From 1f3c34426cea6d04df2393032e0728ade7390d3c Mon Sep 17 00:00:00 2001
From: Brad Zacher <brad.zacher@gmail.com>
Date: Sun, 3 May 2020 22:19:55 -0700
Subject: [PATCH] chore: upgrade to prettier 2.0 (#1970)

---
 .github/workflows/ci.yml                      |   3 +-
 .prettierrc.json                              |  13 +-
 package.json                                  |   3 +-
 .../rules/explicit-function-return-type.md    |  12 +-
 .../rules/explicit-module-boundary-types.md   |  16 +--
 .../docs/rules/no-explicit-any.md             |   4 +-
 .../docs/rules/no-floating-promises.md        |   4 +-
 .../docs/rules/no-implied-eval.md             |  10 +-
 .../eslint-plugin/docs/rules/no-this-alias.md |   2 +-
 packages/eslint-plugin/docs/rules/typedef.md  |   8 +-
 packages/eslint-plugin/package.json           |   2 -
 .../src/rules/consistent-type-assertions.ts   |   1 -
 .../rules/explicit-member-accessibility.ts    |   2 +-
 .../no-unnecessary-boolean-literal-compare.ts |   2 +-
 .../src/rules/no-unnecessary-qualifier.ts     |   2 +-
 .../adjacent-overload-signatures.test.ts      |   2 +-
 .../tests/rules/default-param-last.test.ts    | 112 +++++++--------
 .../explicit-function-return-type.test.ts     |  58 ++++----
 .../explicit-module-boundary-types.test.ts    |  50 +++----
 .../tests/rules/init-declarations.test.ts     |   8 +-
 .../rules/method-signature-style.test.ts      |   3 +-
 .../tests/rules/no-explicit-any.test.ts       |   8 +-
 .../tests/rules/no-floating-promises.test.ts  |  12 +-
 .../tests/rules/no-implied-eval.test.ts       |  16 +--
 .../tests/rules/no-inferrable-types.test.ts   |   6 +-
 .../tests/rules/no-invalid-this.test.ts       | 134 +++++++++---------
 .../tests/rules/no-unused-vars.test.ts        |   2 +-
 .../tests/rules/no-use-before-define.test.ts  |  10 +-
 .../tests/rules/prefer-readonly.test.ts       |   2 +-
 .../rules/promise-function-async.test.ts      |  16 +--
 .../tests/rules/require-await.test.ts         |  24 ++--
 .../eslint-plugin/tests/rules/typedef.test.ts |  10 +-
 .../tests/rules/unbound-method.test.ts        |   2 +-
 .../tests/rules/unified-signatures.test.ts    |  16 +--
 packages/parser/src/analyze-scope.ts          |   2 +-
 yarn.lock                                     |  16 +--
 36 files changed, 301 insertions(+), 292 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3e2d0e9dd51..62502349d9f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -167,7 +167,8 @@ jobs:
           yarn check-clean-workspace-after-install
 
       - name: Run unit tests
-        run: yarn test
+        # the internal plugin is only run locally, so it doesn't have to support older versions
+        run: yarn test --ignore @typescript-eslint/eslint-plugin-internal
         env:
           CI: true
 
diff --git a/.prettierrc.json b/.prettierrc.json
index a20502b7f06..2fdcda48cf4 100644
--- a/.prettierrc.json
+++ b/.prettierrc.json
@@ -1,4 +1,15 @@
 {
+  "arrowParens": "avoid",
+  "bracketSpacing": true,
+  "endOfLine": "lf",
+  "jsxBracketSameLine": false,
+  "jsxSingleQuote": false,
+  "printWidth": 80,
+  "proseWrap": "preserve",
+  "quoteProps": "as-needed",
+  "semi": true,
   "singleQuote": true,
-  "trailingComma": "all"
+  "tabWidth": 2,
+  "trailingComma": "all",
+  "useTabs": false
 }
diff --git a/package.json b/package.json
index d0ecaef0fa5..9f87c2c1d48 100644
--- a/package.json
+++ b/package.json
@@ -59,6 +59,7 @@
     "@commitlint/config-lerna-scopes": "^8.3.4",
     "@types/jest": "^25.1.0",
     "@types/node": "^12.12.7",
+    "@types/prettier": "^2.0.0",
     "all-contributors-cli": "^6.11.0",
     "cspell": "^4.0.43",
     "cz-conventional-changelog": "^3.0.2",
@@ -73,7 +74,7 @@
     "lerna": "^3.20.2",
     "lint-staged": "^9.4.3",
     "markdownlint-cli": "^0.22.0",
-    "prettier": "^1.19.1",
+    "prettier": "^2.0.5",
     "ts-jest": "^25.0.0",
     "ts-node": "^8.5.0",
     "tslint": "^6.1.0",
diff --git a/packages/eslint-plugin/docs/rules/explicit-function-return-type.md b/packages/eslint-plugin/docs/rules/explicit-function-return-type.md
index a0e4ebce5ea..5e60f29eac2 100644
--- a/packages/eslint-plugin/docs/rules/explicit-function-return-type.md
+++ b/packages/eslint-plugin/docs/rules/explicit-function-return-type.md
@@ -18,7 +18,7 @@ function test() {
 }
 
 // Should indicate that a number is returned
-var fn = function() {
+var fn = function () {
   return 1;
 };
 
@@ -42,7 +42,7 @@ function test(): void {
 }
 
 // A return value of type number
-var fn = function(): number {
+var fn = function (): number {
   return 1;
 };
 
@@ -119,7 +119,7 @@ Examples of **correct** code for this rule with `{ allowExpressions: true }`:
 ```ts
 node.addEventListener('click', () => {});
 
-node.addEventListener('click', function() {});
+node.addEventListener('click', function () {});
 
 const foo = arr.map(i => i * i);
 ```
@@ -131,7 +131,7 @@ Examples of **incorrect** code for this rule with `{ allowTypedFunctionExpressio
 ```ts
 let arrowFn = () => 'test';
 
-let funcExpr = function() {
+let funcExpr = function () {
   return 'test';
 };
 
@@ -186,7 +186,7 @@ Examples of **incorrect** code for this rule with `{ allowHigherOrderFunctions:
 var arrowFn = () => () => {};
 
 function fn() {
-  return function() {};
+  return function () {};
 }
 ```
 
@@ -196,7 +196,7 @@ Examples of **correct** code for this rule with `{ allowHigherOrderFunctions: tr
 var arrowFn = () => (): void => {};
 
 function fn() {
-  return function(): void {};
+  return function (): void {};
 }
 ```
 
diff --git a/packages/eslint-plugin/docs/rules/explicit-module-boundary-types.md b/packages/eslint-plugin/docs/rules/explicit-module-boundary-types.md
index 3c077a75c88..5a33f9e9a35 100644
--- a/packages/eslint-plugin/docs/rules/explicit-module-boundary-types.md
+++ b/packages/eslint-plugin/docs/rules/explicit-module-boundary-types.md
@@ -17,7 +17,7 @@ export function test() {
 }
 
 // Should indicate that a number is returned
-export default function() {
+export default function () {
   return 1;
 }
 
@@ -44,7 +44,7 @@ function test() {
 }
 
 // A return value of type number
-export var fn = function(): number {
+export var fn = function (): number {
   return 1;
 };
 
@@ -129,7 +129,7 @@ Examples of **incorrect** code for this rule with `{ allowTypedFunctionExpressio
 ```ts
 export let arrowFn = () => 'test';
 
-export let funcExpr = function() {
+export let funcExpr = function () {
   return 'test';
 };
 
@@ -147,7 +147,7 @@ type FuncType = () => string;
 
 export let arrowFn: FuncType = () => 'test';
 
-export let funcExpr: FuncType = function() {
+export let funcExpr: FuncType = function () {
   return 'test';
 };
 
@@ -179,11 +179,11 @@ Examples of **incorrect** code for this rule with `{ allowHigherOrderFunctions:
 export var arrowFn = () => () => {};
 
 export function fn() {
-  return function() {};
+  return function () {};
 }
 
 export function foo(outer) {
-  return function(inner): void {};
+  return function (inner): void {};
 }
 ```
 
@@ -193,11 +193,11 @@ Examples of **correct** code for this rule with `{ allowHigherOrderFunctions: tr
 export var arrowFn = () => (): void => {};
 
 export function fn() {
-  return function(): void {};
+  return function (): void {};
 }
 
 export function foo(outer: string) {
-  return function(inner: string): void {};
+  return function (inner: string): void {};
 }
 ```
 
diff --git a/packages/eslint-plugin/docs/rules/no-explicit-any.md b/packages/eslint-plugin/docs/rules/no-explicit-any.md
index c440d3bdc60..7aeb465874e 100644
--- a/packages/eslint-plugin/docs/rules/no-explicit-any.md
+++ b/packages/eslint-plugin/docs/rules/no-explicit-any.md
@@ -122,7 +122,7 @@ function foo4(...args: ReadonlyArray<any>): void {}
 declare function bar(...args: any[]): void;
 
 const baz = (...args: any[]) => {};
-const qux = function(...args: any[]) {};
+const qux = function (...args: any[]) {};
 
 type Quux = (...args: any[]) => void;
 type Quuz = new (...args: any[]) => void;
@@ -151,7 +151,7 @@ function foo4(...args: ReadonlyArray<any>): void {}
 declare function bar(...args: any[]): void;
 
 const baz = (...args: any[]) => {};
-const qux = function(...args: any[]) {};
+const qux = function (...args: any[]) {};
 
 type Quux = (...args: any[]) => void;
 type Quuz = new (...args: any[]) => void;
diff --git a/packages/eslint-plugin/docs/rules/no-floating-promises.md b/packages/eslint-plugin/docs/rules/no-floating-promises.md
index 4ea2e6addc9..9ed1f23455a 100644
--- a/packages/eslint-plugin/docs/rules/no-floating-promises.md
+++ b/packages/eslint-plugin/docs/rules/no-floating-promises.md
@@ -83,11 +83,11 @@ This allows you to skip checking of async iife
 Examples of **correct** code for this rule with `{ ignoreIIFE: true }`:
 
 ```ts
-await(async function() {
+await(async function () {
   await res(1);
 })();
 
-(async function() {
+(async function () {
   await res(1);
 })();
 ```
diff --git a/packages/eslint-plugin/docs/rules/no-implied-eval.md b/packages/eslint-plugin/docs/rules/no-implied-eval.md
index a16844a6d43..3753adf26d7 100644
--- a/packages/eslint-plugin/docs/rules/no-implied-eval.md
+++ b/packages/eslint-plugin/docs/rules/no-implied-eval.md
@@ -56,19 +56,19 @@ Examples of **correct** code for this rule:
 ```ts
 /* eslint @typescript-eslint/no-implied-eval: "error" */
 
-setTimeout(function() {
+setTimeout(function () {
   alert('Hi!');
 }, 100);
 
-setInterval(function() {
+setInterval(function () {
   alert('Hi!');
 }, 100);
 
-setImmediate(function() {
+setImmediate(function () {
   alert('Hi!');
 });
 
-execScript(function() {
+execScript(function () {
   alert('Hi!');
 });
 
@@ -76,7 +76,7 @@ const fn = () => {};
 setTimeout(fn, 100);
 
 const foo = {
-  fn: function() {},
+  fn: function () {},
 };
 setTimeout(foo.fn, 100);
 setTimeout(foo.fn.bind(this), 100);
diff --git a/packages/eslint-plugin/docs/rules/no-this-alias.md b/packages/eslint-plugin/docs/rules/no-this-alias.md
index b5d2afb542c..324929e52c2 100644
--- a/packages/eslint-plugin/docs/rules/no-this-alias.md
+++ b/packages/eslint-plugin/docs/rules/no-this-alias.md
@@ -14,7 +14,7 @@ Rationale from TSLint:
 > ```js
 > const self = this;
 >
-> setTimeout(function() {
+> setTimeout(function () {
 >   self.doWork();
 > });
 > ```
diff --git a/packages/eslint-plugin/docs/rules/typedef.md b/packages/eslint-plugin/docs/rules/typedef.md
index 07f4bb1eb3a..594f7b65e7d 100644
--- a/packages/eslint-plugin/docs/rules/typedef.md
+++ b/packages/eslint-plugin/docs/rules/typedef.md
@@ -164,7 +164,7 @@ function logsSize(size): void {
   console.log(size);
 }
 
-const doublesSize = function(size): number {
+const doublesSize = function (size): number {
   return size * 2;
 };
 
@@ -172,7 +172,7 @@ const divider = {
   curriesSize(size): number {
     return size;
   },
-  dividesSize: function(size): number {
+  dividesSize: function (size): number {
     return size / 2;
   },
 };
@@ -192,7 +192,7 @@ function logsSize(size: number): void {
   console.log(size);
 }
 
-const doublesSize = function(size: number): number {
+const doublesSize = function (size: number): number {
   return size * 2;
 };
 
@@ -200,7 +200,7 @@ const divider = {
   curriesSize(size: number): number {
     return size;
   },
-  dividesSize: function(size: number): number {
+  dividesSize: function (size: number): number {
     return size / 2;
   },
 };
diff --git a/packages/eslint-plugin/package.json b/packages/eslint-plugin/package.json
index 6c359a6dd97..18f4a5dc8c5 100644
--- a/packages/eslint-plugin/package.json
+++ b/packages/eslint-plugin/package.json
@@ -47,9 +47,7 @@
     "tsutils": "^3.17.1"
   },
   "devDependencies": {
-    "@types/json-schema": "^7.0.3",
     "@types/marked": "^0.7.1",
-    "@types/prettier": "^1.18.2",
     "chalk": "^3.0.0",
     "marked": "^0.7.0",
     "prettier": "*",
diff --git a/packages/eslint-plugin/src/rules/consistent-type-assertions.ts b/packages/eslint-plugin/src/rules/consistent-type-assertions.ts
index 0620822f83c..2457bdb08a9 100644
--- a/packages/eslint-plugin/src/rules/consistent-type-assertions.ts
+++ b/packages/eslint-plugin/src/rules/consistent-type-assertions.ts
@@ -10,7 +10,6 @@ type MessageIds =
   | 'angle-bracket'
   | 'never'
   | 'unexpectedObjectTypeAssertion';
-// https://github.com/prettier/prettier/issues/4794
 type OptUnion =
   | {
       assertionStyle: 'as' | 'angle-bracket';
diff --git a/packages/eslint-plugin/src/rules/explicit-member-accessibility.ts b/packages/eslint-plugin/src/rules/explicit-member-accessibility.ts
index 7c49f0d6a31..23ac95814c0 100644
--- a/packages/eslint-plugin/src/rules/explicit-member-accessibility.ts
+++ b/packages/eslint-plugin/src/rules/explicit-member-accessibility.ts
@@ -166,7 +166,7 @@ export default util.createRule<Options, MessageIds>({
         | TSESTree.ClassProperty
         | TSESTree.TSParameterProperty,
     ): TSESLint.ReportFixFunction {
-      return function(fixer: TSESLint.RuleFixer): TSESLint.RuleFix {
+      return function (fixer: TSESLint.RuleFixer): TSESLint.RuleFix {
         const tokens = sourceCode.getTokens(node);
         let rangeToRemove: TSESLint.AST.Range;
         for (let i = 0; i < tokens.length; i++) {
diff --git a/packages/eslint-plugin/src/rules/no-unnecessary-boolean-literal-compare.ts b/packages/eslint-plugin/src/rules/no-unnecessary-boolean-literal-compare.ts
index 1cd03962ae4..ffcdd0e0732 100644
--- a/packages/eslint-plugin/src/rules/no-unnecessary-boolean-literal-compare.ts
+++ b/packages/eslint-plugin/src/rules/no-unnecessary-boolean-literal-compare.ts
@@ -106,7 +106,7 @@ export default util.createRule<[], MessageIds>({
 
         if (comparison) {
           context.report({
-            fix: function*(fixer) {
+            fix: function* (fixer) {
               yield fixer.removeRange(comparison.range);
 
               if (!comparison.forTruthy) {
diff --git a/packages/eslint-plugin/src/rules/no-unnecessary-qualifier.ts b/packages/eslint-plugin/src/rules/no-unnecessary-qualifier.ts
index a34533d2fc2..395bbfdc4f3 100644
--- a/packages/eslint-plugin/src/rules/no-unnecessary-qualifier.ts
+++ b/packages/eslint-plugin/src/rules/no-unnecessary-qualifier.ts
@@ -179,7 +179,7 @@ export default util.createRule({
       TSQualifiedName(node: TSESTree.TSQualifiedName): void {
         visitNamespaceAccess(node, node.left, node.right);
       },
-      'MemberExpression[computed=false]': function(
+      'MemberExpression[computed=false]': function (
         node: TSESTree.MemberExpression,
       ): void {
         const property = node.property as TSESTree.Identifier;
diff --git a/packages/eslint-plugin/tests/rules/adjacent-overload-signatures.test.ts b/packages/eslint-plugin/tests/rules/adjacent-overload-signatures.test.ts
index 8e844bb96be..55fea63fb11 100644
--- a/packages/eslint-plugin/tests/rules/adjacent-overload-signatures.test.ts
+++ b/packages/eslint-plugin/tests/rules/adjacent-overload-signatures.test.ts
@@ -221,7 +221,7 @@ class Test {
 }
     `,
     // examples from https://github.com/nzakas/eslint-plugin-typescript/issues/138
-    'export default function<T>(foo: T) {}',
+    'export default function <T>(foo: T) {}',
     'export default function named<T>(foo: T) {}',
     `
 interface Foo {
diff --git a/packages/eslint-plugin/tests/rules/default-param-last.test.ts b/packages/eslint-plugin/tests/rules/default-param-last.test.ts
index 76e23bbe8a7..aa0ffbc8743 100644
--- a/packages/eslint-plugin/tests/rules/default-param-last.test.ts
+++ b/packages/eslint-plugin/tests/rules/default-param-last.test.ts
@@ -19,17 +19,17 @@ ruleTester.run('default-param-last', rule, {
     'function foo(a: number, b?: number, c = 1) {}',
     'function foo(a: number, b = 1, ...c) {}',
 
-    'const foo = function() {};',
-    'const foo = function(a: number) {};',
-    'const foo = function(a = 1) {};',
-    'const foo = function(a?: number) {};',
-    'const foo = function(a: number, b: number) {};',
-    'const foo = function(a: number, b: number, c?: number) {};',
-    'const foo = function(a: number, b = 1) {};',
-    'const foo = function(a: number, b = 1, c = 1) {};',
-    'const foo = function(a: number, b = 1, c?: number) {};',
-    'const foo = function(a: number, b?: number, c = 1) {};',
-    'const foo = function(a: number, b = 1, ...c) {};',
+    'const foo = function () {};',
+    'const foo = function (a: number) {};',
+    'const foo = function (a = 1) {};',
+    'const foo = function (a?: number) {};',
+    'const foo = function (a: number, b: number) {};',
+    'const foo = function (a: number, b: number, c?: number) {};',
+    'const foo = function (a: number, b = 1) {};',
+    'const foo = function (a: number, b = 1, c = 1) {};',
+    'const foo = function (a: number, b = 1, c?: number) {};',
+    'const foo = function (a: number, b?: number, c = 1) {};',
+    'const foo = function (a: number, b = 1, ...c) {};',
 
     'const foo = () => {};',
     'const foo = (a: number) => {};',
@@ -251,163 +251,163 @@ class Foo {
       ],
     },
     {
-      code: 'const foo = function(a = 1, b: number) {};',
+      code: 'const foo = function (a = 1, b: number) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
       ],
     },
     {
-      code: 'const foo = function(a = 1, b = 2, c: number) {};',
+      code: 'const foo = function (a = 1, b = 2, c: number) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 29,
-          endColumn: 34,
+          column: 30,
+          endColumn: 35,
         },
       ],
     },
     {
-      code: 'const foo = function(a = 1, b: number, c = 2, d: number) {};',
+      code: 'const foo = function (a = 1, b: number, c = 2, d: number) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 40,
-          endColumn: 45,
+          column: 41,
+          endColumn: 46,
         },
       ],
     },
     {
-      code: 'const foo = function(a = 1, b: number, c = 2) {};',
+      code: 'const foo = function (a = 1, b: number, c = 2) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
       ],
     },
     {
-      code: 'const foo = function(a = 1, b: number, ...c) {};',
+      code: 'const foo = function (a = 1, b: number, ...c) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
       ],
     },
     {
-      code: 'const foo = function(a?: number, b: number) {};',
+      code: 'const foo = function (a?: number, b: number) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 32,
+          column: 23,
+          endColumn: 33,
         },
       ],
     },
     {
-      code: 'const foo = function(a: number, b?: number, c: number) {};',
+      code: 'const foo = function (a: number, b?: number, c: number) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 33,
-          endColumn: 43,
+          column: 34,
+          endColumn: 44,
         },
       ],
     },
     {
-      code: 'const foo = function(a = 1, b?: number, c: number) {};',
+      code: 'const foo = function (a = 1, b?: number, c: number) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 29,
-          endColumn: 39,
+          column: 30,
+          endColumn: 40,
         },
       ],
     },
     {
-      code: 'const foo = function(a = 1, { b }) {};',
+      code: 'const foo = function (a = 1, { b }) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 27,
+          column: 23,
+          endColumn: 28,
         },
       ],
     },
     {
-      code: 'const foo = function({ a } = {}, b) {};',
+      code: 'const foo = function ({ a } = {}, b) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 32,
+          column: 23,
+          endColumn: 33,
         },
       ],
     },
     {
-      code: 'const foo = function({ a, b } = { a: 1, b: 2 }, c) {};',
+      code: 'const foo = function ({ a, b } = { a: 1, b: 2 }, c) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 47,
+          column: 23,
+          endColumn: 48,
         },
       ],
     },
     {
-      code: 'const foo = function([a] = [], b) {};',
+      code: 'const foo = function ([a] = [], b) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 30,
+          column: 23,
+          endColumn: 31,
         },
       ],
     },
     {
-      code: 'const foo = function([a, b] = [1, 2], c) {};',
+      code: 'const foo = function ([a, b] = [1, 2], c) {};',
       errors: [
         {
           messageId: 'shouldBeLast',
           line: 1,
-          column: 22,
-          endColumn: 37,
+          column: 23,
+          endColumn: 38,
         },
       ],
     },
diff --git a/packages/eslint-plugin/tests/rules/explicit-function-return-type.test.ts b/packages/eslint-plugin/tests/rules/explicit-function-return-type.test.ts
index dd3e3815676..6ce8210822b 100644
--- a/packages/eslint-plugin/tests/rules/explicit-function-return-type.test.ts
+++ b/packages/eslint-plugin/tests/rules/explicit-function-return-type.test.ts
@@ -18,7 +18,7 @@ function test(): void {
     {
       filename: 'test.ts',
       code: `
-var fn = function(): number {
+var fn = function (): number {
   return 1;
 };
       `,
@@ -56,7 +56,7 @@ class Test {
     },
     {
       filename: 'test.ts',
-      code: 'fn(function() {});',
+      code: 'fn(function () {});',
       options: [
         {
           allowExpressions: true,
@@ -65,7 +65,7 @@ class Test {
     },
     {
       filename: 'test.ts',
-      code: '[function() {}, () => {}];',
+      code: '[function () {}, () => {}];',
       options: [
         {
           allowExpressions: true,
@@ -74,7 +74,7 @@ class Test {
     },
     {
       filename: 'test.ts',
-      code: '(function() {});',
+      code: '(function () {});',
       options: [
         {
           allowExpressions: true,
@@ -113,7 +113,7 @@ var arrowFn: Foo = () => 'test';
     {
       filename: 'test.ts',
       code: `
-var funcExpr: Foo = function() {
+var funcExpr: Foo = function () {
   return 'test';
 };
       `,
@@ -193,7 +193,7 @@ const myObj = {
     {
       filename: 'test.ts',
       code: `
-() => function(): void {};
+() => function (): void {};
       `,
       options: [{ allowHigherOrderFunctions: true }],
     },
@@ -210,7 +210,7 @@ const myObj = {
       filename: 'test.ts',
       code: `
 () => {
-  return function(): void {};
+  return function (): void {};
 };
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -228,7 +228,7 @@ function fn() {
       filename: 'test.ts',
       code: `
 function fn() {
-  return function(): void {};
+  return function (): void {};
 }
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -324,7 +324,7 @@ foo({
   },
 });
 foo({
-  meth: function() {
+  meth: function () {
     return 1;
   },
 });
@@ -410,7 +410,7 @@ function test() {
     {
       filename: 'test.ts',
       code: `
-var fn = function() {
+var fn = function () {
   return 1;
 };
       `,
@@ -420,7 +420,7 @@ var fn = function() {
           line: 2,
           endLine: 2,
           column: 10,
-          endColumn: 20,
+          endColumn: 21,
         },
       ],
     },
@@ -522,7 +522,7 @@ function test() {
     },
     {
       filename: 'test.ts',
-      code: 'const foo = function() {};',
+      code: 'const foo = function () {};',
       options: [{ allowExpressions: true }],
       errors: [
         {
@@ -530,7 +530,7 @@ function test() {
           line: 1,
           endLine: 1,
           column: 13,
-          endColumn: 23,
+          endColumn: 24,
         },
       ],
     },
@@ -550,7 +550,7 @@ function test() {
     },
     {
       filename: 'test.ts',
-      code: 'export default function() {}',
+      code: 'export default function () {}',
       options: [{ allowExpressions: true }],
       errors: [
         {
@@ -558,7 +558,7 @@ function test() {
           line: 1,
           endLine: 1,
           column: 16,
-          endColumn: 26,
+          endColumn: 27,
         },
       ],
     },
@@ -567,11 +567,11 @@ function test() {
       code: `
 class Foo {
   public a = () => {};
-  public b = function() {};
+  public b = function () {};
   public c = function test() {};
 
   static d = () => {};
-  static e = function() {};
+  static e = function () {};
 }
       `,
       options: [{ allowExpressions: true }],
@@ -588,7 +588,7 @@ class Foo {
           line: 4,
           endLine: 4,
           column: 14,
-          endColumn: 24,
+          endColumn: 25,
         },
         {
           messageId: 'missingReturnType',
@@ -609,7 +609,7 @@ class Foo {
           line: 8,
           endLine: 8,
           column: 14,
-          endColumn: 24,
+          endColumn: 25,
         },
       ],
     },
@@ -630,7 +630,7 @@ class Foo {
     {
       filename: 'test.ts',
       code: `
-var funcExpr = function() {
+var funcExpr = function () {
   return 'test';
 };
       `,
@@ -641,7 +641,7 @@ var funcExpr = function() {
           line: 2,
           endLine: 2,
           column: 16,
-          endColumn: 26,
+          endColumn: 27,
         },
       ],
     },
@@ -714,7 +714,7 @@ const x: Foo = {
     },
     {
       filename: 'test.ts',
-      code: '() => function() {};',
+      code: '() => function () {};',
       options: [{ allowHigherOrderFunctions: true }],
       errors: [
         {
@@ -722,7 +722,7 @@ const x: Foo = {
           line: 1,
           endLine: 1,
           column: 7,
-          endColumn: 17,
+          endColumn: 18,
         },
       ],
     },
@@ -748,7 +748,7 @@ const x: Foo = {
       filename: 'test.ts',
       code: `
 () => {
-  return function() {};
+  return function () {};
 };
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -758,7 +758,7 @@ const x: Foo = {
           line: 3,
           endLine: 3,
           column: 10,
-          endColumn: 20,
+          endColumn: 21,
         },
       ],
     },
@@ -784,7 +784,7 @@ function fn() {
       filename: 'test.ts',
       code: `
 function fn() {
-  return function() {};
+  return function () {};
 }
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -794,7 +794,7 @@ function fn() {
           line: 3,
           endLine: 3,
           column: 10,
-          endColumn: 20,
+          endColumn: 21,
         },
       ],
     },
@@ -955,7 +955,7 @@ foo({
   },
 });
 foo({
-  meth: function() {
+  meth: function () {
     return 1;
   },
 });
@@ -983,7 +983,7 @@ foo({
           line: 9,
           endLine: 9,
           column: 9,
-          endColumn: 19,
+          endColumn: 20,
         },
         {
           messageId: 'missingReturnType',
diff --git a/packages/eslint-plugin/tests/rules/explicit-module-boundary-types.test.ts b/packages/eslint-plugin/tests/rules/explicit-module-boundary-types.test.ts
index 5d63e8e1036..4d20b7b9a3f 100644
--- a/packages/eslint-plugin/tests/rules/explicit-module-boundary-types.test.ts
+++ b/packages/eslint-plugin/tests/rules/explicit-module-boundary-types.test.ts
@@ -23,7 +23,7 @@ export function test(): void {
     },
     {
       code: `
-export var fn = function(): number {
+export var fn = function (): number {
   return 1;
 };
       `,
@@ -105,7 +105,7 @@ export var arrowFn: Foo = () => 'test';
     },
     {
       code: `
-export var funcExpr: Foo = function() {
+export var funcExpr: Foo = function () {
   return 'test';
 };
       `,
@@ -176,7 +176,7 @@ export default () => (): void => {};
     },
     {
       code: `
-export default () => function(): void {};
+export default () => function (): void {};
       `,
       options: [{ allowHigherOrderFunctions: true }],
     },
@@ -191,7 +191,7 @@ export default () => {
     {
       code: `
 export default () => {
-  return function(): void {};
+  return function (): void {};
 };
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -207,7 +207,7 @@ export function fn() {
     {
       code: `
 export function fn() {
-  return function(): void {};
+  return function (): void {};
 }
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -304,7 +304,7 @@ export class Test {
     {
       code: `
         export function foo(outer: string) {
-          return function(inner: string): void {};
+          return function (inner: string): void {};
         }
       `,
       options: [
@@ -331,7 +331,7 @@ export class Test {
     {
       code: `
 export const Foo: FC = () => (
-  <div a={e => {}} b={function(e) {}} c={function foo(e) {}}></div>
+  <div a={e => {}} b={function (e) {}} c={function foo(e) {}}></div>
 );
       `,
       parserOptions: {
@@ -341,7 +341,7 @@ export const Foo: FC = () => (
     {
       code: `
 export const Foo: JSX.Element = (
-  <div a={e => {}} b={function(e) {}} c={function foo(e) {}}></div>
+  <div a={e => {}} b={function (e) {}} c={function foo(e) {}}></div>
 );
       `,
       parserOptions: {
@@ -473,7 +473,7 @@ export function test() {
     },
     {
       code: `
-export var fn = function() {
+export var fn = function () {
   return 1;
 };
       `,
@@ -483,7 +483,7 @@ export var fn = function() {
           line: 2,
           endLine: 2,
           column: 17,
-          endColumn: 27,
+          endColumn: 28,
         },
       ],
     },
@@ -560,11 +560,11 @@ export class Test {
       code: `
 export class Foo {
   public a = () => {};
-  public b = function() {};
+  public b = function () {};
   public c = function test() {};
 
   static d = () => {};
-  static e = function() {};
+  static e = function () {};
 }
       `,
       errors: [
@@ -580,7 +580,7 @@ export class Foo {
           line: 4,
           endLine: 4,
           column: 14,
-          endColumn: 24,
+          endColumn: 25,
         },
         {
           messageId: 'missingReturnType',
@@ -601,7 +601,7 @@ export class Foo {
           line: 8,
           endLine: 8,
           column: 14,
-          endColumn: 24,
+          endColumn: 25,
         },
       ],
     },
@@ -639,7 +639,7 @@ export class Foo {
     },
     {
       code: `
-export var funcExpr = function() {
+export var funcExpr = function () {
   return 'test';
 };
       `,
@@ -650,7 +650,7 @@ export var funcExpr = function() {
           line: 2,
           endLine: 2,
           column: 23,
-          endColumn: 33,
+          endColumn: 34,
         },
       ],
     },
@@ -717,7 +717,7 @@ export const x: Foo = {
       ],
     },
     {
-      code: 'export default () => function() {};',
+      code: 'export default () => function () {};',
       options: [{ allowHigherOrderFunctions: true }],
       errors: [
         {
@@ -725,7 +725,7 @@ export const x: Foo = {
           line: 1,
           endLine: 1,
           column: 22,
-          endColumn: 32,
+          endColumn: 33,
         },
       ],
     },
@@ -749,7 +749,7 @@ export default () => {
     {
       code: `
 export default () => {
-  return function() {};
+  return function () {};
 };
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -759,7 +759,7 @@ export default () => {
           line: 3,
           endLine: 3,
           column: 10,
-          endColumn: 20,
+          endColumn: 21,
         },
       ],
     },
@@ -783,7 +783,7 @@ export function fn() {
     {
       code: `
 export function fn() {
-  return function() {};
+  return function () {};
 }
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -793,7 +793,7 @@ export function fn() {
           line: 3,
           endLine: 3,
           column: 10,
-          endColumn: 20,
+          endColumn: 21,
         },
       ],
     },
@@ -985,7 +985,7 @@ export function fn(test): string {
     {
       code: `
         export function foo(outer) {
-          return function(inner) {};
+          return function (inner) {};
         }
       `,
       options: [{ allowHigherOrderFunctions: true }],
@@ -1221,7 +1221,7 @@ export default Foo;
     {
       code: `
 class Foo {
-  bool = function(arg) {
+  bool = function (arg) {
     return arg;
   };
 }
@@ -1242,7 +1242,7 @@ export default Foo;
     {
       code: `
 class Foo {
-  bool = function(arg) {
+  bool = function (arg) {
     return arg;
   };
 }
diff --git a/packages/eslint-plugin/tests/rules/init-declarations.test.ts b/packages/eslint-plugin/tests/rules/init-declarations.test.ts
index 6f4c8f75ebb..1d5dc73655f 100644
--- a/packages/eslint-plugin/tests/rules/init-declarations.test.ts
+++ b/packages/eslint-plugin/tests/rules/init-declarations.test.ts
@@ -22,7 +22,7 @@ function foo() {
   var bar = [];
 }
     `,
-    'var fn = function() {};',
+    'var fn = function () {};',
     'var foo = (bar = 2);',
     'for (var i = 0; i < 1; i++) {}',
     `
@@ -245,7 +245,7 @@ function foo() {
     },
     {
       code: `
-var bar: string = function(): string {
+var bar: string = function (): string {
   return 'string';
 };
       `,
@@ -253,7 +253,7 @@ var bar: string = function(): string {
     },
     {
       code: `
-var bar: string = function(arg1: stirng): string {
+var bar: string = function (arg1: stirng): string {
   return 'string';
 };
       `,
@@ -645,7 +645,7 @@ function foo() {
       ],
     },
     {
-      code: 'let arr: string = function() {};',
+      code: 'let arr: string = function () {};',
       options: ['never'],
       errors: [
         {
diff --git a/packages/eslint-plugin/tests/rules/method-signature-style.test.ts b/packages/eslint-plugin/tests/rules/method-signature-style.test.ts
index 62383014082..3f125b33cdf 100644
--- a/packages/eslint-plugin/tests/rules/method-signature-style.test.ts
+++ b/packages/eslint-plugin/tests/rules/method-signature-style.test.ts
@@ -27,8 +27,7 @@ interface Test {
   ['f']: <T extends {}>(a: T, b: T) => T;
 }
     `,
-    // TODO - requires prettier2 to format correctly
-    noFormat`
+    `
 interface Test {
   'f!': </* a */>(/* b */ x: any /* c */) => void;
 }
diff --git a/packages/eslint-plugin/tests/rules/no-explicit-any.test.ts b/packages/eslint-plugin/tests/rules/no-explicit-any.test.ts
index 1a5b9c5778c..2694fdbf104 100644
--- a/packages/eslint-plugin/tests/rules/no-explicit-any.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-explicit-any.test.ts
@@ -147,7 +147,7 @@ type obj = {
       options: [{ ignoreRestArgs: true }],
     },
     {
-      code: 'const bar1 = function(...args: any[]) {};',
+      code: 'const bar1 = function (...args: any[]) {};',
       options: [{ ignoreRestArgs: true }],
     },
     {
@@ -159,7 +159,7 @@ type obj = {
       options: [{ ignoreRestArgs: true }],
     },
     {
-      code: 'const bar2 = function(...args: readonly any[]) {};',
+      code: 'const bar2 = function (...args: readonly any[]) {};',
       options: [{ ignoreRestArgs: true }],
     },
     {
@@ -171,7 +171,7 @@ type obj = {
       options: [{ ignoreRestArgs: true }],
     },
     {
-      code: 'const bar3 = function(...args: Array<any>) {};',
+      code: 'const bar3 = function (...args: Array<any>) {};',
       options: [{ ignoreRestArgs: true }],
     },
     {
@@ -183,7 +183,7 @@ type obj = {
       options: [{ ignoreRestArgs: true }],
     },
     {
-      code: 'const bar4 = function(...args: ReadonlyArray<any>) {};',
+      code: 'const bar4 = function (...args: ReadonlyArray<any>) {};',
       options: [{ ignoreRestArgs: true }],
     },
     {
diff --git a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
index f6601a0613a..e5c0ea5210f 100644
--- a/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-floating-promises.test.ts
@@ -368,7 +368,7 @@ async function test() {
       code: `
         const foo = () =>
           new Promise(res => {
-            (async function() {
+            (async function () {
               await res(1);
             })();
           });
@@ -377,7 +377,7 @@ async function test() {
     },
     {
       code: `
-        (async function() {
+        (async function () {
           await res(1);
         })();
       `,
@@ -826,7 +826,7 @@ async function test() {
       code: `
         const foo = () =>
           new Promise(res => {
-            (async function() {
+            (async function () {
               await res(1);
             })();
           });
@@ -840,7 +840,7 @@ async function test() {
     },
     {
       code: `
-        (async function() {
+        (async function () {
           await res(1);
         })();
       `,
@@ -853,7 +853,7 @@ async function test() {
     },
     {
       code: `
-        (async function() {
+        (async function () {
           Promise.resolve();
         })();
       `,
@@ -867,7 +867,7 @@ async function test() {
     },
     {
       code: `
-        (async function() {
+        (async function () {
           const promiseIntersection: Promise<number> & number;
           promiseIntersection;
           promiseIntersection.then(() => {});
diff --git a/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts b/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts
index 521f838f06f..353a6300b45 100644
--- a/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-implied-eval.test.ts
@@ -18,7 +18,7 @@ ruleTester.run('no-implied-eval', rule, {
     'foo.execScript(null);',
     'foo.setTimeout(null);',
     'foo();',
-    '(function() {})();',
+    '(function () {})();',
 
     'setTimeout(() => {}, 0);',
     'window.setTimeout(() => {}, 0);',
@@ -45,7 +45,7 @@ setImmediate(foo);
 execScript(foo);
     `,
     `
-const foo = function() {};
+const foo = function () {};
 
 setTimeout(foo, 0);
 setInterval(foo, 0);
@@ -72,7 +72,7 @@ execScript(foo.fn);
     `,
     `
 const foo = {
-  fn: function() {},
+  fn: function () {},
 };
 
 setTimeout(foo.fn, 0);
@@ -166,8 +166,8 @@ setImmediate(foo());
 execScript(foo());
     `,
     `
-const foo = function() {
-  return function() {
+const foo = function () {
+  return function () {
     return '';
   };
 };
@@ -368,7 +368,7 @@ execScript(foo);
     },
     {
       code: `
-const foo = function() {
+const foo = function () {
   return 'x + 1';
 };
 
@@ -402,7 +402,7 @@ execScript(foo());
     },
     {
       code: `
-const foo = function() {
+const foo = function () {
   return () => 'x + 1';
 };
 
@@ -436,7 +436,7 @@ execScript(foo()());
     },
     {
       code: `
-const fn = function() {};
+const fn = function () {};
 
 setTimeout(fn + '', 0);
 setInterval(fn + '', 0);
diff --git a/packages/eslint-plugin/tests/rules/no-inferrable-types.test.ts b/packages/eslint-plugin/tests/rules/no-inferrable-types.test.ts
index b87e778d508..0f7bb141f1b 100644
--- a/packages/eslint-plugin/tests/rules/no-inferrable-types.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-inferrable-types.test.ts
@@ -103,7 +103,7 @@ ruleTester.run('no-inferrable-types', rule, {
     ...validTestCases,
 
     "const fn = (a = 5, b = true, c = 'foo') => {};",
-    "const fn = function(a = 5, b = true, c = 'foo') {};",
+    "const fn = function (a = 5, b = true, c = 'foo') {};",
     "function fn(a = 5, b = true, c = 'foo') {}",
     'function fn(a: number, b: boolean, c: string) {}',
 
@@ -121,7 +121,7 @@ class Foo {
     `,
 
     'const a: any = 5;',
-    "const fn = function(a: any = 5, b: any = true, c: any = 'foo') {};",
+    "const fn = function (a: any = 5, b: any = true, c: any = 'foo') {};",
 
     {
       code:
@@ -135,7 +135,7 @@ class Foo {
     },
     {
       code:
-        "const fn = function(a: number = 5, b: boolean = true, c: string = 'foo') {};",
+        "const fn = function (a: number = 5, b: boolean = true, c: string = 'foo') {};",
       options: [{ ignoreParameters: true }],
     },
     {
diff --git a/packages/eslint-plugin/tests/rules/no-invalid-this.test.ts b/packages/eslint-plugin/tests/rules/no-invalid-this.test.ts
index 93701a2dc32..f3d339fe63e 100644
--- a/packages/eslint-plugin/tests/rules/no-invalid-this.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-invalid-this.test.ts
@@ -18,7 +18,7 @@ ruleTester.run('no-invalid-this', rule, {
   valid: [
     `
 describe('foo', () => {
-  it('does something', function(this: Mocha.Context) {
+  it('does something', function (this: Mocha.Context) {
     this.timeout(100);
     // done
   });
@@ -38,7 +38,7 @@ function foo(this: prop) {
 }
     `,
     `
-z(function(x, this: context) {
+z(function (x, this: context) {
   console.log(x, this);
 });
     `,
@@ -56,7 +56,7 @@ function foo() {
     // https://github.com/eslint/eslint/issues/6824
 
     `
-var Ctor = function() {
+var Ctor = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -113,7 +113,7 @@ class A {
     {
       code: `
 var obj = {
-  foo: function() {
+  foo: function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -135,7 +135,7 @@ var obj = {
 var obj = {
   foo:
     foo ||
-    function() {
+    function () {
       console.log(this);
       z(x => console.log(x, this));
     },
@@ -147,7 +147,7 @@ var obj = {
 var obj = {
   foo: hasNative
     ? foo
-    : function() {
+    : function () {
         console.log(this);
         z(x => console.log(x, this));
       },
@@ -157,8 +157,8 @@ var obj = {
     {
       code: `
 var obj = {
-  foo: (function() {
-    return function() {
+  foo: (function () {
+    return function () {
       console.log(this);
       z(x => console.log(x, this));
     };
@@ -169,7 +169,7 @@ var obj = {
     {
       code: `
 Object.defineProperty(obj, 'foo', {
-  value: function() {
+  value: function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -180,7 +180,7 @@ Object.defineProperty(obj, 'foo', {
       code: `
 Object.defineProperties(obj, {
   foo: {
-    value: function() {
+    value: function () {
       console.log(this);
       z(x => console.log(x, this));
     },
@@ -192,7 +192,7 @@ Object.defineProperties(obj, {
     // Assigns to a property.
     {
       code: `
-obj.foo = function() {
+obj.foo = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -202,7 +202,7 @@ obj.foo = function() {
       code: `
 obj.foo =
   foo ||
-  function() {
+  function () {
     console.log(this);
     z(x => console.log(x, this));
   };
@@ -212,7 +212,7 @@ obj.foo =
       code: `
 obj.foo = foo
   ? bar
-  : function() {
+  : function () {
       console.log(this);
       z(x => console.log(x, this));
     };
@@ -220,8 +220,8 @@ obj.foo = foo
     },
     {
       code: `
-obj.foo = (function() {
-  return function() {
+obj.foo = (function () {
+  return function () {
     console.log(this);
     z(x => console.log(x, this));
   };
@@ -231,7 +231,7 @@ obj.foo = (function() {
     {
       code: `
 obj.foo = (() =>
-  function() {
+  function () {
     console.log(this);
     z(x => console.log(x, this));
   })();
@@ -240,20 +240,20 @@ obj.foo = (() =>
 
     // Bind/Call/Apply
     `
-(function() {
+(function () {
   console.log(this);
   z(x => console.log(x, this));
 }.call(obj));
     `,
     `
-var foo = function() {
+var foo = function () {
   console.log(this);
   z(x => console.log(x, this));
 }.bind(obj);
     `,
     `
 Reflect.apply(
-  function() {
+  function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -262,7 +262,7 @@ Reflect.apply(
 );
     `,
     `
-(function() {
+(function () {
   console.log(this);
   z(x => console.log(x, this));
 }.apply(obj));
@@ -283,7 +283,7 @@ class A {
     `
 Array.from(
   [],
-  function() {
+  function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -292,49 +292,49 @@ Array.from(
     `,
 
     `
-foo.every(function() {
+foo.every(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
     `,
 
     `
-foo.filter(function() {
+foo.filter(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
     `,
 
     `
-foo.find(function() {
+foo.find(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
     `,
 
     `
-foo.findIndex(function() {
+foo.findIndex(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
     `,
 
     `
-foo.forEach(function() {
+foo.forEach(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
     `,
 
     `
-foo.map(function() {
+foo.map(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
     `,
 
     `
-foo.some(function() {
+foo.some(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, obj);
@@ -351,7 +351,7 @@ foo.some(function() {
 
     `
 foo(
-  /* @this Obj */ function() {
+  /* @this Obj */ function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -370,7 +370,7 @@ function foo() {
     `,
 
     `
-Ctor = function() {
+Ctor = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -378,7 +378,7 @@ Ctor = function() {
 
     `
 function foo(
-  Ctor = function() {
+  Ctor = function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -387,7 +387,7 @@ function foo(
 
     `
 [
-  obj.method = function() {
+  obj.method = function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -441,7 +441,7 @@ z(x => console.log(x, this));
     // IIFE.
     {
       code: `
-(function() {
+(function () {
   console.log(this);
   z(x => console.log(x, this));
 })();
@@ -508,7 +508,7 @@ function Foo() {
     },
     {
       code: `
-return function() {
+return function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -520,7 +520,7 @@ return function() {
     },
     {
       code: `
-var foo = function() {
+var foo = function () {
   console.log(this);
   z(x => console.log(x, this));
 }.bar(obj);
@@ -533,7 +533,7 @@ var foo = function() {
     {
       code: `
 var obj = {
-  foo: function() {
+  foo: function () {
     function foo() {
       console.log(this);
       z(x => console.log(x, this));
@@ -563,8 +563,8 @@ var obj = {
     {
       code: `
 var obj = {
-  foo: function() {
-    return function() {
+  foo: function () {
+    return function () {
       console.log(this);
       z(x => console.log(x, this));
     };
@@ -577,9 +577,9 @@ var obj = {
     {
       code: `
 var obj = {
-  foo: function() {
+  foo: function () {
     'use strict';
-    return function() {
+    return function () {
       console.log(this);
       z(x => console.log(x, this));
     };
@@ -591,8 +591,8 @@ var obj = {
     },
     {
       code: `
-obj.foo = function() {
-  return function() {
+obj.foo = function () {
+  return function () {
     console.log(this);
     z(x => console.log(x, this));
   };
@@ -603,9 +603,9 @@ obj.foo = function() {
     },
     {
       code: `
-obj.foo = function() {
+obj.foo = function () {
   'use strict';
-  return function() {
+  return function () {
     console.log(this);
     z(x => console.log(x, this));
   };
@@ -618,7 +618,7 @@ obj.foo = function() {
       code: `
 class A {
   foo() {
-    return function() {
+    return function () {
       console.log(this);
       z(x => console.log(x, this));
     };
@@ -633,7 +633,7 @@ class A {
 
     {
       code: `
-obj.foo = (function() {
+obj.foo = (function () {
   return () => {
     console.log(this);
     z(x => console.log(x, this));
@@ -657,7 +657,7 @@ obj.foo = (() => () => {
 
     {
       code: `
-var foo = function() {
+var foo = function () {
   console.log(this);
   z(x => console.log(x, this));
 }.bind(null);
@@ -668,7 +668,7 @@ var foo = function() {
 
     {
       code: `
-(function() {
+(function () {
   console.log(this);
   z(x => console.log(x, this));
 }.call(undefined));
@@ -679,7 +679,7 @@ var foo = function() {
 
     {
       code: `
-(function() {
+(function () {
   console.log(this);
   z(x => console.log(x, this));
 }.apply(void 0));
@@ -691,7 +691,7 @@ var foo = function() {
     // Array methods.
     {
       code: `
-Array.from([], function() {
+Array.from([], function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -701,7 +701,7 @@ Array.from([], function() {
     },
     {
       code: `
-foo.every(function() {
+foo.every(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -711,7 +711,7 @@ foo.every(function() {
     },
     {
       code: `
-foo.filter(function() {
+foo.filter(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -721,7 +721,7 @@ foo.filter(function() {
     },
     {
       code: `
-foo.find(function() {
+foo.find(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -731,7 +731,7 @@ foo.find(function() {
     },
     {
       code: `
-foo.findIndex(function() {
+foo.findIndex(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -741,7 +741,7 @@ foo.findIndex(function() {
     },
     {
       code: `
-foo.forEach(function() {
+foo.forEach(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -751,7 +751,7 @@ foo.forEach(function() {
     },
     {
       code: `
-foo.map(function() {
+foo.map(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -761,7 +761,7 @@ foo.map(function() {
     },
     {
       code: `
-foo.some(function() {
+foo.some(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -772,7 +772,7 @@ foo.some(function() {
 
     {
       code: `
-foo.forEach(function() {
+foo.forEach(function () {
   console.log(this);
   z(x => console.log(x, this));
 }, null);
@@ -795,7 +795,7 @@ foo.forEach(function() {
     },
     {
       code: `
-/** @this Obj */ foo(function() {
+/** @this Obj */ foo(function () {
   console.log(this);
   z(x => console.log(x, this));
 });
@@ -806,7 +806,7 @@ foo.forEach(function() {
 
     {
       code: `
-var Ctor = function() {
+var Ctor = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -817,7 +817,7 @@ var Ctor = function() {
     },
     {
       code: `
-var func = function() {
+var func = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -827,7 +827,7 @@ var func = function() {
     },
     {
       code: `
-var func = function() {
+var func = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -839,7 +839,7 @@ var func = function() {
 
     {
       code: `
-Ctor = function() {
+Ctor = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -850,7 +850,7 @@ Ctor = function() {
     },
     {
       code: `
-func = function() {
+func = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -860,7 +860,7 @@ func = function() {
     },
     {
       code: `
-func = function() {
+func = function () {
   console.log(this);
   z(x => console.log(x, this));
 };
@@ -873,7 +873,7 @@ func = function() {
     {
       code: `
 function foo(
-  func = function() {
+  func = function () {
     console.log(this);
     z(x => console.log(x, this));
   },
@@ -886,7 +886,7 @@ function foo(
     {
       code: `
 [
-  func = function() {
+  func = function () {
     console.log(this);
     z(x => console.log(x, this));
   },
diff --git a/packages/eslint-plugin/tests/rules/no-unused-vars.test.ts b/packages/eslint-plugin/tests/rules/no-unused-vars.test.ts
index f59cb588425..6b0d7f4148b 100644
--- a/packages/eslint-plugin/tests/rules/no-unused-vars.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-unused-vars.test.ts
@@ -135,7 +135,7 @@ bar<Foo>();
     `,
     `
 import { Foo } from 'foo';
-const bar = function<T>() {};
+const bar = function <T>() {};
 bar<Foo>();
     `,
     `
diff --git a/packages/eslint-plugin/tests/rules/no-use-before-define.test.ts b/packages/eslint-plugin/tests/rules/no-use-before-define.test.ts
index dbbfcd61f5a..aa09db0f29f 100644
--- a/packages/eslint-plugin/tests/rules/no-use-before-define.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-use-before-define.test.ts
@@ -97,7 +97,7 @@ function foo() {
 }
     `,
     `
-var foo = function() {
+var foo = function () {
   foo();
 };
     `,
@@ -154,7 +154,7 @@ switch (foo) {
       code: `
 a();
 {
-  let a = function() {};
+  let a = function () {};
 }
       `,
       parserOptions,
@@ -355,7 +355,7 @@ var a = 19;
     {
       code: `
 a();
-var a = function() {};
+var a = function () {};
       `,
       errors: [
         {
@@ -403,7 +403,7 @@ function a() {
     {
       code: `
 a();
-var a = function() {};
+var a = function () {};
       `,
       options: ['nofunc'],
       errors: [
@@ -644,7 +644,7 @@ if (true) {
     {
       code: `
 a();
-var a = function() {};
+var a = function () {};
       `,
       options: [{ functions: false, classes: false }],
       errors: [
diff --git a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
index 43ecdb03fe8..c1602f01913 100644
--- a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
@@ -14,7 +14,7 @@ const ruleTester = new RuleTester({
 ruleTester.run('prefer-readonly', rule, {
   valid: [
     'function ignore() {}',
-    'const ignore = function() {};',
+    'const ignore = function () {};',
     'const ignore = () => {};',
     `
       const container = { member: true };
diff --git a/packages/eslint-plugin/tests/rules/promise-function-async.test.ts b/packages/eslint-plugin/tests/rules/promise-function-async.test.ts
index d4da6e3b66c..47b5b6221d6 100644
--- a/packages/eslint-plugin/tests/rules/promise-function-async.test.ts
+++ b/packages/eslint-plugin/tests/rules/promise-function-async.test.ts
@@ -24,12 +24,12 @@ function nonAsyncNonPromiseFunctionDeclaration(n: number) {
 }
     `,
     `
-const asyncPromiseFunctionExpressionA = async function(p: Promise<void>) {
+const asyncPromiseFunctionExpressionA = async function (p: Promise<void>) {
   return p;
 };
     `,
     `
-const asyncPromiseFunctionExpressionB = async function() {
+const asyncPromiseFunctionExpressionB = async function () {
   return new Promise<void>();
 };
     `,
@@ -182,7 +182,7 @@ function returnsUnknown(): unknown {
     },
     {
       code: `
-const nonAsyncPromiseFunctionExpressionA = function(p: Promise<void>) {
+const nonAsyncPromiseFunctionExpressionA = function (p: Promise<void>) {
   return p;
 };
       `,
@@ -194,7 +194,7 @@ const nonAsyncPromiseFunctionExpressionA = function(p: Promise<void>) {
     },
     {
       code: `
-const nonAsyncPromiseFunctionExpressionB = function() {
+const nonAsyncPromiseFunctionExpressionB = function () {
   return new Promise<void>();
 };
       `,
@@ -273,7 +273,7 @@ class Test {
     },
     {
       code: `
-const nonAsyncPromiseFunctionExpression = function(p: Promise<void>) {
+const nonAsyncPromiseFunctionExpression = function (p: Promise<void>) {
   return p;
 };
 
@@ -311,7 +311,7 @@ class Test {
     },
     {
       code: `
-const nonAsyncPromiseFunctionExpression = function(p: Promise<void>) {
+const nonAsyncPromiseFunctionExpression = function (p: Promise<void>) {
   return p;
 };
 
@@ -349,7 +349,7 @@ class Test {
     },
     {
       code: `
-const nonAsyncPromiseFunctionExpression = function(p: Promise<void>) {
+const nonAsyncPromiseFunctionExpression = function (p: Promise<void>) {
   return p;
 };
 
@@ -387,7 +387,7 @@ class Test {
     },
     {
       code: `
-const nonAsyncPromiseFunctionExpression = function(p: Promise<void>) {
+const nonAsyncPromiseFunctionExpression = function (p: Promise<void>) {
   return p;
 };
 
diff --git a/packages/eslint-plugin/tests/rules/require-await.test.ts b/packages/eslint-plugin/tests/rules/require-await.test.ts
index 05c4bf739b9..add1855f36b 100644
--- a/packages/eslint-plugin/tests/rules/require-await.test.ts
+++ b/packages/eslint-plugin/tests/rules/require-await.test.ts
@@ -22,7 +22,7 @@ function numberOne(): number {
     `,
     // Non-async function expression
     `
-const numberOne = function(): number {
+const numberOne = function (): number {
   return 1;
 };
     `,
@@ -57,7 +57,7 @@ async function numberOne(): Promise<number> {
     `,
     // Async function expression with await
     `
-const numberOne = async function(): Promise<number> {
+const numberOne = async function (): Promise<number> {
   return await 1;
 };
     `,
@@ -77,7 +77,7 @@ async function numberOne(): Promise<number> {
     `,
     // Async function expression with promise return
     `
-const numberOne = async function(): Promise<number> {
+const numberOne = async function (): Promise<number> {
   return Promise.resolve(1);
 };
     `,
@@ -100,17 +100,17 @@ async function getAsyncNumber(x: number): Promise<number> {
     `,
     // Async function expression with async function return
     `
-const numberOne = async function(): Promise<number> {
+const numberOne = async function (): Promise<number> {
   return getAsyncNumber(1);
 };
-const getAsyncNumber = async function(x: number): Promise<number> {
+const getAsyncNumber = async function (x: number): Promise<number> {
   return Promise.resolve(x);
 };
     `,
     // Async arrow function with async function return (concise-body)
     `
 const numberOne = async (): Promise<number> => getAsyncNumber(1);
-const getAsyncNumber = async function(x: number): Promise<number> {
+const getAsyncNumber = async function (x: number): Promise<number> {
   return Promise.resolve(x);
 };
     `,
@@ -119,7 +119,7 @@ const getAsyncNumber = async function(x: number): Promise<number> {
 const numberOne = async (): Promise<number> => {
   return getAsyncNumber(1);
 };
-const getAsyncNumber = async function(x: number): Promise<number> {
+const getAsyncNumber = async function (x: number): Promise<number> {
   return Promise.resolve(x);
 };
     `,
@@ -161,7 +161,7 @@ async function* test1() {
   yield* asyncGenerator();
 }
     `,
-    'const foo: () => void = async function*() {};',
+    'const foo: () => void = async function* () {};',
     `
 async function* foo(): Promise<string> {
   return new Promise(res => res(\`hello\`));
@@ -189,7 +189,7 @@ async function numberOne(): Promise<number> {
     {
       // Async function expression with no await
       code: `
-const numberOne = async function(): Promise<number> {
+const numberOne = async function (): Promise<number> {
   return 1;
 };
       `,
@@ -264,7 +264,7 @@ async function* foo() {
     },
     {
       code: `
-const foo = async function*() {
+const foo = async function* () {
   console.log('bar');
 };
       `,
@@ -322,7 +322,7 @@ async function foo() {
 }
     `,
     `
-(async function() {
+(async function () {
   await doSomething();
 });
     `,
@@ -403,7 +403,7 @@ for await (let num of asyncIterable) {
     },
     {
       code: `
-        (async function() {
+        (async function () {
           doSomething();
         });
       `,
diff --git a/packages/eslint-plugin/tests/rules/typedef.test.ts b/packages/eslint-plugin/tests/rules/typedef.test.ts
index d6b37c811ed..e624670d206 100644
--- a/packages/eslint-plugin/tests/rules/typedef.test.ts
+++ b/packages/eslint-plugin/tests/rules/typedef.test.ts
@@ -378,7 +378,7 @@ ruleTester.run('typedef', rule, {
     },
     // variable declaration ignore function
     {
-      code: 'const foo = function(): void {};',
+      code: 'const foo = function (): void {};',
       options: [
         {
           variableDeclaration: true,
@@ -405,7 +405,7 @@ ruleTester.run('typedef', rule, {
       ],
     },
     {
-      code: 'const foo: () => void = function(): void {};',
+      code: 'const foo: () => void = function (): void {};',
       options: [
         {
           variableDeclaration: true,
@@ -417,7 +417,7 @@ ruleTester.run('typedef', rule, {
       code: `
 class Foo {
   a = (): void => {};
-  b = function(): void {};
+  b = function (): void {};
 }
       `,
       options: [
@@ -831,7 +831,7 @@ class Foo {
       ],
     },
     {
-      code: 'const foo = function(): void {};',
+      code: 'const foo = function (): void {};',
       errors: [
         {
           messageId: 'expectedTypedefNamed',
@@ -864,7 +864,7 @@ class Foo {
       code: `
 class Foo {
   a = (): void => {};
-  b = function(): void {};
+  b = function (): void {};
 }
       `,
       errors: [
diff --git a/packages/eslint-plugin/tests/rules/unbound-method.test.ts b/packages/eslint-plugin/tests/rules/unbound-method.test.ts
index 20caa1d8b45..12d6486e09f 100644
--- a/packages/eslint-plugin/tests/rules/unbound-method.test.ts
+++ b/packages/eslint-plugin/tests/rules/unbound-method.test.ts
@@ -373,7 +373,7 @@ instance.unbound = x; // THIS SHOULD NOT
     {
       code: `
 class Foo {
-  unbound = function() {};
+  unbound = function () {};
 }
 const unbound = new Foo().unbound;
       `,
diff --git a/packages/eslint-plugin/tests/rules/unified-signatures.test.ts b/packages/eslint-plugin/tests/rules/unified-signatures.test.ts
index 3c109d67a03..ea259aea432 100644
--- a/packages/eslint-plugin/tests/rules/unified-signatures.test.ts
+++ b/packages/eslint-plugin/tests/rules/unified-signatures.test.ts
@@ -131,11 +131,11 @@ export interface Foo {
     `,
     `
 declare module 'foo' {
-  export default function(foo: number): string[];
+  export default function (foo: number): string[];
 }
     `,
     `
-export default function(foo: number): string[];
+export default function (foo: number): string[];
     `,
     // https://github.com/typescript-eslint/typescript-eslint/issues/740
     `
@@ -682,28 +682,28 @@ export function foo(line: number, character?: number): number;
     {
       code: `
 declare module 'foo' {
-  export default function(foo: number): string[];
-  export default function(foo: number, bar?: string): string[];
+  export default function (foo: number): string[];
+  export default function (foo: number, bar?: string): string[];
 }
       `,
       errors: [
         {
           messageId: 'omittingSingleParameter',
           line: 4,
-          column: 40,
+          column: 41,
         },
       ],
     },
     {
       code: `
-export default function(foo: number): string[];
-export default function(foo: number, bar?: string): string[];
+export default function (foo: number): string[];
+export default function (foo: number, bar?: string): string[];
       `,
       errors: [
         {
           messageId: 'omittingSingleParameter',
           line: 3,
-          column: 38,
+          column: 39,
         },
       ],
     },
diff --git a/packages/parser/src/analyze-scope.ts b/packages/parser/src/analyze-scope.ts
index 4e680373d77..66a2167d41c 100644
--- a/packages/parser/src/analyze-scope.ts
+++ b/packages/parser/src/analyze-scope.ts
@@ -17,7 +17,7 @@ import { visitorKeys as childVisitorKeys } from '@typescript-eslint/typescript-e
 function overrideDefine(
   define: (node: TSESTree.Node, def: TSESLintScope.Definition) => void,
 ) {
-  return function(
+  return function (
     this: TSESLintScope.Scope,
     node: TSESTree.Node,
     definition: TSESLintScope.Definition,
diff --git a/yarn.lock b/yarn.lock
index 04ba7af56f0..1be631b3cbe 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1486,10 +1486,10 @@
   resolved "https://registry.yarnpkg.com/@types/normalize-package-data/-/normalize-package-data-2.4.0.tgz#e486d0d97396d79beedd0a6e33f4534ff6b4973e"
   integrity sha512-f5j5b/Gf71L+dbqxIpQ4Z2WlmI/mPJ0fOkGGmFgtb6sAu97EPczzbS3/tJKxmcYDj55OX6ssqwDAWOHIYDRDGA==
 
-"@types/prettier@^1.18.2":
-  version "1.18.3"
-  resolved "https://registry.yarnpkg.com/@types/prettier/-/prettier-1.18.3.tgz#64ff53329ce16139f17c3db9d3e0487199972cd8"
-  integrity sha512-48rnerQdcZ26odp+HOvDGX8IcUkYOCuMc2BodWYTe956MqkHlOGAG4oFQ83cjZ0a4GAgj7mb4GUClxYd2Hlodg==
+"@types/prettier@^2.0.0":
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/@types/prettier/-/prettier-2.0.0.tgz#dc85454b953178cc6043df5208b9e949b54a3bc4"
+  integrity sha512-/rM+sWiuOZ5dvuVzV37sUuklsbg+JPOP8d+nNFlo2ZtfpzPiPvh1/gc8liWOLBqe+sR+ZM7guPaIcTt6UZTo7Q==
 
 "@types/semver@^6.2.0":
   version "6.2.0"
@@ -6804,10 +6804,10 @@ prelude-ls@~1.1.2:
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
   integrity sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ=
 
-prettier@*, prettier@^1.19.1:
-  version "1.19.1"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.19.1.tgz#f7d7f5ff8a9cd872a7be4ca142095956a60797cb"
-  integrity sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==
+prettier@*, prettier@^2.0.5:
+  version "2.0.5"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.0.5.tgz#d6d56282455243f2f92cc1716692c08aa31522d4"
+  integrity sha512-7PtVymN48hGcO4fGjybyBSIWDsLU4H4XlvOHfq91pz9kkGlonzwTfYkaIEwiRg/dAJF9YlbsduBAgtYLi+8cFg==
 
 pretty-format@^25.1.0:
   version "25.1.0"