typescript.js

"use strict";

const t = require("../../");
const stringifyValidator = require("../utils/stringifyValidator");
const toFunctionName = require("../utils/toFunctionName");

// For backward compat, we cannot use TS 3.7 syntax in published packages
const ts3_7 = process.argv.includes("--ts3.7");

// TypeScript 3.7: https://github.com/microsoft/TypeScript/pull/32695 will allow assert declarations
const asserts = ts3_7 ? assertion => `asserts ${assertion}` : () => `void`;

let code = `// NOTE: This file is autogenerated. Do not modify.
// See packages/babel-types/scripts/generators/typescript.js for script used.

interface BaseComment {
  value: string;
  start: number;
  end: number;
  loc: SourceLocation;
  type: "CommentBlock" | "CommentLine";
}

export interface CommentBlock extends BaseComment {
  type: "CommentBlock";
}

export interface CommentLine extends BaseComment {
  type: "CommentLine";
}

export type Comment = CommentBlock | CommentLine;

export interface SourceLocation {
  start: {
    line: number;
    column: number;
  };

  end: {
    line: number;
    column: number;
  };
}

interface BaseNode {
  leadingComments: ReadonlyArray<Comment> | null;
  innerComments: ReadonlyArray<Comment> | null;
  trailingComments: ReadonlyArray<Comment> | null;
  start: number | null;
  end: number | null;
  loc: SourceLocation | null;
  type: Node["type"];
  extra?: Record<string, unknown>;
}

export type Node = ${t.TYPES.sort().join(" | ")};\n\n`;

//

const lines = [];

for (const type in t.NODE_FIELDS) {
  const fields = t.NODE_FIELDS[type];
  const fieldNames = sortFieldNames(Object.keys(t.NODE_FIELDS[type]), type);
  const builderNames = t.BUILDER_KEYS[type];

  const struct = ['type: "' + type + '";'];
  const args = [];

  fieldNames.forEach(fieldName => {
    const field = fields[fieldName];
    // Future / annoying TODO:
    // MemberExpression.property, ObjectProperty.key and ObjectMethod.key need special cases; either:
    // - convert the declaration to chain() like ClassProperty.key and ClassMethod.key,
    // - declare an alias type for valid keys, detect the case and reuse it here,
    // - declare a disjoint union with, for example, ObjectPropertyBase,
    //   ObjectPropertyLiteralKey and ObjectPropertyComputedKey, and declare ObjectProperty
    //   as "ObjectPropertyBase & (ObjectPropertyLiteralKey | ObjectPropertyComputedKey)"
    let typeAnnotation = stringifyValidator(field.validate, "");

    if (isNullable(field) && !hasDefault(field)) {
      typeAnnotation += " | null";
    }

    if (builderNames.includes(fieldName)) {
      if (areAllRemainingFieldsNullable(fieldName, builderNames, fields)) {
        args.push(
          `${t.toBindingIdentifierName(fieldName)}${
            isNullable(field) ? "?:" : ":"
          } ${typeAnnotation}`
        );
      } else {
        args.push(
          `${t.toBindingIdentifierName(fieldName)}: ${typeAnnotation}${
            isNullable(field) ? " | undefined" : ""
          }`
        );
      }
    }

    const alphaNumeric = /^\w+$/;

    if (t.isValidIdentifier(fieldName) || alphaNumeric.test(fieldName)) {
      struct.push(`${fieldName}: ${typeAnnotation};`);
    } else {
      struct.push(`"${fieldName}": ${typeAnnotation};`);
    }
  });

  code += `export interface ${type} extends BaseNode {
  ${struct.join("\n  ").trim()}
}\n\n`;

  // super and import are reserved words in JavaScript
  if (type !== "Super" && type !== "Import") {
    lines.push(
      `export function ${toFunctionName(type)}(${args.join(", ")}): ${type};`
    );
  } else {
    const functionName = toFunctionName(type);
    lines.push(
      `declare function _${functionName}(${args.join(", ")}): ${type};`,
      `export { _${functionName} as ${functionName}}`
    );
  }
}

for (const typeName of t.TYPES) {
  const isDeprecated = !!t.DEPRECATED_KEYS[typeName];
  const realName = isDeprecated ? t.DEPRECATED_KEYS[typeName] : typeName;

  const result =
    t.NODE_FIELDS[realName] || t.FLIPPED_ALIAS_KEYS[realName]
      ? `node is ${realName}`
      : "boolean";

  if (isDeprecated) {
    lines.push(`/** @deprecated Use \`is${realName}\` */`);
  }
  lines.push(
    `export function is${typeName}(node: object | null | undefined, opts?: object | null): ${result};`
  );

  if (isDeprecated) {
    lines.push(`/** @deprecated Use \`assert${realName}\` */`);
  }
  lines.push(
    `export function assert${typeName}(node: object | null | undefined, opts?: object | null): ${asserts(
      result === "boolean" ? "node" : result
    )};`
  );
}

lines.push(
  // assert/
  `export function assertNode(obj: any): ${asserts("obj is Node")}`,

  // builders/
  // eslint-disable-next-line max-len
  `export function createTypeAnnotationBasedOnTypeof(type: 'string' | 'number' | 'undefined' | 'boolean' | 'function' | 'object' | 'symbol'): StringTypeAnnotation | VoidTypeAnnotation | NumberTypeAnnotation | BooleanTypeAnnotation | GenericTypeAnnotation`,
  `export function createUnionTypeAnnotation<T extends FlowType>(types: [T]): T`,
  `export function createFlowUnionType<T extends FlowType>(types: [T]): T`,
  // this probably misbehaves if there are 0 elements, and it's not a UnionTypeAnnotation if there's only 1
  // it is possible to require "2 or more" for this overload ([T, T, ...T[]]) but it requires typescript 3.0
  `export function createUnionTypeAnnotation(types: ReadonlyArray<FlowType>): UnionTypeAnnotation`,
  `export function createFlowUnionType(types: ReadonlyArray<FlowType>): UnionTypeAnnotation`,
  // this smells like "internal API"
  // eslint-disable-next-line max-len
  `export function buildChildren(node: { children: ReadonlyArray<JSXText | JSXExpressionContainer | JSXSpreadChild | JSXElement | JSXFragment | JSXEmptyExpression> }): JSXElement['children']`,

  // clone/
  `export function clone<T extends Node>(n: T): T;`,
  `export function cloneDeep<T extends Node>(n: T): T;`,
  `export function cloneDeepWithoutLoc<T extends Node>(n: T): T;`,
  `export function cloneNode<T extends Node>(n: T, deep?: boolean, withoutLoc?: boolean): T;`,
  `export function cloneWithoutLoc<T extends Node>(n: T): T;`,

  // comments/
  `export type CommentTypeShorthand = 'leading' | 'inner' | 'trailing'`,
  // eslint-disable-next-line max-len
  `export function addComment<T extends Node>(node: T, type: CommentTypeShorthand, content: string, line?: boolean): T`,
  // eslint-disable-next-line max-len
  `export function addComments<T extends Node>(node: T, type: CommentTypeShorthand, comments: ReadonlyArray<Comment>): T`,
  `export function inheritInnerComments(node: Node, parent: Node): void`,
  `export function inheritLeadingComments(node: Node, parent: Node): void`,
  `export function inheritsComments<T extends Node>(node: T, parent: Node): void`,
  `export function inheritTrailingComments(node: Node, parent: Node): void`,
  `export function removeComments<T extends Node>(node: T): T`,

  // converters/
  // eslint-disable-next-line max-len
  `export function ensureBlock(node: Extract<Node, { body: BlockStatement | Statement | Expression }>): BlockStatement`,
  // too complex?
  // eslint-disable-next-line max-len
  `export function ensureBlock<K extends keyof Extract<Node, { body: BlockStatement | Statement | Expression }> = 'body'>(node: Extract<Node, Record<K, BlockStatement | Statement | Expression>>, key: K): BlockStatement`,
  // gatherSequenceExpressions is not exported
  `export function toBindingIdentifierName(name: { toString(): string } | null | undefined): string`,
  `export function toBlock(node: Statement | Expression, parent?: Function | null): BlockStatement`,
  // it is possible for `node` to be an arbitrary object if `key` is always provided,
  // but that doesn't look like intended API
  // eslint-disable-next-line max-len
  `export function toComputedKey<T extends Extract<Node, { computed: boolean | null }>>(node: T, key?: Expression | Identifier): Expression`,
  `export function toExpression(node: Function): FunctionExpression`,
  `export function toExpression(node: Class): ClassExpression`,
  `export function toExpression(node: ExpressionStatement | Expression | Class | Function): Expression`,
  `export function toIdentifier(name: { toString(): string } | null | undefined): string`,
  `export function toKeyAlias(node: Method | Property, key?: Node): string`,
  // NOTE: this actually uses Scope from @babel/traverse, but we can't add a dependency on its types,
  // as they live in @types. Declare the structural subset that is required.
  // eslint-disable-next-line max-len
  `export function toSequenceExpression(nodes: ReadonlyArray<Node>, scope: { push(value: { id: LVal; kind: 'var'; init?: Expression}): void; buildUndefinedNode(): Node }): SequenceExpression | undefined`,
  `export function toStatement(node: AssignmentExpression, ignore?: boolean): ExpressionStatement`,
  `export function toStatement(node: Statement | AssignmentExpression, ignore?: boolean): Statement`,
  `export function toStatement(node: Class, ignore: true): ClassDeclaration | undefined`,
  `export function toStatement(node: Class, ignore?: boolean): ClassDeclaration`,
  `export function toStatement(node: Function, ignore: true): FunctionDeclaration | undefined`,
  `export function toStatement(node: Function, ignore?: boolean): FunctionDeclaration`,
  // eslint-disable-next-line max-len
  `export function toStatement(node: Statement | Class | Function | AssignmentExpression, ignore: true): Statement | undefined`,
  // eslint-disable-next-line max-len
  `export function toStatement(node: Statement | Class | Function | AssignmentExpression, ignore?: boolean): Statement`,
  // eslint-disable-next-line max-len
  `export function valueToNode(value: undefined): Identifier`, // (should this not be a UnaryExpression to avoid shadowing?)
  `export function valueToNode(value: boolean): BooleanLiteral`,
  `export function valueToNode(value: null): NullLiteral`,
  `export function valueToNode(value: string): StringLiteral`,
  // Infinities and NaN need to use a BinaryExpression; negative values must be wrapped in UnaryExpression
  `export function valueToNode(value: number): NumericLiteral | BinaryExpression | UnaryExpression`,
  `export function valueToNode(value: RegExp): RegExpLiteral`,
  // eslint-disable-next-line max-len
  `export function valueToNode(value: ReadonlyArray<undefined | boolean | null | string | number | RegExp | object>): ArrayExpression`,
  // this throws with objects that are not PlainObject according to lodash,
  // or if there are non-valueToNode-able values
  `export function valueToNode(value: object): ObjectExpression`,
  // eslint-disable-next-line max-len
  `export function valueToNode(value: undefined | boolean | null | string | number | RegExp | object): Expression`,

  // modifications/
  // eslint-disable-next-line max-len
  `export function removeTypeDuplicates(types: ReadonlyArray<FlowType | false | null | undefined>): FlowType[]`,
  // eslint-disable-next-line max-len
  `export function appendToMemberExpression<T extends Pick<MemberExpression, 'object' | 'property'>>(member: T, append: MemberExpression['property'], computed?: boolean): T`,
  // eslint-disable-next-line max-len
  `export function inherits<T extends Node | null | undefined>(child: T, parent: Node | null | undefined): T`,
  // eslint-disable-next-line max-len
  `export function prependToMemberExpression<T extends Pick<MemberExpression, 'object' | 'property'>>(member: T, prepend: MemberExpression['object']): T`,
  `export function removeProperties(
  n: Node,
  opts?: { preserveComments: boolean } | null
): void;`,
  `export function removePropertiesDeep<T extends Node>(
  n: T,
  opts?: { preserveComments: boolean } | null
): T;`,

  // retrievers/
  // eslint-disable-next-line max-len
  `export function getBindingIdentifiers(node: Node, duplicates: true, outerOnly?: boolean): Record<string, Array<Identifier>>`,
  // eslint-disable-next-line max-len
  `export function getBindingIdentifiers(node: Node, duplicates?: false, outerOnly?: boolean): Record<string, Identifier>`,
  // eslint-disable-next-line max-len
  `export function getBindingIdentifiers(node: Node, duplicates: boolean, outerOnly?: boolean): Record<string, Identifier | Array<Identifier>>`,
  // eslint-disable-next-line max-len
  `export function getOuterBindingIdentifiers(node: Node, duplicates: true): Record<string, Array<Identifier>>`,
  `export function getOuterBindingIdentifiers(node: Node, duplicates?: false): Record<string, Identifier>`,
  // eslint-disable-next-line max-len
  `export function getOuterBindingIdentifiers(node: Node, duplicates: boolean): Record<string, Identifier | Array<Identifier>>`,

  // traverse/
  `export type TraversalAncestors = ReadonlyArray<{
    node: Node,
    key: string,
    index?: number,
  }>;
  export type TraversalHandler<T> = (
    this: undefined, node: Node, parent: TraversalAncestors, type: T
  ) => void;
  export type TraversalHandlers<T> = {
    enter?: TraversalHandler<T>,
    exit?: TraversalHandler<T>,
  };`.replace(/(^|\n) {2}/g, "$1"),
  // eslint-disable-next-line
  `export function traverse<T>(n: Node, h: TraversalHandler<T> | TraversalHandlers<T>, state?: T): void;`,
  `export function traverseFast<T>(n: Node, h: TraversalHandler<T>, state?: T): void;`,

  // utils/
  // cleanJSXElementLiteralChild is not exported
  // inherit is not exported
  `export function shallowEqual<T extends object>(actual: object, expected: T): actual is T`,

  // validators/
  // eslint-disable-next-line max-len
  `export function buildMatchMemberExpression(match: string, allowPartial?: boolean): (node: Node | null | undefined) => node is MemberExpression`,
  // eslint-disable-next-line max-len
  `export function is<T extends Node['type']>(type: T, n: Node | null | undefined, required?: undefined): n is Extract<Node, { type: T }>`,
  // eslint-disable-next-line max-len
  `export function is<T extends Node['type'], P extends Extract<Node, { type: T }>>(type: T, n: Node | null | undefined, required: Partial<P>): n is P`,
  // eslint-disable-next-line max-len
  `export function is<P extends Node>(type: string, n: Node | null | undefined, required: Partial<P>): n is P`,
  `export function is(type: string, n: Node | null | undefined, required?: Partial<Node>): n is Node`,
  `export function isBinding(node: Node, parent: Node, grandparent?: Node): boolean`,
  // eslint-disable-next-line max-len
  `export function isBlockScoped(node: Node): node is FunctionDeclaration | ClassDeclaration | VariableDeclaration`,
  `export function isImmutable(node: Node): node is Immutable`,
  `export function isLet(node: Node): node is VariableDeclaration`,
  `export function isNode(node: object | null | undefined): node is Node`,
  `export function isNodesEquivalent<T extends Partial<Node>>(a: T, b: any): b is T`,
  `export function isNodesEquivalent(a: any, b: any): boolean`,
  `export function isPlaceholderType(placeholderType: Node['type'], targetType: Node['type']): boolean`,
  `export function isReferenced(node: Node, parent: Node, grandparent?: Node): boolean`,
  `export function isScope(node: Node, parent: Node): node is Scopable`,
  `export function isSpecifierDefault(specifier: ModuleSpecifier): boolean`,
  `export function isType<T extends Node['type']>(nodetype: string, targetType: T): nodetype is T`,
  `export function isType(nodetype: string | null | undefined, targetType: string): boolean`,
  `export function isValidES3Identifier(name: string): boolean`,
  `export function isValidIdentifier(name: string): boolean`,
  `export function isVar(node: Node): node is VariableDeclaration`,
  // the MemberExpression implication is incidental, but it follows from the implementation
  // eslint-disable-next-line max-len
  `export function matchesPattern(node: Node | null | undefined, match: string | ReadonlyArray<string>, allowPartial?: boolean): node is MemberExpression`,
  // eslint-disable-next-line max-len
  `export function validate<T extends Node, K extends keyof T>(n: Node | null | undefined, key: K, value: T[K]): ${asserts(
    "n is T"
  )}`,
  `export function validate(n: Node, key: string, value: any): void;`
);

for (const type in t.DEPRECATED_KEYS) {
  code += `/**
 * @deprecated Use \`${t.DEPRECATED_KEYS[type]}\`
 */
export type ${type} = ${t.DEPRECATED_KEYS[type]};\n
`;
}

for (const type in t.FLIPPED_ALIAS_KEYS) {
  const types = t.FLIPPED_ALIAS_KEYS[type];
  code += `export type ${type} = ${types
    .map(type => `${type}`)
    .join(" | ")};\n`;
}
code += "\n";

code += "export interface Aliases {\n";
for (const type in t.FLIPPED_ALIAS_KEYS) {
  code += `  ${type}: ${type};\n`;
}
code += "}\n\n";

code += lines.join("\n") + "\n";

//

process.stdout.write(code);

//

function areAllRemainingFieldsNullable(fieldName, fieldNames, fields) {
  const index = fieldNames.indexOf(fieldName);
  return fieldNames.slice(index).every(_ => isNullable(fields[_]));
}

function hasDefault(field) {
  return field.default != null;
}

function isNullable(field) {
  return field.optional || hasDefault(field);
}

function sortFieldNames(fields, type) {
  return fields.sort((fieldA, fieldB) => {
    const indexA = t.BUILDER_KEYS[type].indexOf(fieldA);
    const indexB = t.BUILDER_KEYS[type].indexOf(fieldB);
    if (indexA === indexB) return fieldA < fieldB ? -1 : 1;
    if (indexA === -1) return 1;
    if (indexB === -1) return -1;
    return indexA - indexB;
  });
}