fix handling of fractional number part and some special cases in `Num…

…ber.fromString`
zloirock · Oct 28, 2023 · f7b095e · f7b095e
1 parent 79ea4a7
commit f7b095e
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Showing 4 changed files with 47 additions and 7 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -3,6 +3,7 @@
 - Simplified `structuredClone` polyfill, avoided second tree pass in cases of transferring
 - Added support of `SuppressedError` to `structuredClone` polyfill
 - Removed unspecified unnecessary `ArrayBuffer` and `DataView` dependencies of `structuredClone` lack of which could cause errors in some entries in IE10-
+- Fixed handling of fractional number part and some special cases in [`Number.fromString`](https://github.com/tc39/proposal-number-fromstring)
 - Compat data improvements:
   - Updated Opera Android 78 compat data mapping
 

diff --git a/packages/core-js/modules/esnext.number.from-string.js b/packages/core-js/modules/esnext.number.from-string.js
@@ -9,30 +9,35 @@ var INVALID_RADIX = 'Invalid radix';
 var $RangeError = RangeError;
 var $SyntaxError = SyntaxError;
 var $TypeError = TypeError;
-var valid = /^[\da-z]+$/;
+var pow = Math.pow;
+var valid = /^[\d.a-z]+$/;
 var charAt = uncurryThis(''.charAt);
 var exec = uncurryThis(valid.exec);
 var numberToString = uncurryThis(1.0.toString);
 var stringSlice = uncurryThis(''.slice);
+var split = uncurryThis(''.split);
 
 // `Number.fromString` method
 // https://github.com/tc39/proposal-number-fromstring
 $({ target: 'Number', stat: true, forced: true }, {
   fromString: function fromString(string, radix) {
     var sign = 1;
-    var R, mathNum;
     if (typeof string != 'string') throw new $TypeError(INVALID_NUMBER_REPRESENTATION);
     if (!string.length) throw new $SyntaxError(INVALID_NUMBER_REPRESENTATION);
+    if (string === 'NaN') return NaN;
     if (charAt(string, 0) === '-') {
       sign = -1;
       string = stringSlice(string, 1);
-      if (!string.length) throw new $SyntaxError(INVALID_NUMBER_REPRESENTATION);
+      if (!string.length || string === '0') throw new $SyntaxError(INVALID_NUMBER_REPRESENTATION);
     }
-    R = radix === undefined ? 10 : toIntegerOrInfinity(radix);
+    if (string === 'Infinity') return sign * Infinity;
+    var R = radix === undefined ? 10 : toIntegerOrInfinity(radix);
     if (R < 2 || R > 36) throw new $RangeError(INVALID_RADIX);
-    if (!exec(valid, string) || numberToString(mathNum = parseInt(string, R), R) !== string) {
-      throw new $SyntaxError(INVALID_NUMBER_REPRESENTATION);
-    }
+    if (!exec(valid, string)) throw new $SyntaxError(INVALID_NUMBER_REPRESENTATION);
+    var parts = split(string, '.');
+    var mathNum = parseInt(parts[0], R);
+    if (parts.length > 1) mathNum += parseInt(parts[1], R) / pow(R, parts[1].length);
+    if (numberToString(mathNum, R) !== string) throw new $SyntaxError(INVALID_NUMBER_REPRESENTATION);
     return sign * mathNum;
   }
 });
diff --git a/tests/unit-global/esnext.number.from-string.js b/tests/unit-global/esnext.number.from-string.js
@@ -16,9 +16,26 @@ QUnit.test('Number.fromString', assert => {
     assert.same(fromString('10', radix), radix, `Radix ${ radix }`);
   }
   assert.throws(() => fromString('10', -4294967294), RangeError, 'Radix uses ToInteger #1');
+
+  assert.same(fromString('NaN'), NaN);
+  assert.same(fromString('NaN', 2), NaN);
+  assert.same(fromString('Infinity'), Infinity);
+  assert.same(fromString('Infinity', 2), Infinity);
+  assert.same(fromString('-Infinity'), -Infinity);
+  assert.same(fromString('-Infinity', 2), -Infinity);
+
   assert.same(fromString('10', 2.5), 2, 'Radix uses ToInteger #2');
   assert.same(fromString('42'), 42);
   assert.same(fromString('42', 10), 42);
+  assert.same(fromString('3.14159', 10), 3.14159);
+  assert.same(fromString('-100.11', 2), -4.75);
+  assert.same(fromString('202.1', 3), 20.333333333333332);
+
+  assert.same(fromString('0'), 0);
+  assert.same(fromString('0', 2), 0);
+  assert.throws(() => fromString('-0'), SyntaxError);
+  assert.throws(() => fromString('-0', 2), SyntaxError);
+
   assert.throws(() => fromString('0xc0ffee'), SyntaxError);
   assert.throws(() => fromString('0o755'), SyntaxError);
   assert.throws(() => fromString('0b00101010'), SyntaxError);

diff --git a/tests/unit-pure/esnext.number.from-string.js b/tests/unit-pure/esnext.number.from-string.js
@@ -15,9 +15,26 @@ QUnit.test('Number.fromString', assert => {
     assert.same(fromString('10', radix), radix, `Radix ${ radix }`);
   }
   assert.throws(() => fromString('10', -4294967294), RangeError, 'Radix uses ToInteger #1');
+
+  assert.same(fromString('NaN'), NaN);
+  assert.same(fromString('NaN', 2), NaN);
+  assert.same(fromString('Infinity'), Infinity);
+  assert.same(fromString('Infinity', 2), Infinity);
+  assert.same(fromString('-Infinity'), -Infinity);
+  assert.same(fromString('-Infinity', 2), -Infinity);
+
   assert.same(fromString('10', 2.5), 2, 'Radix uses ToInteger #2');
   assert.same(fromString('42'), 42);
   assert.same(fromString('42', 10), 42);
+  assert.same(fromString('3.14159', 10), 3.14159);
+  assert.same(fromString('-100.11', 2), -4.75);
+  assert.same(fromString('202.1', 3), 20.333333333333332);
+
+  assert.same(fromString('0'), 0);
+  assert.same(fromString('0', 2), 0);
+  assert.throws(() => fromString('-0'), SyntaxError);
+  assert.throws(() => fromString('-0', 2), SyntaxError);
+
   assert.throws(() => fromString('0xc0ffee'), SyntaxError);
   assert.throws(() => fromString('0o755'), SyntaxError);
   assert.throws(() => fromString('0b00101010'), SyntaxError);