Provide plugin/preset typings from plugin-utils

packages/babel-core/src/config/helpers/config-api.ts

@@ -24,7 +24,7 @@ type CallerFactory = (
   extractor: (callerMetadata: CallerMetadata | void) => unknown,
 ) => SimpleType;
 type TargetsFunction = () => Targets;
-type AssumptionFunction = (name: AssumptionName) => boolean;
+type AssumptionFunction = (name: AssumptionName) => boolean | void;
 
 export type ConfigAPI = {
   version: string;

packages/babel-helper-create-class-features-plugin/src/index.ts

@@ -185,7 +185,7 @@ export function createClassFeaturePlugin({
         const privateNamesMap = buildPrivateNamesMap(props);
         const privateNamesNodes = buildPrivateNamesNodes(
           privateNamesMap,
-          privateFieldsAsProperties ?? loose,
+          (privateFieldsAsProperties ?? loose) as boolean,
           state,
         );
 
@@ -224,9 +224,9 @@ export function createClassFeaturePlugin({
               props,
               privateNamesMap,
               state,
-              setPublicClassFields ?? loose,
-              privateFieldsAsProperties ?? loose,
-              constantSuper ?? loose,
+              (setPublicClassFields ?? loose) as boolean,
+              (privateFieldsAsProperties ?? loose) as boolean,
+              (constantSuper ?? loose) as boolean,
               innerBinding,
             ));
         }

packages/babel-helper-module-transforms/src/index.ts

@@ -185,7 +185,7 @@ export function wrapInterop(
 export function buildNamespaceInitStatements(
   metadata: ModuleMetadata,
   sourceMetadata: SourceModuleMetadata,
-  constantReexports: boolean = false,
+  constantReexports: boolean | void = false,
 ) {
   const statements = [];
 

packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/src/index.ts

@@ -7,8 +7,8 @@ import type * as t from "@babel/types";
 export default declare(api => {
   api.assertVersion(7);
 
-  const noDocumentAll = api.assumption("noDocumentAll");
-  const pureGetters = api.assumption("pureGetters");
+  const noDocumentAll = (api.assumption("noDocumentAll") ?? false) as boolean;
+  const pureGetters = (api.assumption("pureGetters") ?? false) as boolean;
 
   return {
     name: "bugfix-v8-spread-parameters-in-optional-chaining",

packages/babel-plugin-proposal-optional-chaining/src/index.ts

@@ -11,8 +11,8 @@ export default declare((api, options: Options) => {
   api.assertVersion(7);
 
   const { loose = false } = options;
-  const noDocumentAll = api.assumption("noDocumentAll") ?? loose;
-  const pureGetters = api.assumption("pureGetters") ?? loose;
+  const noDocumentAll = (api.assumption("noDocumentAll") ?? loose) as boolean;
+  const pureGetters = (api.assumption("pureGetters") ?? loose) as boolean;
 
   return {
     name: "proposal-optional-chaining",

packages/babel-plugin-transform-async-to-generator/src/index.ts

@@ -16,8 +16,9 @@ export default declare<State>((api, options: Options) => {
   api.assertVersion(7);
 
   const { method, module } = options;
-  const noNewArrows = api.assumption("noNewArrows");
-  const ignoreFunctionLength = api.assumption("ignoreFunctionLength");
+  const noNewArrows = (api.assumption("noNewArrows") ?? false) as boolean;
+  const ignoreFunctionLength = (api.assumption("ignoreFunctionLength") ??
+    false) as boolean;
 
   if (method && module) {
     return {

packages/babel-plugin-transform-classes/src/index.ts

@@ -22,13 +22,15 @@ export interface Options {
 export default declare((api, options: Options) => {
   api.assertVersion(7);
 
-  const { loose } = options;
-
-  const setClassMethods = api.assumption("setClassMethods") ?? options.loose;
-  const constantSuper = api.assumption("constantSuper") ?? options.loose;
-  const superIsCallableConstructor =
-    api.assumption("superIsCallableConstructor") ?? options.loose;
-  const noClassCalls = api.assumption("noClassCalls") ?? options.loose;
+  const { loose = false } = options;
+
+  const setClassMethods = (api.assumption("setClassMethods") ??
+    loose) as boolean;
+  const constantSuper = (api.assumption("constantSuper") ?? loose) as boolean;
+  const superIsCallableConstructor = (api.assumption(
+    "superIsCallableConstructor",
+  ) ?? loose) as boolean;
+  const noClassCalls = (api.assumption("noClassCalls") ?? loose) as boolean;
 
   // todo: investigate traversal requeueing
   const VISITED = Symbol();

packages/babel-plugin-transform-destructuring/src/index.ts

@@ -30,11 +30,15 @@ export default declare((api, options: Options) => {
 
   const { useBuiltIns = false } = options;
 
-  const iterableIsArray = api.assumption("iterableIsArray") ?? options.loose;
-  const arrayLikeIsIterable =
-    options.allowArrayLike ?? api.assumption("arrayLikeIsIterable");
-  const objectRestNoSymbols =
-    api.assumption("objectRestNoSymbols") ?? options.loose;
+  const iterableIsArray = (api.assumption("iterableIsArray") ??
+    options.loose ??
+    false) as boolean;
+  const arrayLikeIsIterable = (options.allowArrayLike ??
+    api.assumption("arrayLikeIsIterable") ??
+    false) as boolean;
+  const objectRestNoSymbols = (api.assumption("objectRestNoSymbols") ??
+    options.loose ??
+    false) as boolean;
 
   return {
     name: "transform-destructuring",

packages/babel-plugin-transform-modules-commonjs/src/index.ts

@@ -49,14 +49,14 @@ export default declare((api, options: Options) => {
     lazy = false,
     // Defaulting to 'true' for now. May change before 7.x major.
     allowCommonJSExports = true,
+    loose = false,
   } = options;
 
-  const constantReexports =
-    api.assumption("constantReexports") ?? options.loose;
-  const enumerableModuleMeta =
-    api.assumption("enumerableModuleMeta") ?? options.loose;
-  const noIncompleteNsImportDetection =
-    api.assumption("noIncompleteNsImportDetection") ?? false;
+  const constantReexports = api.assumption("constantReexports") ?? loose;
+  const enumerableModuleMeta = api.assumption("enumerableModuleMeta") ?? loose;
+  const noIncompleteNsImportDetection = (api.assumption(
+    "noIncompleteNsImportDetection",
+  ) ?? false) as boolean;
 
   if (
     typeof lazy !== "boolean" &&

packages/babel-traverse/src/path/conversion.ts

@@ -143,6 +143,10 @@ export function arrowFunctionToExpression(
     specCompliant = false,
     // TODO(Babel 8): Consider defaulting to `false` for spec compliancy
     noNewArrows = !specCompliant,
+  }: {
+    allowInsertArrow?: boolean | void;
+    specCompliant?: boolean | void;
+    noNewArrows?: boolean | void;
   } = {},
 ) {
   if (!this.isArrowFunctionExpression()) {
@@ -217,8 +221,8 @@ const getSuperCallsVisitor = mergeVisitors<{
 function hoistFunctionEnvironment(
   fnPath: NodePath<t.Function>,
   // TODO(Babel 8): Consider defaulting to `false` for spec compliancy
-  noNewArrows = true,
-  allowInsertArrow = true,
+  noNewArrows: boolean | void = true,
+  allowInsertArrow: boolean | void = true,
 ): { thisBinding: string; fnPath: NodePath<t.Function> } {
   let arrowParent;
   let thisEnvFn = fnPath.findParent(p => {

packages/babel-traverse/src/scope/index.ts

@@ -640,7 +640,11 @@ export default class Scope {
   }
 
   // TODO: (Babel 8) Split i in two parameters, and use an object of flags
-  toArray(node: t.Node, i?: number | boolean, arrayLikeIsIterable?: boolean) {
+  toArray(
+    node: t.Node,
+    i?: number | boolean,
+    arrayLikeIsIterable?: boolean | void,
+  ) {
     if (isIdentifier(node)) {
       const binding = this.getBinding(node.name);
       if (binding?.constant && binding.path.isGenericType("Array")) {