diff --git a/package.json b/package.json
index e84440995..1d49ecbba 100644
--- a/package.json
+++ b/package.json
@@ -6,9 +6,10 @@
     "ci:coverage:submit": "node scripts/codecov",
     "ci:lint": "node scripts/run-changed.js ci:lint",
     "ci:test": "node scripts/run-changed.js ci:test",
-    "lint": "pnpm run lint:docs && pnpm run lint:package && node scripts/run-changed.js lint",
-    "lint:docs": "prettier --write README.md",
+    "lint": "pnpm run lint:docs && npm run lint:json && pnpm run lint:package && node scripts/run-changed.js lint",
+    "lint:docs": "prettier --single-quote --write README.md",
     "lint:js": "eslint scripts util",
+    "lint:json": "prettier --single-quote --write tsconfig.*.json codecov.yml pnpm-workspace.yaml",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "preinstall": "node scripts/disallow-npm.js",
     "pub": "node scripts/pub.js",
diff --git a/packages/alias/package.json b/packages/alias/package.json
index c78496ed9..37d0d4e37 100755
--- a/packages/alias/package.json
+++ b/packages/alias/package.json
@@ -22,7 +22,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
+    "lint:js": "eslint --fix --cache src test types --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/alias/tsconfig.json b/packages/alias/tsconfig.json
index 11a2c4d75..eb2531749 100644
--- a/packages/alias/tsconfig.json
+++ b/packages/alias/tsconfig.json
@@ -1,9 +1,5 @@
 {
   "extends": "../../tsconfig.base.json",
-  "compilerOptions": {
-    "lib": ["es6"],
-    "module": "esnext"
-  },
   "include": [
     "src/**/*",
     "types/**/*"
diff --git a/packages/alias/types/index.d.ts b/packages/alias/types/index.d.ts
index 701286855..d826f8f35 100644
--- a/packages/alias/types/index.d.ts
+++ b/packages/alias/types/index.d.ts
@@ -1,35 +1,35 @@
 import { Plugin, ResolveIdResult } from 'rollup';
 
 export interface Alias {
-    find: string | RegExp;
-    replacement: string;
-    customResolver?: ResolverFunction | ResolverObject | null;
+  find: string | RegExp;
+  replacement: string;
+  customResolver?: ResolverFunction | ResolverObject | null;
 }
 
 export type ResolverFunction = (
-    source: string,
-    importer: string | undefined
+  source: string,
+  importer: string | undefined
 ) => Promise<ResolveIdResult> | ResolveIdResult;
 
 export interface ResolverObject {
-    resolveId: ResolverFunction;
+  resolveId: ResolverFunction;
 }
 
 export interface RollupAliasOptions {
-    /**
-     * Instructs the plugin to use an alternative resolving algorithm,
-     * rather than the Rollup's resolver.
-     * @default null
-     */
-    customResolver?: ResolverFunction | ResolverObject | null;
+  /**
+   * Instructs the plugin to use an alternative resolving algorithm,
+   * rather than the Rollup's resolver.
+   * @default null
+   */
+  customResolver?: ResolverFunction | ResolverObject | null;
 
-    /**
-     * Specifies an `Object`, or an `Array` of `Object`,
-     * which defines aliases used to replace values in `import` or `require` statements.
-     * With either format, the order of the entries is important,
-     * in that the first defined rules are applied first.
-     */
-    entries?: readonly Alias[] | { [find: string]: string };
+  /**
+   * Specifies an `Object`, or an `Array` of `Object`,
+   * which defines aliases used to replace values in `import` or `require` statements.
+   * With either format, the order of the entries is important,
+   * in that the first defined rules are applied first.
+   */
+  entries?: readonly Alias[] | { [find: string]: string };
 }
 
 /**
diff --git a/packages/auto-install/tsconfig.json b/packages/auto-install/tsconfig.json
index 11a2c4d75..eb2531749 100644
--- a/packages/auto-install/tsconfig.json
+++ b/packages/auto-install/tsconfig.json
@@ -1,9 +1,5 @@
 {
   "extends": "../../tsconfig.base.json",
-  "compilerOptions": {
-    "lib": ["es6"],
-    "module": "esnext"
-  },
   "include": [
     "src/**/*",
     "types/**/*"
diff --git a/packages/beep/package.json b/packages/beep/package.json
index 1296f8d7a..fac5babf7 100644
--- a/packages/beep/package.json
+++ b/packages/beep/package.json
@@ -21,7 +21,7 @@
     "ci:test": "ava --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache lib test --ext .js,.ts",
+    "lint:js": "eslint --fix --cache lib test types --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "test": "ava"
   },
diff --git a/packages/beep/types/index.d.ts b/packages/beep/types/index.d.ts
index 65cbc60d8..6df01ce2f 100644
--- a/packages/beep/types/index.d.ts
+++ b/packages/beep/types/index.d.ts
@@ -1,6 +1,6 @@
-import { Plugin } from 'rollup';
-
-/**
- * 🍣 A Rollup plugin that beeps when a build ends with errors.
- */
-export default function beep(): Plugin;
+import { Plugin } from 'rollup';
+
+/**
+ * 🍣 A Rollup plugin that beeps when a build ends with errors.
+ */
+export default function beep(): Plugin;
diff --git a/packages/buble/tsconfig.json b/packages/buble/tsconfig.json
index d7cd9de94..eb2531749 100644
--- a/packages/buble/tsconfig.json
+++ b/packages/buble/tsconfig.json
@@ -1,13 +1,7 @@
 {
   "extends": "../../tsconfig.base.json",
-  "compilerOptions": {
-    "lib": ["es6"],
-    "module": "esnext",
-    "allowJs": true
-  },
   "include": [
     "src/**/*",
-    "types/**/*",
-    "typings-test.js"
+    "types/**/*"
   ]
 }
diff --git a/packages/dsv/package.json b/packages/dsv/package.json
index 855bcd1b3..33849d0fb 100755
--- a/packages/dsv/package.json
+++ b/packages/dsv/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/html/package.json b/packages/html/package.json
index b4bb1f14c..b7a17fbfe 100644
--- a/packages/html/package.json
+++ b/packages/html/package.json
@@ -21,7 +21,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write *.md",
-    "lint:js": "eslint --fix --cache lib test",
+    "lint:js": "eslint --fix --cache lib test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prepublishOnly": "pnpm run lint",
     "test": "ava"
diff --git a/packages/image/package.json b/packages/image/package.json
index 5c373209d..c9bbdddec 100644
--- a/packages/image/package.json
+++ b/packages/image/package.json
@@ -22,7 +22,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write *.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/inject/package.json b/packages/inject/package.json
index 5a1b0aa0e..5a7a2ce86 100644
--- a/packages/inject/package.json
+++ b/packages/inject/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose && pnpm run test:ts",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/inject/test/types.ts b/packages/inject/test/types.ts
index 98559de0f..00eec291f 100644
--- a/packages/inject/test/types.ts
+++ b/packages/inject/test/types.ts
@@ -1,24 +1,22 @@
-// @ts-check
-import { dirname } from "path";
+import { RollupOptions } from 'rollup';
 
-import inject, { RollupInjectOptions } from "..";
+import inject from '..';
 
-/** @type {import("rollup").RollupOptions} */
-const config = {
-  input: "main.js",
+const config: RollupOptions = {
+  input: 'main.js',
   output: {
-    file: "bundle.js",
-    format: "iife"
+    file: 'bundle.js',
+    format: 'iife'
   },
   plugins: [
     inject({
-      include: "config.js",
-      exclude: "node_modules/**",
-      Promise: ["es6-promise", "Promise"],
-      $: "jquery",
+      include: 'config.js',
+      exclude: 'node_modules/**',
+      Promise: ['es6-promise', 'Promise'],
+      $: 'jquery',
       modules: {
-        Promise: ["es6-promise", "Promise"],
-        $: "jquery"
+        Promise: ['es6-promise', 'Promise'],
+        $: 'jquery'
       }
     })
   ]
diff --git a/packages/json/package.json b/packages/json/package.json
index 8ee97e5e5..d6784e5c6 100755
--- a/packages/json/package.json
+++ b/packages/json/package.json
@@ -17,9 +17,10 @@
     "ci:lint": "pnpm run build && pnpm run lint",
     "ci:lint:commits": "commitlint --from=${CIRCLE_BRANCH} --to=${CIRCLE_SHA1}",
     "ci:test": "pnpm run test -- --verbose && pnpm run test:ts",
-    "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
+    "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:json && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
     "lint:js": "eslint --fix --cache src test types --ext .js,.ts",
+    "lint:json": "prettier --write \"test/fixtures/!(garbage)/*.json\"",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/json/test/fixtures/array/config.json b/packages/json/test/fixtures/array/config.json
index feb087e74..b5d8bb58d 100755
--- a/packages/json/test/fixtures/array/config.json
+++ b/packages/json/test/fixtures/array/config.json
@@ -1,3 +1 @@
-[
-  1, 2, 3
-]
+[1, 2, 3]
diff --git a/packages/json/test/fixtures/basic/config.json b/packages/json/test/fixtures/basic/config.json
index 5d18e67d2..0a6e8769b 100755
--- a/packages/json/test/fixtures/basic/config.json
+++ b/packages/json/test/fixtures/basic/config.json
@@ -1,3 +1,3 @@
 {
-	"answer": 42
+  "answer": 42
 }
diff --git a/packages/json/test/fixtures/extensionless/config.json b/packages/json/test/fixtures/extensionless/config.json
index 5d18e67d2..0a6e8769b 100755
--- a/packages/json/test/fixtures/extensionless/config.json
+++ b/packages/json/test/fixtures/extensionless/config.json
@@ -1,3 +1,3 @@
 {
-	"answer": 42
+  "answer": 42
 }
diff --git a/packages/json/test/fixtures/extensionless/dir/index.json b/packages/json/test/fixtures/extensionless/dir/index.json
index aac70eac2..6092acb91 100755
--- a/packages/json/test/fixtures/extensionless/dir/index.json
+++ b/packages/json/test/fixtures/extensionless/dir/index.json
@@ -1,3 +1,3 @@
 {
-	"Are extensionless imports and /index resolutions a good idea?": "No."
+  "Are extensionless imports and /index resolutions a good idea?": "No."
 }
diff --git a/packages/json/test/fixtures/named/package.json b/packages/json/test/fixtures/named/package.json
index 595e4d544..6a0a1011d 100755
--- a/packages/json/test/fixtures/named/package.json
+++ b/packages/json/test/fixtures/named/package.json
@@ -1,4 +1,4 @@
 {
-	"name": "this-should-be-excluded",
-	"version": "1.33.7"
+  "name": "this-should-be-excluded",
+  "version": "1.33.7"
 }
diff --git a/packages/legacy/package.json b/packages/legacy/package.json
index 00571e3a6..36761db09 100644
--- a/packages/legacy/package.json
+++ b/packages/legacy/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/multi-entry/package.json b/packages/multi-entry/package.json
index e925791ee..e02ce3939 100755
--- a/packages/multi-entry/package.json
+++ b/packages/multi-entry/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/pluginutils/package.json b/packages/pluginutils/package.json
index fcac22dd2..571137946 100644
--- a/packages/pluginutils/package.json
+++ b/packages/pluginutils/package.json
@@ -24,7 +24,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src --ext .js,.ts",
+    "lint:js": "eslint --fix --cache src test types --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
@@ -47,6 +47,7 @@
     "rollup": "^1.20.0"
   },
   "dependencies": {
+    "@types/estree": "0.0.39",
     "estree-walker": "^1.0.1",
     "micromatch": "^4.0.2"
   },
@@ -54,7 +55,6 @@
     "@rollup/plugin-commonjs": "^11.0.2",
     "@rollup/plugin-node-resolve": "^7.1.1",
     "@rollup/plugin-typescript": "^3.0.0",
-    "@types/estree": "0.0.39",
     "@types/jest": "^24.9.0",
     "@types/micromatch": "^3.1.1",
     "@types/node": "^12.12.25",
diff --git a/packages/pluginutils/rollup.config.js b/packages/pluginutils/rollup.config.js
index 8b69e3db0..a2ddd2e94 100755
--- a/packages/pluginutils/rollup.config.js
+++ b/packages/pluginutils/rollup.config.js
@@ -9,7 +9,7 @@ export default {
   plugins: [
     resolve(),
     commonjs({ include: '../../node_modules/.pnpm/registry.npmjs.org/**' }),
-    typescript({ include: '**/*.{ts,js}' })
+    typescript({ include: '**/*.{ts,js}', module: 'esnext' })
   ],
   external: Object.keys(pkg.dependencies).concat('path', 'util'),
   output: [
diff --git a/packages/pluginutils/src/attachScopes.ts b/packages/pluginutils/src/attachScopes.ts
index 83856ca23..d48b90a39 100755
--- a/packages/pluginutils/src/attachScopes.ts
+++ b/packages/pluginutils/src/attachScopes.ts
@@ -100,7 +100,7 @@ const attachScopes: AttachScopes = function attachScopes(ast, propertyName = 'sc
       }
 
       // create new block scope
-      if (node.type === 'BlockStatement' && !/Function/.test(parent!.type)) {
+      if (node.type === 'BlockStatement' && !/Function/.test(parent.type)) {
         newScope = new Scope({
           parent: scope,
           block: true
diff --git a/packages/pluginutils/tsconfig.json b/packages/pluginutils/tsconfig.json
index dc3cca649..56aa7e6a4 100644
--- a/packages/pluginutils/tsconfig.json
+++ b/packages/pluginutils/tsconfig.json
@@ -1,11 +1,12 @@
 {
   "extends": "../../tsconfig.base.json",
   "compilerOptions": {
-    "lib": ["es6"],
-    "esModuleInterop": true
+    "esModuleInterop": true,
+    "module": "commonjs"
   },
   "include": [
     "src/**/*",
+    "test/**/*",
     "types/**/*"
   ]
 }
diff --git a/packages/pluginutils/types/index.d.ts b/packages/pluginutils/types/index.d.ts
index d03411b67..33d40e509 100755
--- a/packages/pluginutils/types/index.d.ts
+++ b/packages/pluginutils/types/index.d.ts
@@ -1,14 +1,11 @@
+// eslint-disable-next-line import/no-unresolved
 import { BaseNode } from 'estree';
 
 export interface AttachedScope {
   parent?: AttachedScope;
   isBlockScope: boolean;
   declarations: { [key: string]: boolean };
-  addDeclaration(
-    node: BaseNode,
-    isBlockDeclaration: boolean,
-    isVar: boolean
-  ): void;
+  addDeclaration(node: BaseNode, isBlockDeclaration: boolean, isVar: boolean): void;
   contains(name: string): boolean;
 }
 
@@ -35,10 +32,7 @@ export function addExtension(filename: string, ext?: string): string;
  * Each `Scope` object has a `scope.contains(name)` method that returns `true`
  * if a given name is defined in the current scope or a parent scope.
  */
-export function attachScopes(
-  ast: BaseNode,
-  propertyName?: string
-): AttachedScope;
+export function attachScopes(ast: BaseNode, propertyName?: string): AttachedScope;
 
 /**
  * Constructs a filter function which can be used to determine whether or not
diff --git a/packages/strip/package.json b/packages/strip/package.json
index b1e753fa0..afcef3ddd 100644
--- a/packages/strip/package.json
+++ b/packages/strip/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test/test.js",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "pretest": "pnpm run build",
     "test": "ava"
diff --git a/packages/strip/test/fixtures/assert/input.js b/packages/strip/test/fixtures/assert/input.js
index f3a59aa33..fddefeed9 100755
--- a/packages/strip/test/fixtures/assert/input.js
+++ b/packages/strip/test/fixtures/assert/input.js
@@ -1,3 +1,4 @@
+/* eslint-disable */
 function foo(message) {
   assert.equal(arguments.length, 1);
   assert.equal(typeof arguments[0], 'string');
diff --git a/packages/strip/test/fixtures/super-method/input.js b/packages/strip/test/fixtures/super-method/input.js
index 254c6f39b..2e4b21172 100755
--- a/packages/strip/test/fixtures/super-method/input.js
+++ b/packages/strip/test/fixtures/super-method/input.js
@@ -1,3 +1,4 @@
+/* eslint-disable */
 class Foo {
   bar() {
     a();
diff --git a/packages/strip/test/snapshots/test.js.md b/packages/strip/test/snapshots/test.js.md
index cc530b8c0..76bed0fd5 100644
--- a/packages/strip/test/snapshots/test.js.md
+++ b/packages/strip/test/snapshots/test.js.md
@@ -40,7 +40,8 @@ Generated by [AVA](https://ava.li).
 
 > Snapshot 1
 
-    `function foo(message) {␊
+    `/* eslint-disable */␊
+    function foo(message) {␊
       bar(message);␊
     }␊
     `
@@ -113,7 +114,8 @@ Generated by [AVA](https://ava.li).
 
 > Snapshot 1
 
-    `class Foo {␊
+    `/* eslint-disable */␊
+    class Foo {␊
       bar() {␊
         a();␊
         b();␊
diff --git a/packages/strip/test/snapshots/test.js.snap b/packages/strip/test/snapshots/test.js.snap
index a6c7c5620..5c1e641a4 100644
Binary files a/packages/strip/test/snapshots/test.js.snap and b/packages/strip/test/snapshots/test.js.snap differ
diff --git a/packages/sucrase/package.json b/packages/sucrase/package.json
index 6c88183d2..5e6198f34 100644
--- a/packages/sucrase/package.json
+++ b/packages/sucrase/package.json
@@ -22,7 +22,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/typescript/package.json b/packages/typescript/package.json
index 153184679..d8292c262 100644
--- a/packages/typescript/package.json
+++ b/packages/typescript/package.json
@@ -20,9 +20,10 @@
     "ci:lint": "pnpm run build && pnpm run lint",
     "ci:lint:commits": "commitlint --from=${CIRCLE_BRANCH} --to=${CIRCLE_SHA1}",
     "ci:test": "pnpm run test -- --verbose --serial",
-    "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
+    "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:json && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
     "lint:js": "eslint --fix --cache src test --ext .js,.ts",
+    "lint:json": "prettier --write **/tsconfig.json",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/typescript/test/fixtures/project-references/animals/tsconfig.json b/packages/typescript/test/fixtures/project-references/animals/tsconfig.json
index f6b2cc49e..2642d5c3d 100644
--- a/packages/typescript/test/fixtures/project-references/animals/tsconfig.json
+++ b/packages/typescript/test/fixtures/project-references/animals/tsconfig.json
@@ -1,10 +1,8 @@
-{
-  "extends": "../tsconfig-base.json",
-  "compilerOptions": {
-    "outDir": "../lib/animals",
-    "rootDir": ".",
-  },
-  "references": [
-    { "path": "../core" }
-  ]
-}
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "outDir": "../lib/animals",
+    "rootDir": "."
+  },
+  "references": [{ "path": "../core" }]
+}
diff --git a/packages/typescript/test/fixtures/project-references/core/tsconfig.json b/packages/typescript/test/fixtures/project-references/core/tsconfig.json
index 9b381b9a5..27a28497e 100644
--- a/packages/typescript/test/fixtures/project-references/core/tsconfig.json
+++ b/packages/typescript/test/fixtures/project-references/core/tsconfig.json
@@ -1,7 +1,7 @@
-{
-  "extends": "../tsconfig-base.json",
-  "compilerOptions": {
-    "outDir": "../lib/core",
-    "rootDir": "."
-  }
-}
\ No newline at end of file
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "outDir": "../lib/core",
+    "rootDir": "."
+  }
+}
diff --git a/packages/typescript/test/fixtures/project-references/tsconfig.json b/packages/typescript/test/fixtures/project-references/tsconfig.json
index a140d4ef8..40992837c 100644
--- a/packages/typescript/test/fixtures/project-references/tsconfig.json
+++ b/packages/typescript/test/fixtures/project-references/tsconfig.json
@@ -1,14 +1,14 @@
-{
-  "files": [],
-  "references": [
-    {
-      "path": "./core"
-    },
-    {
-      "path": "./animals"
-    },
-    {
-      "path": "./zoo"
-    }
-  ]
-}
\ No newline at end of file
+{
+  "files": [],
+  "references": [
+    {
+      "path": "./core"
+    },
+    {
+      "path": "./animals"
+    },
+    {
+      "path": "./zoo"
+    }
+  ]
+}
diff --git a/packages/typescript/test/fixtures/project-references/zoo/tsconfig.json b/packages/typescript/test/fixtures/project-references/zoo/tsconfig.json
index 318c0dc06..854eea033 100644
--- a/packages/typescript/test/fixtures/project-references/zoo/tsconfig.json
+++ b/packages/typescript/test/fixtures/project-references/zoo/tsconfig.json
@@ -1,12 +1,12 @@
-{
-  "extends": "../tsconfig-base.json",
-  "compilerOptions": {
-    "outDir": "../lib/zoo",
-    "rootDir": "."
-  },
-  "references": [
-    {
-      "path": "../animals"
-    }
-  ]
-}
\ No newline at end of file
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "outDir": "../lib/zoo",
+    "rootDir": "."
+  },
+  "references": [
+    {
+      "path": "../animals"
+    }
+  ]
+}
diff --git a/packages/typescript/test/fixtures/tsconfig-extends-module/tsconfig.json b/packages/typescript/test/fixtures/tsconfig-extends-module/tsconfig.json
index 5222ba6cb..60ecd8aae 100644
--- a/packages/typescript/test/fixtures/tsconfig-extends-module/tsconfig.json
+++ b/packages/typescript/test/fixtures/tsconfig-extends-module/tsconfig.json
@@ -1,6 +1,6 @@
-{
-  "extends": "shared-config",
-  "compilerOptions": {
-    "allowJs": true
-  }
-}
+{
+  "extends": "shared-config",
+  "compilerOptions": {
+    "allowJs": true
+  }
+}
diff --git a/packages/typescript/tsconfig.json b/packages/typescript/tsconfig.json
index d7cd9de94..0e6f93f42 100644
--- a/packages/typescript/tsconfig.json
+++ b/packages/typescript/tsconfig.json
@@ -1,13 +1,4 @@
 {
   "extends": "../../tsconfig.base.json",
-  "compilerOptions": {
-    "lib": ["es6"],
-    "module": "esnext",
-    "allowJs": true
-  },
-  "include": [
-    "src/**/*",
-    "types/**/*",
-    "typings-test.js"
-  ]
+  "include": ["src/**/*", "types/**/*"]
 }
diff --git a/packages/typescript/types/index.d.ts b/packages/typescript/types/index.d.ts
index 08e2e0f8d..76050f291 100644
--- a/packages/typescript/types/index.d.ts
+++ b/packages/typescript/types/index.d.ts
@@ -1,3 +1,4 @@
+import { FilterPattern } from '@rollup/pluginutils';
 import { Plugin } from 'rollup';
 import { CompilerOptionsValue, TsConfigSourceFile } from 'typescript';
 
@@ -17,12 +18,12 @@ export interface RollupTypescriptOptions {
    * Determine which files are transpiled by Typescript (all `.ts` and
    * `.tsx` files by default).
    */
-  include?: string | RegExp | Array<string | RegExp> | null;
+  include?: FilterPattern;
   /**
    * Determine which files are transpiled by Typescript (all `.ts` and
    * `.tsx` files by default).
    */
-  exclude?: string | RegExp | Array<string | RegExp> | null;
+  exclude?: FilterPattern;
   /**
    * When set to false, ignores any options specified in the config file.
    * If set to a string that corresponds to a file path, the specified file
diff --git a/packages/url/package.json b/packages/url/package.json
index f3e0b2636..c7e8f93bb 100644
--- a/packages/url/package.json
+++ b/packages/url/package.json
@@ -22,7 +22,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/virtual/package.json b/packages/virtual/package.json
index 90938dce5..a1f844a8d 100755
--- a/packages/virtual/package.json
+++ b/packages/virtual/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/wasm/package.json b/packages/wasm/package.json
index 57d684da9..266668e48 100644
--- a/packages/wasm/package.json
+++ b/packages/wasm/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/packages/yaml/package.json b/packages/yaml/package.json
index 88965698e..58d0724cf 100755
--- a/packages/yaml/package.json
+++ b/packages/yaml/package.json
@@ -19,7 +19,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5b1e33737..94351a7da 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -284,13 +284,13 @@ importers:
       string-capitalize: ^1.0.1
   packages/pluginutils:
     dependencies:
+      '@types/estree': 0.0.39
       estree-walker: 1.0.1
       micromatch: 4.0.2
     devDependencies:
       '@rollup/plugin-commonjs': 11.0.2
       '@rollup/plugin-node-resolve': 7.1.1
       '@rollup/plugin-typescript': 3.0.0_typescript@3.7.5
-      '@types/estree': 0.0.39
       '@types/jest': 24.9.0
       '@types/micromatch': 3.1.1
       '@types/node': 12.12.25
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 90a2ea4f9..1107da3b1 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -2,7 +2,7 @@
   "compilerOptions": {
     "allowSyntheticDefaultImports": true,
     "lib": ["es6"],
-    "module": "commonjs",
+    "module": "esnext",
     "moduleResolution": "node",
     "noEmit": true,
     "noEmitOnError": false,
diff --git a/tsconfig.eslint.json b/tsconfig.eslint.json
index ed0d4251a..74b673d48 100644
--- a/tsconfig.eslint.json
+++ b/tsconfig.eslint.json
@@ -1,8 +1,4 @@
 {
   "extends": "./tsconfig.base.json",
-  "include": [
-    "packages",
-    "scripts",
-    "util"
-  ]
+  "include": ["packages", "scripts", "util"]
 }