blob: a5a7a1bee85469fa01394e4f537a42d6000b97b6 [file] [log] [blame]
Leo Repp58b9f112021-11-22 11:57:47 +01001'use strict';
2
3var GetIntrinsic = require('get-intrinsic');
4
5var $TypeError = GetIntrinsic('%TypeError%');
6
7var callBound = require('call-bind/callBound');
8var regexTester = require('../helpers/regexTester');
9var every = require('../helpers/every');
10
11var $charAt = callBound('String.prototype.charAt');
12var $strSlice = callBound('String.prototype.slice');
13var $indexOf = callBound('String.prototype.indexOf');
14var $parseInt = parseInt;
15
16var isDigit = regexTester(/^[0-9]$/);
17
18var inspect = require('object-inspect');
19
20var Get = require('./Get');
21var IsArray = require('./IsArray');
22var IsInteger = require('./IsInteger');
23var ToObject = require('./ToObject');
24var ToString = require('./ToString');
25var Type = require('./Type');
26
27var canDistinguishSparseFromUndefined = 0 in [undefined]; // IE 6 - 8 have a bug where this returns false
28
29var isStringOrHole = function (capture, index, arr) {
30 return Type(capture) === 'String' || (canDistinguishSparseFromUndefined ? !(index in arr) : Type(capture) === 'Undefined');
31};
32
33// http://262.ecma-international.org/9.0/#sec-getsubstitution
34
35// eslint-disable-next-line max-statements, max-params, max-lines-per-function
36module.exports = function GetSubstitution(matched, str, position, captures, namedCaptures, replacement) {
37 if (Type(matched) !== 'String') {
38 throw new $TypeError('Assertion failed: `matched` must be a String');
39 }
40 var matchLength = matched.length;
41
42 if (Type(str) !== 'String') {
43 throw new $TypeError('Assertion failed: `str` must be a String');
44 }
45 var stringLength = str.length;
46
47 if (!IsInteger(position) || position < 0 || position > stringLength) {
48 throw new $TypeError('Assertion failed: `position` must be a nonnegative integer, and less than or equal to the length of `string`, got ' + inspect(position));
49 }
50
51 if (!IsArray(captures) || !every(captures, isStringOrHole)) {
52 throw new $TypeError('Assertion failed: `captures` must be a List of Strings, got ' + inspect(captures));
53 }
54
55 if (Type(replacement) !== 'String') {
56 throw new $TypeError('Assertion failed: `replacement` must be a String');
57 }
58
59 var tailPos = position + matchLength;
60 var m = captures.length;
61 if (Type(namedCaptures) !== 'Undefined') {
62 namedCaptures = ToObject(namedCaptures); // eslint-disable-line no-param-reassign
63 }
64
65 var result = '';
66 for (var i = 0; i < replacement.length; i += 1) {
67 // if this is a $, and it's not the end of the replacement
68 var current = $charAt(replacement, i);
69 var isLast = (i + 1) >= replacement.length;
70 var nextIsLast = (i + 2) >= replacement.length;
71 if (current === '$' && !isLast) {
72 var next = $charAt(replacement, i + 1);
73 if (next === '$') {
74 result += '$';
75 i += 1;
76 } else if (next === '&') {
77 result += matched;
78 i += 1;
79 } else if (next === '`') {
80 result += position === 0 ? '' : $strSlice(str, 0, position - 1);
81 i += 1;
82 } else if (next === "'") {
83 result += tailPos >= stringLength ? '' : $strSlice(str, tailPos);
84 i += 1;
85 } else {
86 var nextNext = nextIsLast ? null : $charAt(replacement, i + 2);
87 if (isDigit(next) && next !== '0' && (nextIsLast || !isDigit(nextNext))) {
88 // $1 through $9, and not followed by a digit
89 var n = $parseInt(next, 10);
90 // if (n > m, impl-defined)
91 result += n <= m && Type(captures[n - 1]) === 'Undefined' ? '' : captures[n - 1];
92 i += 1;
93 } else if (isDigit(next) && (nextIsLast || isDigit(nextNext))) {
94 // $00 through $99
95 var nn = next + nextNext;
96 var nnI = $parseInt(nn, 10) - 1;
97 // if nn === '00' or nn > m, impl-defined
98 result += nn <= m && Type(captures[nnI]) === 'Undefined' ? '' : captures[nnI];
99 i += 2;
100 } else if (next === '<') {
101 // eslint-disable-next-line max-depth
102 if (Type(namedCaptures) === 'Undefined') {
103 result += '$<';
104 i += 2;
105 } else {
106 var endIndex = $indexOf(replacement, '>', i);
107 // eslint-disable-next-line max-depth
108 if (endIndex > -1) {
109 var groupName = $strSlice(replacement, i + '$<'.length, endIndex);
110 var capture = Get(namedCaptures, groupName);
111 // eslint-disable-next-line max-depth
112 if (Type(capture) !== 'Undefined') {
113 result += ToString(capture);
114 }
115 i += ('<' + groupName + '>').length;
116 }
117 }
118 } else {
119 result += '$';
120 }
121 }
122 } else {
123 // the final $, or else not a $
124 result += $charAt(replacement, i);
125 }
126 }
127 return result;
128};