chore: bump React Native to 0.64 RC (#626)

* chore: bump React Native to 0.64 RC

* Snapshot update

* Bumped node version to 12 on CI

* Removed removed supress_comment syntax from config

* codemod types-first

* Prettied files after codemod

* Added flow types to API returns

* don't return null from fireEvent handlers

* return ReactTestInstance instead of any

* fix render returning any

* less anys

* less anys

* simplify call type

* simplify

* add Flow to missing files, type debug better

Co-authored-by: Michał Parkitny <michal.parkitny@callstack.com>
Co-authored-by: Michał Pierzchała <thymikee@gmail.com>

src/__tests__/__snapshots__/render.test.js.snap

@@ -134,7 +134,7 @@ exports[`debug: shallow 1`] = `
   >
     not fresh
   </Text>
-  <Component
+  <TextInput
     allowFontScaling={true}
     placeholder=\\"Add custom freshness\\"
     rejectResponderTermination={true}
@@ -142,7 +142,7 @@ exports[`debug: shallow 1`] = `
     underlineColorAndroid=\\"transparent\\"
     value=\\"Custom Freshie\\"
   />
-  <Component
+  <TextInput
     allowFontScaling={true}
     placeholder=\\"Who inspected freshness?\\"
     rejectResponderTermination={true}
@@ -184,7 +184,7 @@ exports[`debug: shallow with message 1`] = `
   >
     not fresh
   </Text>
-  <Component
+  <TextInput
     allowFontScaling={true}
     placeholder=\\"Add custom freshness\\"
     rejectResponderTermination={true}
@@ -192,7 +192,7 @@ exports[`debug: shallow with message 1`] = `
     underlineColorAndroid=\\"transparent\\"
     value=\\"Custom Freshie\\"
   />
-  <Component
+  <TextInput
     allowFontScaling={true}
     placeholder=\\"Who inspected freshness?\\"
     rejectResponderTermination={true}

src/__tests__/auto-cleanup-skip.test.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { View } from 'react-native';
 

src/__tests__/auto-cleanup.test.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { View } from 'react-native';
 import { render } from '..';

src/act.js

@@ -1,8 +1,9 @@
 // @flow
 import { act } from 'react-test-renderer';
+import type { Thenable } from './types.flow';
 
 const actMock = (callback: () => void) => {
   callback();
 };
 
-export default act || actMock;
+export default (act || actMock: (callback: () => void) => Thenable);

src/fireEvent.js

@@ -89,7 +89,7 @@ const invokeEvent = (
   const handler = findEventHandler(element, eventName, callsite);
 
   if (!handler) {
-    return null;
+    return;
   }
 
   let returnValue;
@@ -104,18 +104,20 @@ const invokeEvent = (
 const toEventHandlerName = (eventName: string) =>
   `on${eventName.charAt(0).toUpperCase()}${eventName.slice(1)}`;
 
-const pressHandler = (element: ReactTestInstance) =>
+const pressHandler = (element: ReactTestInstance): void =>
   invokeEvent(element, 'press', pressHandler);
-const changeTextHandler = (element: ReactTestInstance, ...data: Array<any>) =>
-  invokeEvent(element, 'changeText', changeTextHandler, ...data);
-const scrollHandler = (element: ReactTestInstance, ...data: Array<any>) =>
+const changeTextHandler = (
+  element: ReactTestInstance,
+  ...data: Array<any>
+): void => invokeEvent(element, 'changeText', changeTextHandler, ...data);
+const scrollHandler = (element: ReactTestInstance, ...data: Array<any>): void =>
   invokeEvent(element, 'scroll', scrollHandler, ...data);
 
 const fireEvent = (
   element: ReactTestInstance,
   eventName: string,
   ...data: Array<any>
-) => invokeEvent(element, eventName, fireEvent, ...data);
+): void => invokeEvent(element, eventName, fireEvent, ...data);
 
 fireEvent.press = pressHandler;
 fireEvent.changeText = changeTextHandler;

src/helpers/a11yAPI.js

@@ -6,11 +6,11 @@ import makeQuery from './makeQuery';
 type GetReturn = ReactTestInstance;
 type GetAllReturn = Array<ReactTestInstance>;
 type QueryReturn = ReactTestInstance | null;
-type QueryAllReturn = Array<ReactTestInstance> | [];
+type QueryAllReturn = Array<ReactTestInstance>;
 type FindReturn = Promise<GetReturn>;
 type FindAllReturn = Promise<GetAllReturn>;
 
-type A11yAPI = {|
+export type A11yAPI = {|
   // Label
   getByA11yLabel: (string | RegExp) => GetReturn,
   getByLabelText: (string | RegExp) => GetReturn,
@@ -116,7 +116,7 @@ export function matchObject<T: {}>(prop?: T, matcher: T): boolean {
     : false;
 }
 
-const a11yAPI = (instance: ReactTestInstance): A11yAPI =>
+export const a11yAPI = (instance: ReactTestInstance): A11yAPI =>
   ({
     ...makeQuery(
       'accessibilityLabel',
@@ -239,5 +239,3 @@ const a11yAPI = (instance: ReactTestInstance): A11yAPI =>
       matchObject
     )(instance),
   }: any);
-
-export default a11yAPI;

src/helpers/debugDeep.js

@@ -6,7 +6,7 @@ import format from './format';
  */
 export default function debugDeep(
   instance: ?ReactTestRendererJSON,
-  message?: any = ''
+  message?: string
 ) {
   if (message) {
     console.log(`${message}\n\n`, format(instance));

src/helpers/debugShallow.js

@@ -8,7 +8,7 @@ import format from './format';
  */
 export default function debugShallow(
   instance: ReactTestInstance | React.Element<any>,
-  message?: any
+  message?: string
 ) {
   const { output } = shallowInternal(instance);
 

src/helpers/errors.js

@@ -10,7 +10,7 @@ export class ErrorWithStack extends Error {
   }
 }
 
-export const createLibraryNotSupportedError = (error: Error) =>
+export const createLibraryNotSupportedError = (error: Error): Error =>
   new Error(
     `Currently the only supported library to search by text is "react-native".\n\n${error.message}`
   );
@@ -19,7 +19,7 @@ export const prepareErrorMessage = (
   error: Error,
   name: ?string,
   value: ?mixed
-) => {
+): string => {
   // Strip info about custom predicate
   let errorMessage = error.message.replace(
     / matching custom predicate[^]*/gm,
@@ -32,7 +32,7 @@ export const prepareErrorMessage = (
   return errorMessage;
 };
 
-export const createQueryByError = (error: Error, callsite: Function) => {
+export const createQueryByError = (error: Error, callsite: Function): null => {
   if (error.message.includes('No instances found')) {
     return null;
   }

src/helpers/findByAPI.js

@@ -13,6 +13,43 @@ import {
 } from './getByAPI';
 import { throwRenamedFunctionError } from './errors';
 
+export type FindByAPI = {|
+  findAllByDisplayValue: (
+    value: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<Array<ReactTestInstance>>,
+  findAllByPlaceholder: () => void,
+  findAllByPlaceholderText: (
+    placeholder: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<Array<ReactTestInstance>>,
+  findAllByTestId: (
+    testId: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<Array<ReactTestInstance>>,
+  findAllByText: (
+    text: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<Array<ReactTestInstance>>,
+  findByDisplayValue: (
+    value: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<ReactTestInstance>,
+  findByPlaceholder: () => void,
+  findByPlaceholderText: (
+    placeholder: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<ReactTestInstance>,
+  findByTestId: (
+    testId: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<ReactTestInstance>,
+  findByText: (
+    text: string | RegExp,
+    waitForOptions?: WaitForOptions
+  ) => Promise<ReactTestInstance>,
+|};
+
 const makeFindQuery = <Text, Result>(
   instance: ReactTestInstance,
   getQuery: (instance: ReactTestInstance) => (text: Text) => Result,
@@ -20,48 +57,88 @@ const makeFindQuery = <Text, Result>(
   waitForOptions: WaitForOptions
 ): Promise<Result> => waitFor(() => getQuery(instance)(text), waitForOptions);
 
-export const findByTestId = (instance: ReactTestInstance) => (
+export const findByTestId = (
+  instance: ReactTestInstance
+): ((
+  testId: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<ReactTestInstance>) => (
   testId: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getByTestId, testId, waitForOptions);
 
-export const findAllByTestId = (instance: ReactTestInstance) => (
+export const findAllByTestId = (
+  instance: ReactTestInstance
+): ((
+  testId: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<Array<ReactTestInstance>>) => (
   testId: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getAllByTestId, testId, waitForOptions);
 
-export const findByText = (instance: ReactTestInstance) => (
+export const findByText = (
+  instance: ReactTestInstance
+): ((
+  text: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<ReactTestInstance>) => (
   text: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getByText, text, waitForOptions);
 
-export const findAllByText = (instance: ReactTestInstance) => (
+export const findAllByText = (
+  instance: ReactTestInstance
+): ((
+  text: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<Array<ReactTestInstance>>) => (
   text: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getAllByText, text, waitForOptions);
 
-export const findByPlaceholderText = (instance: ReactTestInstance) => (
+export const findByPlaceholderText = (
+  instance: ReactTestInstance
+): ((
+  placeholder: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<ReactTestInstance>) => (
   placeholder: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getByPlaceholderText, placeholder, waitForOptions);
 
-export const findAllByPlaceholderText = (instance: ReactTestInstance) => (
+export const findAllByPlaceholderText = (
+  instance: ReactTestInstance
+): ((
+  placeholder: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<Array<ReactTestInstance>>) => (
   placeholder: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) =>
   makeFindQuery(instance, getAllByPlaceholderText, placeholder, waitForOptions);
 
-export const findByDisplayValue = (instance: ReactTestInstance) => (
+export const findByDisplayValue = (
+  instance: ReactTestInstance
+): ((
+  value: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<ReactTestInstance>) => (
   value: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getByDisplayValue, value, waitForOptions);
 
-export const findAllByDisplayValue = (instance: ReactTestInstance) => (
+export const findAllByDisplayValue = (
+  instance: ReactTestInstance
+): ((
+  value: string | RegExp,
+  waitForOptions?: WaitForOptions
+) => Promise<Array<ReactTestInstance>>) => (
   value: string | RegExp,
   waitForOptions: WaitForOptions = {}
 ) => makeFindQuery(instance, getAllByDisplayValue, value, waitForOptions);
 
-export const findByAPI = (instance: ReactTestInstance) => ({
+export const findByAPI = (instance: ReactTestInstance): FindByAPI => ({
   findByTestId: findByTestId(instance),
   findByText: findByText(instance),
   findByPlaceholderText: findByPlaceholderText(instance),

src/helpers/format.js

@@ -1,7 +1,7 @@
 // @flow
 import prettyFormat, { plugins } from 'pretty-format';
 
-const format = (input: ?ReactTestRendererJSON) =>
+const format = (input: ?ReactTestRendererJSON): typeof prettyFormat =>
   prettyFormat(input, {
     plugins: [plugins.ReactTestComponent, plugins.ReactElement],
     highlight: true,

src/helpers/getByAPI.js

@@ -9,6 +9,37 @@ import {
   throwRenamedFunctionError,
 } from './errors';
 
+export type GetByAPI = {|
+  getByText: (text: string | RegExp) => ReactTestInstance,
+  getByPlaceholderText: (placeholder: string | RegExp) => ReactTestInstance,
+  getByDisplayValue: (value: string | RegExp) => ReactTestInstance,
+  getByTestId: (testID: string | RegExp) => ReactTestInstance,
+  getAllByTestId: (testID: string | RegExp) => Array<ReactTestInstance>,
+  getAllByText: (text: string | RegExp) => Array<ReactTestInstance>,
+  getAllByPlaceholderText: (
+    placeholder: string | RegExp
+  ) => Array<ReactTestInstance>,
+  getAllByDisplayValue: (value: string | RegExp) => Array<ReactTestInstance>,
+
+  // Unsafe aliases
+  UNSAFE_getByType: <P>(type: React.ComponentType<P>) => ReactTestInstance,
+  UNSAFE_getAllByType: <P>(
+    type: React.ComponentType<P>
+  ) => Array<ReactTestInstance>,
+  UNSAFE_getByProps: (props: { [string]: any }) => ReactTestInstance,
+  UNSAFE_getAllByProps: (props: { [string]: any }) => Array<ReactTestInstance>,
+
+  getByName: () => void,
+  getByType: () => void,
+  getByProps: () => void,
+  getAllByName: () => void,
+  getAllByType: () => void,
+  getAllByProps: () => void,
+
+  getByPlaceholder: () => void,
+  getAllByPlaceholder: () => void,
+|};
+
 const filterNodeByType = (node, type) => node.type === type;
 
 const getNodeByText = (node, text) => {
@@ -92,7 +123,9 @@ const getNodeByTestId = (node, testID) => {
     : testID.test(node.props.testID);
 };
 
-export const getByText = (instance: ReactTestInstance) =>
+export const getByText = (
+  instance: ReactTestInstance
+): ((text: string | RegExp) => ReactTestInstance) =>
   function getByTextFn(text: string | RegExp) {
     try {
       return instance.find((node) => getNodeByText(node, text));
@@ -104,7 +137,9 @@ export const getByText = (instance: ReactTestInstance) =>
     }
   };
 
-export const getByPlaceholderText = (instance: ReactTestInstance) =>
+export const getByPlaceholderText = (
+  instance: ReactTestInstance
+): ((placeholder: string | RegExp) => ReactTestInstance) =>
   function getByPlaceholderTextFn(placeholder: string | RegExp) {
     try {
       return instance.find((node) =>
@@ -118,7 +153,9 @@ export const getByPlaceholderText = (instance: ReactTestInstance) =>
     }
   };
 
-export const getByDisplayValue = (instance: ReactTestInstance) =>
+export const getByDisplayValue = (
+  instance: ReactTestInstance
+): ((displayValue: string | RegExp) => ReactTestInstance) =>
   function getByDisplayValueFn(displayValue: string | RegExp) {
     try {
       return instance.find((node) =>
@@ -132,7 +169,9 @@ export const getByDisplayValue = (instance: ReactTestInstance) =>
     }
   };
 
-export const getByTestId = (instance: ReactTestInstance) =>
+export const getByTestId = (
+  instance: ReactTestInstance
+): ((testID: string | RegExp) => ReactTestInstance) =>
   function getByTestIdFn(testID: string | RegExp) {
     try {
       const results = getAllByTestId(instance)(testID);
@@ -151,7 +190,9 @@ export const getByTestId = (instance: ReactTestInstance) =>
     }
   };
 
-export const getAllByText = (instance: ReactTestInstance) =>
+export const getAllByText = (
+  instance: ReactTestInstance
+): ((text: string | RegExp) => Array<ReactTestInstance>) =>
   function getAllByTextFn(text: string | RegExp) {
     const results = instance.findAll((node) => getNodeByText(node, text));
     if (results.length === 0) {
@@ -163,7 +204,9 @@ export const getAllByText = (instance: ReactTestInstance) =>
     return results;
   };
 
-export const getAllByPlaceholderText = (instance: ReactTestInstance) =>
+export const getAllByPlaceholderText = (
+  instance: ReactTestInstance
+): ((placeholder: string | RegExp) => Array<ReactTestInstance>) =>
   function getAllByPlaceholderTextFn(placeholder: string | RegExp) {
     const results = instance.findAll((node) =>
       getTextInputNodeByPlaceholderText(node, placeholder)
@@ -177,7 +220,9 @@ export const getAllByPlaceholderText = (instance: ReactTestInstance) =>
     return results;
   };
 
-export const getAllByDisplayValue = (instance: ReactTestInstance) =>
+export const getAllByDisplayValue = (
+  instance: ReactTestInstance
+): ((value: string | RegExp) => Array<ReactTestInstance>) =>
   function getAllByDisplayValueFn(value: string | RegExp) {
     const results = instance.findAll((node) =>
       getTextInputNodeByDisplayValue(node, value)
@@ -191,7 +236,9 @@ export const getAllByDisplayValue = (instance: ReactTestInstance) =>
     return results;
   };
 
-export const getAllByTestId = (instance: ReactTestInstance) =>
+export const getAllByTestId = (
+  instance: ReactTestInstance
+): ((testID: string | RegExp) => Array<ReactTestInstance>) =>
   function getAllByTestIdFn(testID: string | RegExp): ReactTestInstance[] {
     const results = instance
       .findAll((node) => getNodeByTestId(node, testID))
@@ -206,7 +253,9 @@ export const getAllByTestId = (instance: ReactTestInstance) =>
     return results;
   };
 
-export const UNSAFE_getByType = (instance: ReactTestInstance) =>
+export const UNSAFE_getByType = (
+  instance: ReactTestInstance
+): ((type: React.ComponentType<any>) => ReactTestInstance) =>
   function getByTypeFn(type: React.ComponentType<any>) {
     try {
       return instance.findByType(type);
@@ -215,7 +264,9 @@ export const UNSAFE_getByType = (instance: ReactTestInstance) =>
     }
   };
 
-export const UNSAFE_getByProps = (instance: ReactTestInstance) =>
+export const UNSAFE_getByProps = (
+  instance: ReactTestInstance
+): ((props: { [propName: string]: any }) => ReactTestInstance) =>
   function getByPropsFn(props: { [propName: string]: any }) {
     try {
       return instance.findByProps(props);
@@ -224,7 +275,9 @@ export const UNSAFE_getByProps = (instance: ReactTestInstance) =>
     }
   };
 
-export const UNSAFE_getAllByType = (instance: ReactTestInstance) =>
+export const UNSAFE_getAllByType = (
+  instance: ReactTestInstance
+): ((type: React.ComponentType<any>) => Array<ReactTestInstance>) =>
   function getAllByTypeFn(type: React.ComponentType<any>) {
     const results = instance.findAllByType(type);
     if (results.length === 0) {
@@ -233,7 +286,9 @@ export const UNSAFE_getAllByType = (instance: ReactTestInstance) =>
     return results;
   };
 
-export const UNSAFE_getAllByProps = (instance: ReactTestInstance) =>
+export const UNSAFE_getAllByProps = (
+  instance: ReactTestInstance
+): ((props: { [propName: string]: any }) => Array<ReactTestInstance>) =>
   function getAllByPropsFn(props: { [propName: string]: any }) {
     const results = instance.findAllByProps(props);
     if (results.length === 0) {
@@ -245,7 +300,7 @@ export const UNSAFE_getAllByProps = (instance: ReactTestInstance) =>
     return results;
   };
 
-export const getByAPI = (instance: ReactTestInstance) => ({
+export const getByAPI = (instance: ReactTestInstance): GetByAPI => ({
   getByText: getByText(instance),
   getByPlaceholderText: getByPlaceholderText(instance),
   getByDisplayValue: getByDisplayValue(instance),

src/helpers/makeQuery.js

@@ -30,7 +30,9 @@ const makeQuery = <P: mixed, M: mixed>(
   name: string,
   queryNames: QueryNames,
   matcherFn: (prop: P, value: M) => boolean
-) => (instance: ReactTestInstance) => {
+): ((instance: ReactTestInstance) => { ... }) => (
+  instance: ReactTestInstance
+) => {
   const getBy = (matcher: M) => {
     try {
       return instance.find(

src/helpers/queryByAPI.js

@@ -20,7 +20,45 @@ import {
   throwRenamedFunctionError,
 } from './errors';
 
-export const queryByText = (instance: ReactTestInstance) =>
+export type QueryByAPI = {|
+  queryByText: (name: string | RegExp) => ReactTestInstance | null,
+  queryByPlaceholderText: (
+    placeholder: string | RegExp
+  ) => ReactTestInstance | null,
+  queryByDisplayValue: (value: string | RegExp) => ReactTestInstance | null,
+  queryByTestId: (testID: string | RegExp) => ReactTestInstance | null,
+  queryAllByTestId: (testID: string | RegExp) => Array<ReactTestInstance>,
+  queryAllByText: (text: string | RegExp) => Array<ReactTestInstance>,
+  queryAllByPlaceholderText: (
+    placeholder: string | RegExp
+  ) => Array<ReactTestInstance>,
+  queryAllByDisplayValue: (value: string | RegExp) => Array<ReactTestInstance>,
+
+  // Unsafe aliases
+  UNSAFE_queryByType: <P>(
+    type: React.ComponentType<P>
+  ) => ReactTestInstance | null,
+  UNSAFE_queryAllByType: <P>(
+    type: React.ComponentType<P>
+  ) => Array<ReactTestInstance>,
+  UNSAFE_queryByProps: (props: { [string]: any }) => ReactTestInstance | null,
+  UNSAFE_queryAllByProps: (props: {
+    [string]: any,
+  }) => Array<ReactTestInstance>,
+  queryByName: () => void,
+  queryByType: () => void,
+  queryByProps: () => void,
+  queryAllByName: () => void,
+  queryAllByType: () => void,
+  queryAllByProps: () => void,
+
+  queryByPlaceholder: () => void,
+  queryAllByPlaceholder: () => void,
+|};
+
+export const queryByText = (
+  instance: ReactTestInstance
+): ((text: string | RegExp) => ReactTestInstance | null) =>
   function queryByTextFn(text: string | RegExp) {
     try {
       return getByText(instance)(text);
@@ -29,7 +67,9 @@ export const queryByText = (instance: ReactTestInstance) =>
     }
   };
 
-export const queryByPlaceholderText = (instance: ReactTestInstance) =>
+export const queryByPlaceholderText = (
+  instance: ReactTestInstance
+): ((placeholder: string | RegExp) => ReactTestInstance | null) =>
   function queryByPlaceholderTextFn(placeholder: string | RegExp) {
     try {
       return getByPlaceholderText(instance)(placeholder);
@@ -38,7 +78,9 @@ export const queryByPlaceholderText = (instance: ReactTestInstance) =>
     }
   };
 
-export const queryByDisplayValue = (instance: ReactTestInstance) =>
+export const queryByDisplayValue = (
+  instance: ReactTestInstance
+): ((value: string | RegExp) => ReactTestInstance | null) =>
   function queryByDisplayValueFn(value: string | RegExp) {
     try {
       return getByDisplayValue(instance)(value);
@@ -47,7 +89,9 @@ export const queryByDisplayValue = (instance: ReactTestInstance) =>
     }
   };
 
-export const queryByTestId = (instance: ReactTestInstance) =>
+export const queryByTestId = (
+  instance: ReactTestInstance
+): ((testID: string | RegExp) => ReactTestInstance | null) =>
   function queryByTestIdFn(testID: string | RegExp) {
     try {
       return getByTestId(instance)(testID);
@@ -56,7 +100,9 @@ export const queryByTestId = (instance: ReactTestInstance) =>
     }
   };
 
-export const queryAllByText = (instance: ReactTestInstance) => (
+export const queryAllByText = (
+  instance: ReactTestInstance
+): ((text: string | RegExp) => Array<ReactTestInstance>) => (
   text: string | RegExp
 ) => {
   try {
@@ -66,7 +112,9 @@ export const queryAllByText = (instance: ReactTestInstance) => (
   }
 };
 
-export const queryAllByPlaceholderText = (instance: ReactTestInstance) => (
+export const queryAllByPlaceholderText = (
+  instance: ReactTestInstance
+): ((placeholder: string | RegExp) => Array<ReactTestInstance>) => (
   placeholder: string | RegExp
 ) => {
   try {
@@ -76,7 +124,9 @@ export const queryAllByPlaceholderText = (instance: ReactTestInstance) => (
   }
 };
 
-export const queryAllByDisplayValue = (instance: ReactTestInstance) => (
+export const queryAllByDisplayValue = (
+  instance: ReactTestInstance
+): ((value: string | RegExp) => Array<ReactTestInstance>) => (
   value: string | RegExp
 ) => {
   try {
@@ -86,7 +136,9 @@ export const queryAllByDisplayValue = (instance: ReactTestInstance) => (
   }
 };
 
-export const queryAllByTestId = (instance: ReactTestInstance) => (
+export const queryAllByTestId = (
+  instance: ReactTestInstance
+): ((testID: string | RegExp) => Array<ReactTestInstance>) => (
   testID: string | RegExp
 ) => {
   try {
@@ -96,7 +148,9 @@ export const queryAllByTestId = (instance: ReactTestInstance) => (
   }
 };
 
-export const UNSAFE_queryByType = (instance: ReactTestInstance) =>
+export const UNSAFE_queryByType = (
+  instance: ReactTestInstance
+): ((type: React.ComponentType<any>) => ReactTestInstance | null) =>
   function queryByTypeFn(type: React.ComponentType<any>) {
     try {
       return UNSAFE_getByType(instance)(type);
@@ -105,7 +159,9 @@ export const UNSAFE_queryByType = (instance: ReactTestInstance) =>
     }
   };
 
-export const UNSAFE_queryByProps = (instance: ReactTestInstance) =>
+export const UNSAFE_queryByProps = (
+  instance: ReactTestInstance
+): ((props: { [propName: string]: any }) => ReactTestInstance | null) =>
   function queryByPropsFn(props: { [propName: string]: any }) {
     try {
       return UNSAFE_getByProps(instance)(props);
@@ -114,7 +170,9 @@ export const UNSAFE_queryByProps = (instance: ReactTestInstance) =>
     }
   };
 
-export const UNSAFE_queryAllByType = (instance: ReactTestInstance) => (
+export const UNSAFE_queryAllByType = (
+  instance: ReactTestInstance
+): ((type: React.ComponentType<any>) => Array<ReactTestInstance>) => (
   type: React.ComponentType<any>
 ) => {
   try {
@@ -124,9 +182,11 @@ export const UNSAFE_queryAllByType = (instance: ReactTestInstance) => (
   }
 };
 
-export const UNSAFE_queryAllByProps = (instance: ReactTestInstance) => (props: {
+export const UNSAFE_queryAllByProps = (
+  instance: ReactTestInstance
+): ((props: {
   [propName: string]: any,
-}) => {
+}) => Array<ReactTestInstance>) => (props: { [propName: string]: any }) => {
   try {
     return UNSAFE_getAllByProps(instance)(props);
   } catch (error) {
@@ -134,7 +194,7 @@ export const UNSAFE_queryAllByProps = (instance: ReactTestInstance) => (props: {
   }
 };
 
-export const queryByAPI = (instance: ReactTestInstance) => ({
+export const queryByAPI = (instance: ReactTestInstance): QueryByAPI => ({
   queryByTestId: queryByTestId(instance),
   queryByText: queryByText(instance),
   queryByPlaceholderText: queryByPlaceholderText(instance),

src/render.js

@@ -3,10 +3,10 @@ import * as React from 'react';
 import TestRenderer, { type ReactTestRenderer } from 'react-test-renderer'; // eslint-disable-line import/no-extraneous-dependencies
 import act from './act';
 import { addToCleanupQueue } from './cleanup';
-import { getByAPI } from './helpers/getByAPI';
-import { queryByAPI } from './helpers/queryByAPI';
-import { findByAPI } from './helpers/findByAPI';
-import a11yAPI from './helpers/a11yAPI';
+import { getByAPI, type GetByAPI } from './helpers/getByAPI';
+import { queryByAPI, type QueryByAPI } from './helpers/queryByAPI';
+import { findByAPI, type FindByAPI } from './helpers/findByAPI';
+import { a11yAPI, type A11yAPI } from './helpers/a11yAPI';
 import debugShallow from './helpers/debugShallow';
 import debugDeep from './helpers/debugDeep';
 
@@ -25,7 +25,18 @@ type TestRendererOptions = {
 export default function render<T>(
   component: React.Element<T>,
   { wrapper: Wrapper, createNodeMock }: Options = {}
-) {
+): {
+  ...FindByAPI,
+  ...QueryByAPI,
+  ...GetByAPI,
+  ...A11yAPI,
+  update: (component: React.Element<any>) => void,
+  container: ReactTestInstance,
+  rerender: (component: React.Element<any>) => void,
+  unmount: (nextElement?: React.Element<any>) => void,
+  toJSON: () => null | ReactTestRendererJSON,
+  debug: DebugFunction,
+} {
   const wrap = (innerElement: React.Element<any>) =>
     Wrapper ? <Wrapper>{innerElement}</Wrapper> : innerElement;
 
@@ -76,7 +87,15 @@ function updateWithAct(
   };
 }
 
-function debug(instance: ReactTestInstance, renderer) {
+interface DebugFunction {
+  (message?: string): void;
+  shallow: (message?: string) => void;
+}
+
+function debug(
+  instance: ReactTestInstance,
+  renderer: ReactTestRenderer
+): DebugFunction {
   function debugImpl(message?: string) {
     return debugDeep(renderer.toJSON(), message);
   }

src/shallow.js

@@ -8,7 +8,7 @@ import { throwRemovedFunctionError } from './helpers/errors';
  */
 export function shallowInternal(
   instance: ReactTestInstance | React.Element<any>
-) {
+): {| output: any |} {
   const renderer = new ShallowRenderer();
 
   renderer.render(React.createElement(instance.type, instance.props));

src/types.flow.js

@@ -1,5 +1,9 @@
 // @flow
 
+export type Thenable = {
+  then(resolve: () => mixed, reject?: () => mixed): mixed,
+};
+
 export type A11yRole =
   | 'none'
   | 'button'

src/waitForElementToBeRemoved.js

@@ -2,8 +2,9 @@
 import waitFor, { type WaitForOptions } from './waitFor';
 import { ErrorWithStack } from './helpers/errors';
 
-const isRemoved = (result) =>
-  !result || (Array.isArray(result) && !result.length);
+function isRemoved<T>(result: T): boolean {
+  return !result || (Array.isArray(result) && !result.length);
+}
 
 export default async function waitForElementToBeRemoved<T>(
   expectation: () => T,

src/within.js

@@ -1,10 +1,12 @@
 // @flow
-import { getByAPI } from './helpers/getByAPI';
-import { queryByAPI } from './helpers/queryByAPI';
-import { findByAPI } from './helpers/findByAPI';
-import a11yAPI from './helpers/a11yAPI';
+import { getByAPI, type GetByAPI } from './helpers/getByAPI';
+import { queryByAPI, type QueryByAPI } from './helpers/queryByAPI';
+import { findByAPI, type FindByAPI } from './helpers/findByAPI';
+import { a11yAPI, type A11yAPI } from './helpers/a11yAPI';
 
-export function within(instance: ReactTestInstance) {
+export function within(
+  instance: ReactTestInstance
+): { ...FindByAPI, ...QueryByAPI, ...GetByAPI, ...A11yAPI } {
   return {
     ...getByAPI(instance),
     ...queryByAPI(instance),