123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254 |
- // copied from https://github.com/nodejs/node/blob/88799930794045795e8abac874730f9eba7e2300/lib/internal/repl/await.js
- 'use strict';
- const {
- ArrayFrom,
- ArrayPrototypeForEach,
- ArrayPrototypeIncludes,
- ArrayPrototypeJoin,
- ArrayPrototypePop,
- ArrayPrototypePush,
- FunctionPrototype,
- ObjectKeys,
- RegExpPrototypeSymbolReplace,
- StringPrototypeEndsWith,
- StringPrototypeIncludes,
- StringPrototypeIndexOf,
- StringPrototypeRepeat,
- StringPrototypeSplit,
- StringPrototypeStartsWith,
- SyntaxError,
- } = require('./node-primordials');
- const parser = require('acorn').Parser;
- const walk = require('acorn-walk');
- const { Recoverable } = require('repl');
- function isTopLevelDeclaration(state) {
- return state.ancestors[state.ancestors.length - 2] === state.body;
- }
- const noop = FunctionPrototype;
- const visitorsWithoutAncestors = {
- ClassDeclaration(node, state, c) {
- if (isTopLevelDeclaration(state)) {
- state.prepend(node, `${node.id.name}=`);
- ArrayPrototypePush(
- state.hoistedDeclarationStatements,
- `let ${node.id.name}; `
- );
- }
- walk.base.ClassDeclaration(node, state, c);
- },
- ForOfStatement(node, state, c) {
- if (node.await === true) {
- state.containsAwait = true;
- }
- walk.base.ForOfStatement(node, state, c);
- },
- FunctionDeclaration(node, state, c) {
- state.prepend(node, `${node.id.name}=`);
- ArrayPrototypePush(
- state.hoistedDeclarationStatements,
- `var ${node.id.name}; `
- );
- },
- FunctionExpression: noop,
- ArrowFunctionExpression: noop,
- MethodDefinition: noop,
- AwaitExpression(node, state, c) {
- state.containsAwait = true;
- walk.base.AwaitExpression(node, state, c);
- },
- ReturnStatement(node, state, c) {
- state.containsReturn = true;
- walk.base.ReturnStatement(node, state, c);
- },
- VariableDeclaration(node, state, c) {
- const variableKind = node.kind;
- const isIterableForDeclaration = ArrayPrototypeIncludes(
- ['ForOfStatement', 'ForInStatement'],
- state.ancestors[state.ancestors.length - 2].type
- );
- if (variableKind === 'var' || isTopLevelDeclaration(state)) {
- state.replace(
- node.start,
- node.start + variableKind.length + (isIterableForDeclaration ? 1 : 0),
- variableKind === 'var' && isIterableForDeclaration ?
- '' :
- 'void' + (node.declarations.length === 1 ? '' : ' (')
- );
- if (!isIterableForDeclaration) {
- ArrayPrototypeForEach(node.declarations, (decl) => {
- state.prepend(decl, '(');
- state.append(decl, decl.init ? ')' : '=undefined)');
- });
- if (node.declarations.length !== 1) {
- state.append(node.declarations[node.declarations.length - 1], ')');
- }
- }
- const variableIdentifiersToHoist = [
- ['var', []],
- ['let', []],
- ];
- function registerVariableDeclarationIdentifiers(node) {
- switch (node.type) {
- case 'Identifier':
- ArrayPrototypePush(
- variableIdentifiersToHoist[variableKind === 'var' ? 0 : 1][1],
- node.name
- );
- break;
- case 'ObjectPattern':
- ArrayPrototypeForEach(node.properties, (property) => {
- registerVariableDeclarationIdentifiers(property.value);
- });
- break;
- case 'ArrayPattern':
- ArrayPrototypeForEach(node.elements, (element) => {
- registerVariableDeclarationIdentifiers(element);
- });
- break;
- }
- }
- ArrayPrototypeForEach(node.declarations, (decl) => {
- registerVariableDeclarationIdentifiers(decl.id);
- });
- ArrayPrototypeForEach(
- variableIdentifiersToHoist,
- ({ 0: kind, 1: identifiers }) => {
- if (identifiers.length > 0) {
- ArrayPrototypePush(
- state.hoistedDeclarationStatements,
- `${kind} ${ArrayPrototypeJoin(identifiers, ', ')}; `
- );
- }
- }
- );
- }
- walk.base.VariableDeclaration(node, state, c);
- }
- };
- const visitors = {};
- for (const nodeType of ObjectKeys(walk.base)) {
- const callback = visitorsWithoutAncestors[nodeType] || walk.base[nodeType];
- visitors[nodeType] = (node, state, c) => {
- const isNew = node !== state.ancestors[state.ancestors.length - 1];
- if (isNew) {
- ArrayPrototypePush(state.ancestors, node);
- }
- callback(node, state, c);
- if (isNew) {
- ArrayPrototypePop(state.ancestors);
- }
- };
- }
- function processTopLevelAwait(src) {
- const wrapPrefix = '(async () => { ';
- const wrapped = `${wrapPrefix}${src} })()`;
- const wrappedArray = ArrayFrom(wrapped);
- let root;
- try {
- root = parser.parse(wrapped, { ecmaVersion: 'latest' });
- } catch (e) {
- if (StringPrototypeStartsWith(e.message, 'Unterminated '))
- throw new Recoverable(e);
- // If the parse error is before the first "await", then use the execution
- // error. Otherwise we must emit this parse error, making it look like a
- // proper syntax error.
- const awaitPos = StringPrototypeIndexOf(src, 'await');
- const errPos = e.pos - wrapPrefix.length;
- if (awaitPos > errPos)
- return null;
- // Convert keyword parse errors on await into their original errors when
- // possible.
- if (errPos === awaitPos + 6 &&
- StringPrototypeIncludes(e.message, 'Expecting Unicode escape sequence'))
- return null;
- if (errPos === awaitPos + 7 &&
- StringPrototypeIncludes(e.message, 'Unexpected token'))
- return null;
- const line = e.loc.line;
- const column = line === 1 ? e.loc.column - wrapPrefix.length : e.loc.column;
- let message = '\n' + StringPrototypeSplit(src, '\n')[line - 1] + '\n' +
- StringPrototypeRepeat(' ', column) +
- '^\n\n' + RegExpPrototypeSymbolReplace(/ \([^)]+\)/, e.message, '');
- // V8 unexpected token errors include the token string.
- if (StringPrototypeEndsWith(message, 'Unexpected token'))
- message += " '" +
- // Wrapper end may cause acorn to report error position after the source
- ((src.length - 1) >= (e.pos - wrapPrefix.length)
- ? src[e.pos - wrapPrefix.length]
- : src[src.length - 1]) +
- "'";
- // eslint-disable-next-line no-restricted-syntax
- throw new SyntaxError(message);
- }
- const body = root.body[0].expression.callee.body;
- const state = {
- body,
- ancestors: [],
- hoistedDeclarationStatements: [],
- replace(from, to, str) {
- for (let i = from; i < to; i++) {
- wrappedArray[i] = '';
- }
- if (from === to) str += wrappedArray[from];
- wrappedArray[from] = str;
- },
- prepend(node, str) {
- wrappedArray[node.start] = str + wrappedArray[node.start];
- },
- append(node, str) {
- wrappedArray[node.end - 1] += str;
- },
- containsAwait: false,
- containsReturn: false
- };
- walk.recursive(body, state, visitors);
- // Do not transform if
- // 1. False alarm: there isn't actually an await expression.
- // 2. There is a top-level return, which is not allowed.
- if (!state.containsAwait || state.containsReturn) {
- return null;
- }
- const last = body.body[body.body.length - 1];
- if (last.type === 'ExpressionStatement') {
- // For an expression statement of the form
- // ( expr ) ;
- // ^^^^^^^^^^ // last
- // ^^^^ // last.expression
- //
- // We do not want the left parenthesis before the `return` keyword;
- // therefore we prepend the `return (` to `last`.
- //
- // On the other hand, we do not want the right parenthesis after the
- // semicolon. Since there can only be more right parentheses between
- // last.expression.end and the semicolon, appending one more to
- // last.expression should be fine.
- state.prepend(last, 'return (');
- state.append(last.expression, ')');
- }
- return (
- ArrayPrototypeJoin(state.hoistedDeclarationStatements, '') +
- ArrayPrototypeJoin(wrappedArray, '')
- );
- }
- module.exports = {
- processTopLevelAwait
- };
|