getFieldDef(
     let name = fieldAST.name.value
 
     if let parentType = parentType as? GraphQLNamedType {
-        if name == SchemaMetaFieldDef.name, schema.queryType.name == parentType.name {
+        if name == SchemaMetaFieldDef.name, schema.queryType?.name == parentType.name {
             return SchemaMetaFieldDef
         }
 
-        if name == TypeMetaFieldDef.name, schema.queryType.name == parentType.name {
+        if name == TypeMetaFieldDef.name, schema.queryType?.name == parentType.name {
             return TypeMetaFieldDef
         }
     }