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repl: handle stage-3 language features properly
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This adds stage-3 language features to acorn so that the REPL is
able to parse these features properly. Otherwise these would cause
SyntaxErrors.

PR-URL: #27400
Fixes: #27391
Fixes: #25835
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Michaël Zasso <[email protected]>
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BridgeAR authored and targos committed Apr 30, 2019
1 parent 01d632d commit 05cea67
Showing 1 changed file with 46 additions and 26 deletions.
72 changes: 46 additions & 26 deletions lib/internal/repl/utils.js
Original file line number Diff line number Diff line change
@@ -1,13 +1,28 @@
'use strict';

const acorn = require('internal/deps/acorn/acorn/dist/acorn');
const privateMethods =
require('internal/deps/acorn-plugins/acorn-private-methods/index');
const bigInt = require('internal/deps/acorn-plugins/acorn-bigint/index');
const classFields =
require('internal/deps/acorn-plugins/acorn-class-fields/index');
const numericSeparator =
require('internal/deps/acorn-plugins/acorn-numeric-separator/index');
const staticClassFeatures =
require('internal/deps/acorn-plugins/acorn-static-class-features/index');
const { tokTypes: tt, Parser: AcornParser } = acorn;

// If the error is that we've unexpectedly ended the input,
// then let the user try to recover by adding more input.
// Note: `e` (the original exception) is not used by the current implementation,
// but may be needed in the future.
function isRecoverableError(e, code) {
// For similar reasons as `defaultEval`, wrap expressions starting with a
// curly brace with parenthesis. Note: only the open parenthesis is added
// here as the point is to test for potentially valid but incomplete
// expressions.
if (/^\s*\{/.test(code) && isRecoverableError(e, `(${code}`)) return true;

let recoverable = false;

// Determine if the point of any error raised is at the end of the input.
Expand All @@ -26,34 +41,39 @@ function isRecoverableError(e, code) {
// change these messages in the future, this will lead to a test
// failure, indicating that this code needs to be updated.
//
const RecoverableParser = AcornParser.extend((Parser) => {
return class extends Parser {
nextToken() {
super.nextToken();
if (this.type === tt.eof) recoverable = true;
}
raise(pos, message) {
switch (message) {
case 'Unterminated template':
case 'Unterminated comment':
recoverable = true;
break;
const RecoverableParser = AcornParser
.extend(
privateMethods,
bigInt,
classFields,
numericSeparator,
staticClassFeatures,
(Parser) => {
return class extends Parser {
nextToken() {
super.nextToken();
if (this.type === tt.eof)
recoverable = true;
}
raise(pos, message) {
switch (message) {
case 'Unterminated template':
case 'Unterminated comment':
recoverable = true;
break;

case 'Unterminated string constant':
const token = this.input.slice(this.lastTokStart, this.pos);
// See https://www.ecma-international.org/ecma-262/#sec-line-terminators
recoverable = /\\(?:\r\n?|\n|\u2028|\u2029)$/.test(token);
}
super.raise(pos, message);
case 'Unterminated string constant':
const token = this.input.slice(this.lastTokStart, this.pos);
// See https://www.ecma-international.org/ecma-262/#sec-line-terminators
if (/\\(?:\r\n?|\n|\u2028|\u2029)$/.test(token)) {
recoverable = true;
}
}
super.raise(pos, message);
}
};
}
};
});

// For similar reasons as `defaultEval`, wrap expressions starting with a
// curly brace with parenthesis. Note: only the open parenthesis is added
// here as the point is to test for potentially valid but incomplete
// expressions.
if (/^\s*\{/.test(code) && isRecoverableError(e, `(${code}`)) return true;
);

// Try to parse the code with acorn. If the parse fails, ignore the acorn
// error and return the recoverable status.
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