Preset Unknown types errors as GraphQLError (#68)

Previously, some logic paths were throwing an exception

.changeset/sour-adults-sit.md

@@ -0,0 +1,6 @@
+---
+'@theguild/federation-composition': patch
+---
+
+Unknown types are now always reported as GraphQLError (previously in some logic paths, it was an
+exception).

__tests__/subgraph/key-fields.spec.ts

@@ -187,4 +187,37 @@ testVersions((api, version) => {
  ]),
  );
  });
+
+ test('missing _FieldSet definition', () => {
+ expect(
+ api.composeServices([
+ {
+ name: 'foo',
+ typeDefs: graphql`
+ directive @key(fields: _FieldSet!) repeatable on OBJECT | INTERFACE
+
+ type Query {
+ users: [User]
+ }
+
+ type User @key(fields: "id") {
+ id: ID!
+ name: String!
+ }
+ `,
+ },
+ ]),
+ ).toEqual(
+ expect.objectContaining({
+ errors: expect.arrayContaining([
+ expect.objectContaining({
+ message: expect.stringContaining(`[foo] Unknown type _FieldSet`),
+ extensions: expect.objectContaining({
+ code: 'INVALID_GRAPHQL',
+ }),
+ }),
+ ]),
+ }),
+ );
+ });
 });

src/subgraph/validation/validate-state.ts

@@ -34,6 +34,8 @@ const specifiedScalars = new Set(specifiedScalarTypes.map(t => t.name));
 
 type ReportErrorFn = (message: string) => void;
 
+const SKIP = Symbol('skip');
+
 export function validateSubgraphState(state: SubgraphState, context: SubgraphValidationContext) {
  const errors: GraphQLError[] = [];
 
@@ -130,7 +132,13 @@ function validateDirectives(
  continue;
  }
 
- if (!isInputType(state, argInputTypeName)) {
+ const isInput = isInputType(state, argInputTypeName);
+
+ if (isInput === SKIP) {
+ continue;
+ }
+
+ if (!isInput) {
  reportError(
  `The type of @${directive.name}(${arg.name}:) must be Input Type ` +
  `but got: ${arg.type}.`,
@@ -255,7 +263,13 @@ function validateFields(
  }
 
  // Ensure the type is an output type
- if (!isOutputType(state, fieldTypeName)) {
+ const isOutput = isOutputType(state, fieldTypeName);
+
+ if (isOutput === SKIP) {
+ continue;
+ }
+
+ if (!isOutput) {
  reportError(
  `The type of "${type.name}.${field.name}" must be Output Type but got: "${field.type}".`,
  );
@@ -278,7 +292,13 @@ function validateFields(
  }
 
  // Ensure the type is an input type
- if (!isInputType(state, argTypeName)) {
+ const isInput = isInputType(state, argTypeName);
+
+ if (isInput === SKIP) {
+ continue;
+ }
+
+ if (!isInput) {
  const isList = arg.type.endsWith(']');
  const isNonNull = arg.type.endsWith('!');
  const extra = isList ? ', a ListType' : isNonNull ? ', a NonNullType' : '';
@@ -459,7 +479,13 @@ function validateInputFields(
  }
 
  // Ensure the type is an input type
- if (!isInputType(state, fieldTypeName)) {
+ const isInput = isInputType(state, fieldTypeName);
+
+ if (isInput === SKIP) {
+ continue;
+ }
+
+ if (!isInput) {
  const isList = field.type.endsWith(']');
  const isNonNull = field.type.endsWith('!');
  const extra = isList ? ', a ListType' : isNonNull ? ', a NonNullType' : '';
@@ -766,7 +792,7 @@ function isRequiredInputField(arg: InputField): boolean {
  return isNonNull(arg.type) && arg.defaultValue === undefined;
 }
 
-function isOutputType(state: SubgraphState, typeName: string): boolean {
+function isOutputType(state: SubgraphState, typeName: string) {
  const type = state.types.get(typeName);
 
  if (!type) {
@@ -776,15 +802,16 @@ function isOutputType(state: SubgraphState, typeName: string): boolean {
 
  // The existence of the type was already validated.
  // See: KnownTypeNamesRule
- throw new Error(`Expected to find ${typeName} type`);
+ // No need to throw an exception here, because it affects the rest of the validation logic.
+ return SKIP;
  }
 
  // Only input types are not output types (scalars and enums are in both).
  // This is a quick check, to make it least expensive possible.
  return !isInputObjectType(type);
 }
 
-export function isInputType(state: SubgraphState, typeName: string): boolean {
+export function isInputType(state: SubgraphState, typeName: string) {
  const type = state.types.get(typeName);
 
  if (!type) {
@@ -794,7 +821,8 @@ export function isInputType(state: SubgraphState, typeName: string): boolean {
 
  // The existence of the type was already validated.
  // See: KnownTypeNamesRule
- throw new Error(`Expected to find ${typeName} type`);
+ // No need to throw an exception here, because it affects the rest of the validation logic.
+ return SKIP;
  }
 
  return isScalarType(type) || isEnumType(type) || isInputObjectType(type);