Switch tests & internal funcs to accept ReadonlyArrays

src/__testUtils__/__tests__/genFuzzStrings-test.ts

@@ -4,7 +4,7 @@ import { describe, it } from 'mocha';
 import { genFuzzStrings } from '../genFuzzStrings';
 
 function expectFuzzStrings(options: {
-  allowedChars: Array<string>;
+  allowedChars: ReadonlyArray<string>;
   maxLength: number;
 }) {
   return expect([...genFuzzStrings(options)]);

src/__testUtils__/genFuzzStrings.ts

@@ -2,7 +2,7 @@
  * Generator that produces all possible combinations of allowed characters.
  */
 export function* genFuzzStrings(options: {
-  allowedChars: Array<string>;
+  allowedChars: ReadonlyArray<string>;
   maxLength: number;
 }): Generator<string, void, void> {
   const { allowedChars, maxLength } = options;

src/__tests__/starWarsData.ts

@@ -5,25 +5,25 @@
 export interface Character {
   id: string;
   name: string;
-  friends: Array<string>;
-  appearsIn: Array<number>;
+  friends: ReadonlyArray<string>;
+  appearsIn: ReadonlyArray<number>;
 }
 
 export interface Human {
   type: 'Human';
   id: string;
   name: string;
-  friends: Array<string>;
-  appearsIn: Array<number>;
+  friends: ReadonlyArray<string>;
+  appearsIn: ReadonlyArray<number>;
   homePlanet?: string;
 }
 
 export interface Droid {
   type: 'Droid';
   id: string;
   name: string;
-  friends: Array<string>;
-  appearsIn: Array<number>;
+  friends: ReadonlyArray<string>;
+  appearsIn: ReadonlyArray<number>;
   primaryFunction: string;
 }
 

src/execution/__tests__/lists-test.ts

@@ -37,7 +37,7 @@ describe('Execute: Accepts any iterable as list value', () => {
   });
 
   it('Accepts function arguments as a List value', () => {
-    function getArgs(..._args: Array<string>) {
+    function getArgs(..._args: ReadonlyArray<string>) {
       return arguments;
     }
     const listField = getArgs('one', 'two');

src/execution/__tests__/union-interface-test.ts

@@ -19,7 +19,7 @@ class Dog {
   barks: boolean;
   mother?: Dog;
   father?: Dog;
-  progeny: Array<Dog>;
+  progeny: ReadonlyArray<Dog>;
 
   constructor(name: string, barks: boolean) {
     this.name = name;
@@ -33,7 +33,7 @@ class Cat {
   meows: boolean;
   mother?: Cat;
   father?: Cat;
-  progeny: Array<Cat>;
+  progeny: ReadonlyArray<Cat>;
 
   constructor(name: string, meows: boolean) {
     this.name = name;
@@ -44,13 +44,13 @@ class Cat {
 
 class Person {
   name: string;
-  pets?: Array<Dog | Cat>;
-  friends?: Array<Dog | Cat | Person>;
+  pets?: ReadonlyArray<Dog | Cat>;
+  friends?: ReadonlyArray<Dog | Cat | Person>;
 
   constructor(
     name: string,
-    pets?: Array<Dog | Cat>,
-    friends?: Array<Dog | Cat | Person>,
+    pets?: ReadonlyArray<Dog | Cat>,
+    friends?: ReadonlyArray<Dog | Cat | Person>,
   ) {
     this.name = name;
     this.pets = pets;

src/execution/execute.ts

@@ -375,7 +375,7 @@ function executeFieldsSerially(
   parentType: GraphQLObjectType,
   sourceValue: unknown,
   path: Path | undefined,
-  fields: Map<string, Array<FieldNode>>,
+  fields: Map<string, ReadonlyArray<FieldNode>>,
 ): PromiseOrValue<ObjMap<unknown>> {
   return promiseReduce(
     fields.entries(),
@@ -413,7 +413,7 @@ function executeFields(
   parentType: GraphQLObjectType,
   sourceValue: unknown,
   path: Path | undefined,
-  fields: Map<string, Array<FieldNode>>,
+  fields: Map<string, ReadonlyArray<FieldNode>>,
 ): PromiseOrValue<ObjMap<unknown>> {
   const results = Object.create(null);
   let containsPromise = false;
@@ -463,7 +463,7 @@ export function collectFields(
   selectionSet: SelectionSetNode,
   fields: Map<string, Array<FieldNode>>,
   visitedFragmentNames: Set<string>,
-): Map<string, Array<FieldNode>> {
+): Map<string, ReadonlyArray<FieldNode>> {
   for (const selection of selectionSet.selections) {
     switch (selection.kind) {
       case Kind.FIELD: {
@@ -1075,7 +1075,7 @@ function _collectSubfields(
   exeContext: ExecutionContext,
   returnType: GraphQLObjectType,
   fieldNodes: ReadonlyArray<FieldNode>,
-): Map<string, Array<FieldNode>> {
+): Map<string, ReadonlyArray<FieldNode>> {
   let subFieldNodes = new Map();
   const visitedFragmentNames = new Set<string>();
   for (const node of fieldNodes) {

src/jsutils/__tests__/suggestionList-test.ts

@@ -3,7 +3,7 @@ import { describe, it } from 'mocha';
 
 import { suggestionList } from '../suggestionList';
 
-function expectSuggestions(input: string, options: Array<string>) {
+function expectSuggestions(input: string, options: ReadonlyArray<string>) {
   return expect(suggestionList(input, options));
 }
 

src/jsutils/inspect.ts

@@ -8,7 +8,10 @@ export function inspect(value: unknown): string {
   return formatValue(value, []);
 }
 
-function formatValue(value: unknown, seenValues: Array<unknown>): string {
+function formatValue(
+  value: unknown,
+  seenValues: ReadonlyArray<unknown>,
+): string {
   switch (typeof value) {
     case 'string':
       return JSON.stringify(value);
@@ -23,7 +26,7 @@ function formatValue(value: unknown, seenValues: Array<unknown>): string {
 
 function formatObjectValue(
   value: object | null,
-  previouslySeenValues: Array<unknown>,
+  previouslySeenValues: ReadonlyArray<unknown>,
 ): string {
   if (value === null) {
     return 'null';
@@ -55,7 +58,10 @@ function isJSONable(value: any): value is { toJSON: () => unknown } {
   return typeof value.toJSON === 'function';
 }
 
-function formatObject(object: object, seenValues: Array<unknown>): string {
+function formatObject(
+  object: object,
+  seenValues: ReadonlyArray<unknown>,
+): string {
   const entries = Object.entries(object);
   if (entries.length === 0) {
     return '{}';
@@ -72,8 +78,8 @@ function formatObject(object: object, seenValues: Array<unknown>): string {
 }
 
 function formatArray(
-  array: Array<unknown>,
-  seenValues: Array<unknown>,
+  array: ReadonlyArray<unknown>,
+  seenValues: ReadonlyArray<unknown>,
 ): string {
   if (array.length === 0) {
     return '[]';

src/language/__tests__/blockString-test.ts

@@ -7,7 +7,7 @@ import {
   printBlockString,
 } from '../blockString';
 
-function joinLines(...args: Array<string>) {
+function joinLines(...args: ReadonlyArray<string>) {
   return args.join('\n');
 }
 

src/type/__tests__/validation-test.ts

@@ -79,7 +79,7 @@ function withModifiers<T extends GraphQLNamedType>(
   ];
 }
 
-const outputTypes: Array<GraphQLOutputType> = [
+const outputTypes: ReadonlyArray<GraphQLOutputType> = [
   ...withModifiers(GraphQLString),
   ...withModifiers(SomeScalarType),
   ...withModifiers(SomeEnumType),
@@ -88,18 +88,18 @@ const outputTypes: Array<GraphQLOutputType> = [
   ...withModifiers(SomeInterfaceType),
 ];
 
-const notOutputTypes: Array<GraphQLInputType> = [
+const notOutputTypes: ReadonlyArray<GraphQLInputType> = [
   ...withModifiers(SomeInputObjectType),
 ];
 
-const inputTypes: Array<GraphQLInputType> = [
+const inputTypes: ReadonlyArray<GraphQLInputType> = [
   ...withModifiers(GraphQLString),
   ...withModifiers(SomeScalarType),
   ...withModifiers(SomeEnumType),
   ...withModifiers(SomeInputObjectType),
 ];
 
-const notInputTypes: Array<GraphQLOutputType> = [
+const notInputTypes: ReadonlyArray<GraphQLOutputType> = [
   ...withModifiers(SomeObjectType),
   ...withModifiers(SomeUnionType),
   ...withModifiers(SomeInterfaceType),

src/utilities/findBreakingChanges.ts

@@ -557,9 +557,9 @@ function diff<T extends { name: string }>(
   oldArray: ReadonlyArray<T>,
   newArray: ReadonlyArray<T>,
 ): {
-  added: Array<T>;
-  removed: Array<T>;
-  persisted: Array<[T, T]>;
+  added: ReadonlyArray<T>;
+  removed: ReadonlyArray<T>;
+  persisted: ReadonlyArray<[T, T]>;
 } {
   const added: Array<T> = [];
   const removed: Array<T> = [];

src/utilities/separateOperations.ts

@@ -63,7 +63,7 @@ export function separateOperations(
   return separatedDocumentASTs;
 }
 
-type DepGraph = ObjMap<Array<string>>;
+type DepGraph = ObjMap<ReadonlyArray<string>>;
 
 // From a dependency graph, collects a list of transitive dependencies by
 // recursing through a dependency graph.