Add decimalSeparator option

Author: jakeboone02

CHANGELOG.md

@@ -7,7 +7,14 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
-- N/A
+### Changed
+
+- Now requires ES2021+ (uses `String.prototype.replaceAll`).
+- In line with the rules of modern JavaScript syntax, repeated separators (e.g. `"1__0"` or `"1,,0"`) are considered invalid. The `allowTrailingInvalid` option will still permit evaluation of characters before any duplicate separators.
+
+### Added
+
+- Option `decimalSeparator`, accepting values `"."` (default) and `","`. When set to `","`, numbers will be evaluated with European-style decimal _comma_ (e.g. `1,0` is equivalent to `1`, not `10`).
 
 ## [v2.1.0] - 2025-06-09
 

bunfig.toml

@@ -2,3 +2,4 @@
 coverage = true
 coverageThreshold = 1
 coverageReporter = ["lcov", "text"]
+coveragePathIgnorePatterns = "src/numericQuantityTests.ts"

src/constants.ts

@@ -35,7 +35,8 @@ export const vulgarFractionToAsciiMap: Record<
 } as const;
 
 /**
- * Captures the individual elements of a numeric string.
+ * Captures the individual elements of a numeric string. Commas and underscores are allowed
+ * as separators, as long as they appear between digits and are not consecutive.
  *
  * Capture groups:
  *
@@ -59,20 +60,17 @@ export const vulgarFractionToAsciiMap: Record<
  * ```
  */
 export const numericRegex: RegExp =
-  /^(?=-?\s*\.\d|-?\s*\d)(-)?\s*((?:\d(?:[\d,_]*\d)?)*)(([eE][+-]?\d(?:[\d,_]*\d)?)?|\.\d(?:[\d,_]*\d)?([eE][+-]?\d(?:[\d,_]*\d)?)?|(\s+\d(?:[\d,_]*\d)?\s*)?\s*\/\s*\d(?:[\d,_]*\d)?)?$/;
+  /^(?=-?\s*\.\d|-?\s*\d)(-)?\s*((?:\d(?:[,_]\d|\d)*)*)(([eE][+-]?\d(?:[,_]\d|\d)*)?|\.\d(?:[,_]\d|\d)*([eE][+-]?\d(?:[,_]\d|\d)*)?|(\s+\d(?:[,_]\d|\d)*\s*)?\s*\/\s*\d(?:[,_]\d|\d)*)?$/;
 /**
  * Same as {@link numericRegex}, but allows (and ignores) trailing invalid characters.
  */
-export const numericRegexWithTrailingInvalid: RegExp = new RegExp(
-  numericRegex.source.replace(/\$$/, '(?:\\s*[^\\.\\d\\/].*)?')
-);
+export const numericRegexWithTrailingInvalid: RegExp =
+  /^(?=-?\s*\.\d|-?\s*\d)(-)?\s*((?:\d(?:[,_]\d|\d)*)*)(([eE][+-]?\d(?:[,_]\d|\d)*)?|\.\d(?:[,_]\d|\d)*([eE][+-]?\d(?:[,_]\d|\d)*)?|(\s+\d(?:[,_]\d|\d)*\s*)?\s*\/\s*\d(?:[,_]\d|\d)*)?(?:\s*[^.\d/].*)?/;
 
 /**
  * Captures any Unicode vulgar fractions.
  */
-export const vulgarFractionsRegex: RegExp = new RegExp(
-  `(${Object.keys(vulgarFractionToAsciiMap).join('|')})`
-);
+export const vulgarFractionsRegex: RegExp = /([¼½¾⅐⅑⅒⅓⅔⅕⅖⅗⅘⅙⅚⅛⅜⅝⅞⅟}])/g;
 // #endregion
 
 // #region Roman numerals
@@ -198,10 +196,8 @@ export const romanNumeralUnicodeToAsciiMap: Record<
 /**
  * Captures all Unicode Roman numeral code points.
  */
-export const romanNumeralUnicodeRegex: RegExp = new RegExp(
-  `(${Object.keys(romanNumeralUnicodeToAsciiMap).join('|')})`,
-  'gi'
-);
+export const romanNumeralUnicodeRegex: RegExp =
+  /([ⅠⅡⅢⅣⅤⅥⅦⅧⅨⅩⅪⅫⅬⅭⅮⅯⅰⅱⅲⅳⅴⅵⅶⅷⅸⅹⅺⅻⅼⅽⅾⅿ])/gi;
 
 /**
  * Captures a valid Roman numeral sequence.
@@ -236,4 +232,5 @@ export const defaultOptions: Required<NumericQuantityOptions> = {
   allowTrailingInvalid: false,
   romanNumerals: false,
   bigIntOnOverflow: false,
+  decimalSeparator: '.',
 } as const;

src/numericQuantity.ts

@@ -57,18 +57,55 @@ function numericQuantity(
     ...options,
   };
 
+  let normalizedString = quantityAsString;
+
+  if (opts.decimalSeparator === ',') {
+    const commaCount = (quantityAsString.match(/,/g) || []).length;
+    if (commaCount === 1) {
+      // Treat lone comma as decimal separator; remove all "." since they represent
+      // thousands/whatever separators
+      normalizedString = quantityAsString
+        .replaceAll('.', '_')
+        .replace(',', '.');
+    } else if (commaCount > 1) {
+      // The second comma and everything after is "trailing invalid"
+      if (!opts.allowTrailingInvalid) {
+        // Bail out if trailing invalid is not allowed
+        return NaN;
+      }
+
+      const firstCommaIndex = quantityAsString.indexOf(',');
+      const secondCommaIndex = quantityAsString.indexOf(
+        ',',
+        firstCommaIndex + 1
+      );
+      const beforeSecondComma = quantityAsString
+        .substring(0, secondCommaIndex)
+        .replaceAll('.', '_')
+        .replace(',', '.');
+      const afterSecondComma = quantityAsString.substring(secondCommaIndex + 1);
+      normalizedString = opts.allowTrailingInvalid
+        ? beforeSecondComma + '&' + afterSecondComma
+        : beforeSecondComma;
+    } else {
+      // No comma as decimal separator, so remove all "." since they represent
+      // thousands/whatever separators
+      normalizedString = quantityAsString.replaceAll('.', '_');
+    }
+  }
+
   const regexResult = (
     opts.allowTrailingInvalid ? numericRegexWithTrailingInvalid : numericRegex
-  ).exec(quantityAsString);
+  ).exec(normalizedString);
 
   // If the Arabic numeral regex fails, try Roman numerals
   if (!regexResult) {
     return opts.romanNumerals ? parseRomanNumerals(quantityAsString) : NaN;
   }
 
   const [, dash, ng1temp, ng2temp] = regexResult;
-  const numberGroup1 = ng1temp.replace(/[,_]/g, '');
-  const numberGroup2 = ng2temp?.replace(/[,_]/g, '');
+  const numberGroup1 = ng1temp.replaceAll(',', '').replaceAll('_', '');
+  const numberGroup2 = ng2temp?.replaceAll(',', '').replaceAll('_', '');
 
   // Numerify capture group 1
   if (!numberGroup1 && numberGroup2 && numberGroup2.startsWith('.')) {

src/numericQuantityTests.ts

@@ -5,9 +5,6 @@ const allowTrailingInvalid = true;
 const romanNumerals = true;
 
 const noop = () => {};
-// This is only executed to meet test coverage requirements until
-// https://github.com/oven-sh/bun/issues/4021 is implemented.
-noop();
 
 export const numericQuantityTests: Record<
   string,
@@ -81,7 +78,46 @@ export const numericQuantityTests: Record<
     ['1 2/3,4', 1.059],
     ['1 2/3_4', 1.059],
   ],
-  'Invalid/ignored separators': [
+  // TODO: Add support for automatic decimal separator detection
+  // 'Auto-detected decimal separator': [
+  //   ['1.0,00', 10, { decimalSeparator: 'auto' }],
+  //   ['1,00.0', 100, { decimalSeparator: 'auto' }],
+  //   ['10.0,00.1', NaN, { decimalSeparator: 'auto' }],
+  //   ['10,00.00,1', 1000.001, { decimalSeparator: 'auto' }],
+  //   ['100,100', 100.1, { decimalSeparator: 'auto' }],
+  //   ['100,1000', 100.1, { decimalSeparator: 'auto' }],
+  //   ['1000,100', 1000.1, { decimalSeparator: 'auto' }],
+  //   ['1000,1', 1000.1, { decimalSeparator: 'auto' }],
+  // ],
+  'Comma as decimal separator': [
+    ['1.0,00', 10, { decimalSeparator: ',' }],
+    ['1,00.0', 1, { decimalSeparator: ',' }],
+    ['1.00.0', 1000, { decimalSeparator: ',' }],
+    ['1,000,001', NaN, { decimalSeparator: ',' }],
+    ['1,000,001', 1, { decimalSeparator: ',', allowTrailingInvalid }],
+    ['1,00.1', 1.001, { decimalSeparator: ',', allowTrailingInvalid }],
+    ['10.0,00.0', 100, { decimalSeparator: ',' }],
+    ['10,00.00,0', NaN, { decimalSeparator: ',' }],
+    ['10,00.00,0', 10, { decimalSeparator: ',', allowTrailingInvalid }],
+    ['100,100', 100.1, { decimalSeparator: ',' }],
+    ['100,1000', 100.1, { decimalSeparator: ',' }],
+    ['1000,100', 1000.1, { decimalSeparator: ',' }],
+    ['1000,1', 1000.1, { decimalSeparator: ',' }],
+    ['1_.0,00', NaN, { decimalSeparator: ',' }],
+    ['1_,00.0', NaN, { decimalSeparator: ',' }],
+    ['1_.00.0', NaN, { decimalSeparator: ',' }],
+    ['1_,000,001', NaN, { decimalSeparator: ',' }],
+    ['1_,000,001', 1, { decimalSeparator: ',', allowTrailingInvalid }],
+    ['1_,00.1', 1, { decimalSeparator: ',', allowTrailingInvalid }],
+    ['1_0.0,00.0', 100, { decimalSeparator: ',' }],
+    ['1_0,00.00,0', NaN, { decimalSeparator: ',' }],
+    ['1_0,00.00,0', 10, { decimalSeparator: ',', allowTrailingInvalid }],
+    ['1_00,100', 100.1, { decimalSeparator: ',' }],
+    ['1_00,1000', 100.1, { decimalSeparator: ',' }],
+    ['1_000,100', 1000.1, { decimalSeparator: ',' }],
+    ['1_000,1', 1000.1, { decimalSeparator: ',' }],
+  ],
+  'Invalid/repeated/ignored separators': [
     ['_11 11/22', NaN],
     [',11 11/22', NaN],
     ['11 _11/22', NaN],
@@ -94,6 +130,10 @@ export const numericQuantityTests: Record<
     ['11 11,/22', NaN],
     ['11 11/22_', NaN],
     ['11 11/22,', NaN],
+    ['11__22', NaN],
+    ['11,,22', NaN],
+    ['11,_22', NaN],
+    ['11,_22', NaN],
     ['11 _11/22', 11, { allowTrailingInvalid }],
     ['11 ,11/22', 11, { allowTrailingInvalid }],
     ['11 11/_22', 11, { allowTrailingInvalid }],
@@ -104,6 +144,10 @@ export const numericQuantityTests: Record<
     ['11 11,/22', 11, { allowTrailingInvalid }],
     ['11 11/22_', 11.5, { allowTrailingInvalid }],
     ['11 11/22,', 11.5, { allowTrailingInvalid }],
+    ['11__22', 11, { allowTrailingInvalid }],
+    ['11,,22', 11, { allowTrailingInvalid }],
+    ['11,_22', 11, { allowTrailingInvalid }],
+    ['11,_22', 11, { allowTrailingInvalid }],
   ],
   'Trailing invalid characters': [
     ['1 2 3', 1, { allowTrailingInvalid }],

src/types.ts

@@ -23,6 +23,14 @@ export interface NumericQuantityOptions {
    * a valid integer too large for the `number` type.
    */
   bigIntOnOverflow?: boolean;
+  /**
+   * Specifies which character ("." or ",") to treat as the decimal separator.
+   *
+   * @default "."
+   */
+  // TODO: Add support for automatic decimal separator detection
+  // decimalSeparator?: ',' | '.' | 'auto';
+  decimalSeparator?: ',' | '.';
 }
 
 /**

tsconfig.json

@@ -11,8 +11,8 @@
     "esModuleInterop": true,
     "noEmit": true,
     "skipLibCheck": true,
-    "lib": ["ES2015", "DOM"],
-    "target": "es2020"
+    "lib": ["ES2021", "DOM"],
+    "target": "es2021"
   },
   "include": ["./*.ts", "./src"]
 }