fix: "union too complex to represent" for large union types (#571)

Closes #503
Co-authored-by: Jason Kuhrt <jasonkuhrt@me.com>

jest.config.js

@@ -1,9 +1,8 @@
 const path = require('path')
-const { env } = require('process')
+const process = require('process')
 
-/**
- * @type {jest.InitialOptions}
- */
+/** @typedef {import('ts-jest')} */
+/** @type {import('@jest/types').Config.InitialOptions} */
 module.exports = {
   setupFilesAfterEnv: ['<rootDir>/tests/_setup.ts'],
   preset: 'ts-jest',
@@ -11,8 +10,12 @@ module.exports = {
   watchPlugins: ['jest-watch-typeahead/filename', 'jest-watch-typeahead/testname'],
   globals: {
     'ts-jest': {
-      diagnostics: Boolean(process.env.CI),
-      tsConfig: path.join(__dirname, 'tests/tsconfig.json'),
+      diagnostics: Boolean(process.env.CI)
+        ? {
+            pretty: true,
+            pathRegex: '\\.(spec|test)\\.ts$',
+          }
+        : false,
     },
   },
   collectCoverageFrom: ['src/**/*'],

src/typegenTypeHelpers.ts

@@ -164,33 +164,20 @@ export type GetGen<K extends GenTypesShapeKeys, Fallback = any> = NexusGen exten
 
 export type GetGen2<
   K extends GenTypesShapeKeys,
-  K2 extends keyof GenTypesShape[K]
-> = NexusGen extends infer GenTypes
-  ? GenTypes extends GenTypesShape
-    ? K extends keyof GenTypes
-      ? K2 extends keyof GenTypes[K]
-        ? GenTypes[K][K2]
-        : any
-      : any
-    : any
-  : any
+  K2 extends Extract<keyof GenTypesShape[K], string>,
+  Fallback = any
+> = K2 extends keyof GetGen<K, never> ? GetGen<K>[K2] : Fallback
 
 export type GetGen3<
   K extends GenTypesShapeKeys,
   K2 extends Extract<keyof GenTypesShape[K], string>,
   K3 extends Extract<keyof GenTypesShape[K][K2], string>,
   Fallback = any
-> = NexusGen extends infer GenTypes
-  ? GenTypes extends GenTypesShape
-    ? K extends keyof GenTypes
-      ? K2 extends keyof GenTypes[K]
-        ? K3 extends keyof GenTypes[K][K2]
-          ? GenTypes[K][K2][K3]
+> = K2 extends keyof GetGen<K, never>
+  ? K3 extends keyof GetGen<K>[K2]
+    ? GetGen<K>[K2][K3]
+    : Fallback
   : Fallback
-        : any
-      : any
-    : any
-  : any
 
 export type HasGen<K extends GenTypesShapeKeys> = NexusGen extends infer GenTypes
   ? GenTypes extends GenTypesShape

src/utils.ts

@@ -22,8 +22,8 @@ import {
   specifiedScalarTypes,
 } from 'graphql'
 import * as path from 'path'
-import { decorateType } from './definitions/decorateType'
 import { MissingType, NexusTypes, withNexusSymbol } from './definitions/_types'
+import { decorateType } from './definitions/decorateType'
 import { PluginConfig } from './plugin'
 
 export const isInterfaceField = (type: GraphQLObjectType, fieldName: string) => {
@@ -420,3 +420,10 @@ export function casesHandled(x: never): never {
  * Is the given type equal to the other given type?
  */
 export type IsEqual<A, B> = A extends B ? (B extends A ? true : false) : false
+
+/**
+ * Quickly log objects
+ */
+export function dump(x: any) {
+  console.log(require('util').inspect(x, { depth: null }))
+}

tests/__helpers/testApp.ts

@@ -1,7 +1,7 @@
 /// <reference path="../_setup.ts" />
 import { join } from 'path'
-import * as ts from 'typescript'
 import { core } from '../../src'
+
 const { generateSchema, typegenFormatPrettier } = core
 
 type Settings = {
@@ -16,16 +16,16 @@ type Settings = {
  * - By default looks for an `__app.ts` entrypoint
  * - All entrypoint exports are expected to be Nexus type definitions
  * - Except the optional export name "plugins" which is treated as an array of plugins for makeSchema
- * - The typegen module will be automatically included into the TypeScript build, no need to import it
+ * - Outputs a `__typegen.ts` typegen module
+ * - You must import the typegen module into your entrypoint module
+ * - If you provide a `tsconfig.json` file in the root dir it will be used.
  */
 export const testApp = (settings: Settings) => {
   const name = settings?.name ?? 'app'
   const rootDir = settings.rootDir
 
-  const typegenModuleName = '__typegen'
-  const typegenModulePath = join(rootDir, `${typegenModuleName}.ts`)
-  const entrypointModuleName = `__app`
-  const entrypointModulePath = join(rootDir, `${entrypointModuleName}.ts`)
+  const typegenModulePath = join(rootDir, '__typegen.ts')
+  const entrypointModulePath = join(rootDir, '__app.ts')
 
   const entrypoint = require(entrypointModulePath)
   const { plugins, ...types } = entrypoint
@@ -40,22 +40,16 @@ export const testApp = (settings: Settings) => {
       shouldGenerateArtifacts: true,
       plugins: plugins || [],
       async formatTypegen(source, type) {
-        const content = await typegenFormatPrettier({
-          trailingComma: 'es5',
-          arrowParens: 'always',
-        })(source, type)
-        return content.replace('"@nexus/schema"', '"../../.."')
+        const prettierConfigPath = require.resolve('../../.prettierrc')
+        const content = await typegenFormatPrettier(prettierConfigPath)(source, type)
+
+        return content.replace("'@nexus/schema'", "'../../..'")
       },
     })
   })
 
   it(`can compile ${name} app with its typegen`, async () => {
-    expect([entrypointModulePath, typegenModulePath]).toTypeCheck({
-      downlevelIteration: true,
-      noEmitOnError: true,
-      strict: true,
-      target: ts.ScriptTarget.ES5,
-      noErrorTruncation: false,
+    expect({ rootDir }).toTypeCheck({
       outDir: `/tmp/nexus-integration-test-${Date.now()}`,
     })
   })

tests/_setup.ts

@@ -1,5 +1,8 @@
+import * as fs from 'fs-jetpack'
+import * as Path from 'path'
 import * as tsm from 'ts-morph'
 import * as ts from 'typescript'
+
 ;(global as any).TS_FORMAT_PROJECT_ROOT = 'src/'
 
 const formatTSDiagonsticsForJest = (diagnostics: readonly ts.Diagnostic[]): string => {
@@ -23,9 +26,33 @@ const formatTSDiagonsticsForJest = (diagnostics: readonly ts.Diagnostic[]): stri
 }
 
 expect.extend({
-  toTypeCheck(fileNames: string | string[], compilerOptions: tsm.CompilerOptions) {
-    const project = new tsm.Project({ compilerOptions: compilerOptions })
-    project.addSourceFilesAtPaths(Array.isArray(fileNames) ? fileNames : [fileNames])
+  toTypeCheck(input: string | string[] | { rootDir: string }, compilerOptions: tsm.CompilerOptions) {
+    let rootDir
+    let fileNames: string[]
+    if (typeof input !== 'string' && !Array.isArray(input)) {
+      rootDir = input.rootDir
+      fileNames = []
+    } else {
+      fileNames = Array.isArray(input) ? input : [input]
+      rootDir = Path.dirname(fileNames[0])
+    }
+
+    // check for tsconfig
+    let tsConfigFilePath
+    const maybeTsConfigFilePath = `${rootDir}/tsconfig.json`
+    if (fs.exists(maybeTsConfigFilePath)) {
+      tsConfigFilePath = maybeTsConfigFilePath
+    }
+
+    const project = new tsm.Project({
+      tsConfigFilePath,
+      compilerOptions,
+      addFilesFromTsConfig: true,
+    })
+
+    if (fileNames.length) {
+      project.addSourceFilesAtPaths(fileNames)
+    }
 
     const preEmitDiagnostics = project.getPreEmitDiagnostics()
     const emitDiagnostics = project.emitSync().getDiagnostics()
@@ -36,8 +63,9 @@ expect.extend({
       message: () =>
         pass
           ? 'expected program to not typecheck'
-          : (project.formatDiagnosticsWithColorAndContext(preEmitDiagnostics),
-            project.formatDiagnosticsWithColorAndContext(emitDiagnostics)),
+          : project.formatDiagnosticsWithColorAndContext(preEmitDiagnostics) +
+            '\n\n\n' +
+            project.formatDiagnosticsWithColorAndContext(emitDiagnostics),
       pass,
     }
   },

tests/dynamicMethods.spec.ts

@@ -13,7 +13,6 @@ import {
 import { dynamicOutputProperty } from '../src/dynamicProperty'
 import { CatListFixture } from './_fixtures'
 
-let spy: jest.SpyInstance
 beforeEach(() => {
   jest.clearAllMocks()
 })

tests/integrations/kitchenSink/__app.ts

@@ -1,3 +1,4 @@
+import './__typegen'
 import {
   dynamicInputMethod,
   dynamicOutputMethod,

tests/integrations/kitchenSink/__typegen.ts

@@ -97,6 +97,40 @@ export interface NexusGenFieldTypes {
   }
 }
 
+export interface NexusGenFieldTypeNames {
+  Mutation: {
+    // field return type name
+    createUser: 'User'
+  }
+  Post: {
+    // field return type name
+    body: 'String'
+    title: 'String'
+  }
+  Query: {
+    // field return type name
+    foo: 'String'
+    searchPosts: 'Post'
+    user: 'User'
+  }
+  Subscription: {
+    // field return type name
+    someBoolean: 'Boolean'
+    someField: 'Int'
+    someFields: 'Int'
+    someFloat: 'Float'
+    someID: 'ID'
+    someInt: 'Int'
+    someInts: 'Int'
+    someString: 'String'
+  }
+  User: {
+    // field return type name
+    firstName: 'String'
+    lastName: 'String'
+  }
+}
+
 export interface NexusGenArgTypes {
   Mutation: {
     createUser: {
@@ -139,6 +173,7 @@ export interface NexusGenTypes {
   rootTypes: NexusGenRootTypes
   argTypes: NexusGenArgTypes
   fieldTypes: NexusGenFieldTypes
+  fieldTypeNames: NexusGenFieldTypeNames
   allTypes: NexusGenAllTypes
   inheritedFields: NexusGenInheritedFields
   objectNames: NexusGenObjectNames

tests/integrations/kitchenSink/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "rootDir": "../../..",
+    "target": "ES2015",
+    "moduleResolution": "node"
+  },
+  "include": ["__app.ts"]
+}

tests/integrations/unionTooComplexToRepresent/__app.ts

@@ -1,3 +1,4 @@
+import './__typegen'
 import { objectType, unionType } from '../../../src'
 
 export const typeNames = [
@@ -315,7 +316,7 @@ export const types = [
   unionType({
     name: 'BigUnion',
     definition(t) {
-      t.members(...(typeNames as any))
+      t.members(...typeNames)
       t.resolveType(() => null)
     },
   }),

tests/integrations/unionTooComplexToRepresent/case.spec.ts

@@ -0,0 +1,5 @@
+import { testApp } from '../../__helpers/testApp'
+
+testApp({
+  rootDir: __dirname,
+})

tests/integrations/unionTooComplexToRepresent/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "target": "ES2015",
+    "rootDir": "../../../",
+    "moduleResolution": "node"
+  },
+  "include": ["__app.ts"]
+}

tests/integrations/unionTooLargeToRepresent/case.test.ts

@@ -1,7 +0,0 @@
-// import { testApp } from '../../__helpers/testApp'
-
-// testApp({
-//   rootDir: __dirname,
-// })
-
-it.todo('fixme')

tests/plugins/connectionPlugin.spec.ts

@@ -90,14 +90,6 @@ beforeEach(() => {
   jest.resetAllMocks()
 })
 
-function toBase64(x: string): string {
-  return new Buffer(x).toString('base64')
-}
-
-function dump(x: any) {
-  console.log(require('util').inspect(x, { depth: null }))
-}
-
 describe('defaults', () => {
   it('hasPreviousPage when paginating backwards assumes that node count equal to page size means there is another page to visit backward', async () => {
     const schema = makeTestSchema(

tests/tsconfig.json

@@ -1,9 +0,0 @@
-{
-  "extends": "../tsconfig.json",
-  "compilerOptions": {
-    "noUnusedLocals": false, // FIXME
-    "noEmit": true,
-    "rootDir": "."
-  },
-  "include": ["**/*.ts"]
-}