chore: refactor normalization factory (#528)

composition/src/ast/ast.ts

@@ -23,8 +23,8 @@ import {
   TypeNode,
   UnionTypeDefinitionNode,
 } from 'graphql';
-import { federationUnexpectedNodeKindError } from '../errors/errors';
 import { formatDescription } from './utils';
+import { deepCopyTypeNode } from '../schema-building/ast';
 
 function deepCopyFieldsAndInterfaces(
   node: InterfaceTypeDefinitionNode | ObjectTypeDefinitionNode | ObjectTypeExtensionNode,
@@ -50,33 +50,6 @@ export type ConstValueNodeWithValue =
   | BooleanValueNode
   | EnumValueNode;
 
-export function deepCopyTypeNode(node: TypeNode, parentName: string, fieldName: string): TypeNode {
-  const deepCopy: MutableTypeNode = { kind: node.kind };
-  let lastTypeNode = deepCopy;
-  for (let i = 0; i < maximumTypeNesting; i++) {
-    switch (node.kind) {
-      case Kind.NAMED_TYPE:
-        lastTypeNode.name = { ...node.name };
-        return deepCopy as TypeNode;
-      case Kind.LIST_TYPE:
-        lastTypeNode.kind = node.kind;
-        lastTypeNode.type = { kind: node.type.kind };
-        lastTypeNode = lastTypeNode.type;
-        node = node.type;
-        continue;
-      case Kind.NON_NULL_TYPE:
-        lastTypeNode.kind = node.kind;
-        lastTypeNode.type = { kind: node.type.kind };
-        lastTypeNode = lastTypeNode.type;
-        node = node.type;
-        continue;
-      default:
-        throw federationUnexpectedNodeKindError(parentName, fieldName);
-    }
-  }
-  throw new Error(`Field ${parentName}.${fieldName} has more than 30 layers of nesting, or there is a cyclical error.`);
-}
-
 export type MutableDirectiveDefinitionNode = {
   arguments?: InputValueDefinitionNode[];
   description?: StringValueNode;
@@ -258,12 +231,12 @@ export function objectTypeDefinitionNodeToMutable(node: ObjectTypeDefinitionNode
 }
 
 export type MutableObjectTypeExtensionNode = {
-  description?: StringValueNode;
-  directives?: ConstDirectiveNode[];
   fields: FieldDefinitionNode[];
   interfaces: NamedTypeNode[];
   kind: Kind.OBJECT_TYPE_EXTENSION;
   name: NameNode;
+  description?: StringValueNode;
+  directives?: ConstDirectiveNode[];
 };
 
 export function objectTypeExtensionNodeToMutable(node: ObjectTypeExtensionNode): MutableObjectTypeExtensionNode {
@@ -307,14 +280,6 @@ export function scalarTypeDefinitionNodeToMutable(node: ScalarTypeDefinitionNode
   };
 }
 
-export type MutableTypeNode = {
-  kind: Kind.NAMED_TYPE | Kind.LIST_TYPE | Kind.NON_NULL_TYPE;
-  name?: NameNode;
-  type?: MutableTypeNode;
-};
-
-export const maximumTypeNesting = 30;
-
 export type MutableUnionTypeDefinitionNode = {
   description?: StringValueNode;
   directives?: ConstDirectiveNode[];

composition/src/ast/utils.ts

@@ -2,6 +2,8 @@ import {
   ArgumentNode,
   ConstDirectiveNode,
   DocumentNode,
+  EnumTypeDefinitionNode,
+  EnumTypeExtensionNode,
   FieldDefinitionNode,
   FieldNode,
   InputObjectTypeDefinitionNode,
@@ -15,10 +17,13 @@ import {
   ObjectTypeExtensionNode,
   OperationTypeNode,
   parse,
+  ScalarTypeDefinitionNode,
+  ScalarTypeExtensionNode,
   SchemaDefinitionNode,
   SchemaExtensionNode,
   SelectionSetNode,
   StringValueNode,
+  UnionTypeDefinitionNode,
   UnionTypeExtensionNode,
 } from 'graphql';
 import {
@@ -54,13 +59,6 @@ import {
   UNION_UPPER,
 } from '../utils/string-constants';
 import { duplicateInterfaceError, unexpectedKindFatalError } from '../errors/errors';
-import {
-  EnumTypeDefinitionNode,
-  EnumTypeExtensionNode,
-  ScalarTypeDefinitionNode,
-  ScalarTypeExtensionNode,
-  UnionTypeDefinitionNode,
-} from 'graphql/index';
 import { DirectiveContainer, EXECUTABLE_DIRECTIVE_LOCATIONS, NodeContainer } from '../federation/utils';
 
 export function isObjectLikeNodeEntity(node: ObjectLikeTypeNode): boolean {

composition/src/errors/errors.ts

@@ -134,7 +134,7 @@ export function duplicateInterfaceError(interfaceName: string, typeName: string)
   return new Error(`Interface "${interfaceName}" can only be defined on type "${typeName}" once.`);
 }
 
-export function duplicateUnionMemberError(memberName: string, typeName: string): Error {
+export function duplicateUnionMemberExtensionError(memberName: string, typeName: string): Error {
   return new Error(`Extension error:\n Member "${memberName}" already exists on union "${typeName}".`);
 }
 
@@ -163,8 +163,10 @@ export function noBaseTypeExtensionError(typeName: string): Error {
   return new Error(`Extension error:\n Could not extend the type "${typeName}" because no base definition exists.`);
 }
 
-export function noDefinedUnionMembersError(unionName: string): Error {
-  return new Error(`The union "${unionName}" must define at least one union member.`);
+export function noDefinedUnionMembersError(unionTypeName: string, extension = false): Error {
+  return new Error(
+    `The union ` + (extension ? 'extension' : '') + ` "${unionTypeName}" must define at least one union member.`,
+  );
 }
 
 export function operationDefinitionError(typeName: string, operationType: OperationTypeNode, actualType: Kind): Error {
@@ -211,10 +213,10 @@ export function shareableFieldDefinitionsError(parent: ObjectContainer, children
   );
 }
 
-export function undefinedDirectiveError(directiveName: string, hostPath: string): Error {
-  return new Error(
+export function undefinedDirectiveErrorMessage(directiveName: string, hostPath: string): string {
+  return (
     `The directive "${directiveName}" is declared on "${hostPath}",` +
-      ` but the directive is not defined in the schema.`,
+    ` but the directive is not defined in the schema.`
   );
 }
 
@@ -288,6 +290,10 @@ export function invalidUnionError(unionName: string): Error {
   return new Error(`Union "${unionName}" must have at least one member.`);
 }
 
+export function duplicateUnionMemberError(memberTypeName: string, unionTypeName: string): Error {
+  return new Error(`Member "${memberTypeName}" must only be defined on union "${unionTypeName}" once.`);
+}
+
 export const invalidDeprecatedDirectiveError = new Error(`
   Expected the @deprecated directive to have a single optional argument "reason" of the type "String!"
 `);
@@ -373,29 +379,6 @@ export function invalidKeyDirectiveArgumentErrorMessage(directiveKind: Kind): st
   return ` The required argument named "fields" must be type "String" and not type "${directiveKind}".`;
 }
 
-export function invalidGraphQLNameErrorMessage(type: string, name: string): string {
-  return (
-    ` The ${type} "${name}" is an invalid GraphQL name:\n` +
-    `  GraphQL names must match the following regex: /[_a-zA-Z][_a-zA-Z0-9]*/`
-  );
-}
-
-export const invalidOpeningBraceErrorMessage: string = ` Unexpected brace opening:\n  Received an opening brace "{" before the parent value was defined.`;
-
-export const invalidClosingBraceErrorMessage: string = ` Unexpected brace closure:\n  Received a closing brace "}" before any nested values were defined.`;
-
-export const invalidNestingClosureErrorMessage: string = ` Unexpected brace closure:\n  Received a closing brace "}" before its corresponding opening brace "{" was defined.`;
-
-export const invalidNestingErrorMessage: string = ` Invalid nesting:\n  A nested key was terminated without a closing brace "}".`;
-
-export function invalidEntityKeyError(parentTypeName: string, entityKey: string, errorMessage: string): Error {
-  return new Error(
-    `The directive "key" declared on the object "${parentTypeName}"` +
-      ` with the "fields" argument value of "${entityKey}" is invalid for the following reason:\n` +
-      errorMessage,
-  );
-}
-
 export function invalidKeyDirectivesError(parentTypeName: string, errorMessages: string[]): Error {
   return new Error(
     `The entity "${parentTypeName}" defines the following invalid "key" directive` +
@@ -438,7 +421,7 @@ export function unexpectedDirectiveLocationError(locationName: string): Error {
   return new Error(`Fatal: Unknown directive location "${locationName}".`);
 }
 
-export function unexpectedTypeNodeKindError(childPath: string): Error {
+export function unexpectedTypeNodeKindFatalError(childPath: string): Error {
   return new Error(
     `Fatal: Expected all constituent types of "${childPath}" to be one of the following: ` +
       `"LIST_TYPE", "NAMED_TYPE", or "NON_NULL_TYPE".`,
@@ -881,10 +864,8 @@ export function allFieldDefinitionsAreInaccessibleError(typeString: string, type
   );
 }
 
-export function equivalentSourceAndTargetOverrideError(subgraphName: string, hostPath: string): Error {
-  return new Error(
-    `Cannot override field "${hostPath}" because the source and target subgraph names are both "${subgraphName}"`,
-  );
+export function equivalentSourceAndTargetOverrideErrorMessage(subgraphName: string, hostPath: string): string {
+  return `Cannot override field "${hostPath}" because the source and target subgraph names are both "${subgraphName}"`;
 }
 
 export function undefinedEntityInterfaceImplementationsError(