From 37840a3ba3dd98d035ab904555e3d1edd6484ac3 Mon Sep 17 00:00:00 2001
From: cgjgh <160297365+cgjgh@users.noreply.github.com>
Date: Thu, 13 Mar 2025 15:39:03 -0500
Subject: [PATCH] Added Dutch, French, Italian and Spanish languages

---
 .changeset/tricky-streets-accept.md |  5 ++
 README.md                           |  4 ++
 src/languages/es.ts                 | 72 +++++++++++++++++++++++++++++
 src/languages/fr.ts                 | 72 +++++++++++++++++++++++++++++
 src/languages/index.ts              |  8 +++-
 src/languages/it.ts                 | 72 +++++++++++++++++++++++++++++
 src/languages/nl.ts                 | 72 +++++++++++++++++++++++++++++
 tests/de.test.ts                    | 58 +++++++++++++++++++++++
 tests/es.test.ts                    | 56 ++++++++++++++++++++++
 tests/fr.test.ts                    | 56 ++++++++++++++++++++++
 tests/it.test.ts                    | 57 +++++++++++++++++++++++
 tests/nl.test.ts                    | 56 ++++++++++++++++++++++
 12 files changed, 586 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/tricky-streets-accept.md
 create mode 100644 src/languages/es.ts
 create mode 100644 src/languages/fr.ts
 create mode 100644 src/languages/it.ts
 create mode 100644 src/languages/nl.ts
 create mode 100644 tests/de.test.ts
 create mode 100644 tests/es.test.ts
 create mode 100644 tests/fr.test.ts
 create mode 100644 tests/it.test.ts
 create mode 100644 tests/nl.test.ts

diff --git a/.changeset/tricky-streets-accept.md b/.changeset/tricky-streets-accept.md
new file mode 100644
index 0000000..225e6b1
--- /dev/null
+++ b/.changeset/tricky-streets-accept.md
@@ -0,0 +1,5 @@
+---
+"enhanced-ms": minor
+---
+
+Added language support for Dutch, French, Italian and Spanish
diff --git a/README.md b/README.md
index df2d581..fdbaf57 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,10 @@ The currently supported languages include:
 | German            | de  |
 | Russian           | ru  |
 | Māori             | mi  |
+| Spanish           | es  |
+| Dutch             | nl  |
+| Italian           | it  |
+| French            | fr  |
 
 You can help by adding support for more languages.
 
diff --git a/src/languages/es.ts b/src/languages/es.ts
new file mode 100644
index 0000000..179eb2c
--- /dev/null
+++ b/src/languages/es.ts
@@ -0,0 +1,72 @@
+export default {
+  decimal: ',',
+  and: 'y',
+
+  units: {
+    nanosecond: {
+      name: (c) => (c === 1 ? 'nanosegundo' : 'nanosegundos'),
+      abbreviation: 'ns',
+      matches: ['nanosegundo', 'nanosegundos', 'ns'],
+    },
+    microsecond: {
+      name: (c) => (c === 1 ? 'microsegundo' : 'microsegundos'),
+      abbreviation: 'μs',
+      matches: ['microsegundo', 'microsegundos', 'μs'],
+    },
+    millisecond: {
+      name: (c) => (c === 1 ? 'milisegundo' : 'milisegundos'),
+      abbreviation: 'ms',
+      matches: ['milisegundo', 'milisegundos', 'ms'],
+    },
+    second: {
+      name: (c) => (c === 1 ? 'segundo' : 'segundos'),
+      abbreviation: 's',
+      matches: ['segundo', 'segundos', 's'],
+    },
+    minute: {
+      name: (c) => (c === 1 ? 'minuto' : 'minutos'),
+      abbreviation: 'min',
+      matches: ['minuto', 'minutos', 'min'],
+    },
+    hour: {
+      name: (c) => (c === 1 ? 'hora' : 'horas'),
+      abbreviation: 'h',
+      matches: ['hora', 'horas', 'h'],
+    },
+    day: {
+      name: (c) => (c === 1 ? 'día' : 'días'),
+      abbreviation: 'd',
+      matches: ['día', 'días', 'd'],
+    },
+    week: {
+      name: (c) => (c === 1 ? 'semana' : 'semanas'),
+      abbreviation: 'sem',
+      matches: ['semana', 'semanas', 'sem'],
+    },
+    month: {
+      name: (c) => (c === 1 ? 'mes' : 'meses'),
+      abbreviation: 'mes',
+      matches: ['mes', 'meses', 'mes'],
+    },
+    year: {
+      name: (c) => (c === 1 ? 'año' : 'años'),
+      abbreviation: 'a',
+      matches: ['año', 'años', 'a'],
+    },
+    decade: {
+      name: (c) => (c === 1 ? 'década' : 'décadas'),
+      abbreviation: 'déc',
+      matches: ['década', 'décadas', 'déc'],
+    },
+    century: {
+      name: (c) => (c === 1 ? 'siglo' : 'siglos'),
+      abbreviation: 'sig',
+      matches: ['siglo', 'siglos', 'sig'],
+    },
+    millennium: {
+      name: (c) => (c === 1 ? 'milenio' : 'milenios'),
+      abbreviation: 'mil',
+      matches: ['milenio', 'milenios', 'mil'],
+    },
+  },
+} satisfies import('./helpers/definition-types').LanguageDefinition;
diff --git a/src/languages/fr.ts b/src/languages/fr.ts
new file mode 100644
index 0000000..373b1f9
--- /dev/null
+++ b/src/languages/fr.ts
@@ -0,0 +1,72 @@
+export default {
+  decimal: ',',
+  and: 'et',
+
+  units: {
+    nanosecond: {
+      name: (c) => (c === 1 ? 'nanoseconde' : 'nanosecondes'),
+      abbreviation: 'ns',
+      matches: ['nanoseconde', 'nanosecondes', 'ns'],
+    },
+    microsecond: {
+      name: (c) => (c === 1 ? 'microseconde' : 'microsecondes'),
+      abbreviation: 'μs',
+      matches: ['microseconde', 'microsecondes', 'μs'],
+    },
+    millisecond: {
+      name: (c) => (c === 1 ? 'milliseconde' : 'millisecondes'),
+      abbreviation: 'ms',
+      matches: ['milliseconde', 'millisecondes', 'ms'],
+    },
+    second: {
+      name: (c) => (c === 1 ? 'seconde' : 'secondes'),
+      abbreviation: 's',
+      matches: ['seconde', 'secondes', 's'],
+    },
+    minute: {
+      name: (c) => (c === 1 ? 'minute' : 'minutes'),
+      abbreviation: 'min',
+      matches: ['minute', 'minutes', 'min'],
+    },
+    hour: {
+      name: (c) => (c === 1 ? 'heure' : 'heures'),
+      abbreviation: 'h',
+      matches: ['heure', 'heures', 'h'],
+    },
+    day: {
+      name: (c) => (c === 1 ? 'jour' : 'jours'),
+      abbreviation: 'j',
+      matches: ['jour', 'jours', 'j'],
+    },
+    week: {
+      name: (c) => (c === 1 ? 'semaine' : 'semaines'),
+      abbreviation: 'sem',
+      matches: ['semaine', 'semaines', 'sem'],
+    },
+    month: {
+      name: (_c) => 'mois', // In French, the singular and plural form is identical.
+      abbreviation: 'mo',
+      matches: ['mois', 'mo'],
+    },
+    year: {
+      name: (c) => (c === 1 ? 'an' : 'ans'),
+      abbreviation: 'an',
+      matches: ['an', 'ans'],
+    },
+    decade: {
+      name: (c) => (c === 1 ? 'décennie' : 'décennies'),
+      abbreviation: 'dec',
+      matches: ['décennie', 'décennies', 'dec'],
+    },
+    century: {
+      name: (c) => (c === 1 ? 'siècle' : 'siècles'),
+      abbreviation: 'siè',
+      matches: ['siècle', 'siècles', 'siè'],
+    },
+    millennium: {
+      name: (c) => (c === 1 ? 'millénaire' : 'millénaires'),
+      abbreviation: 'mil',
+      matches: ['millénaire', 'millénaires', 'mil'],
+    },
+  },
+} satisfies import('./helpers/definition-types').LanguageDefinition;
diff --git a/src/languages/index.ts b/src/languages/index.ts
index 17390da..3018c0c 100644
--- a/src/languages/index.ts
+++ b/src/languages/index.ts
@@ -2,10 +2,14 @@ import type { LanguageDefinition } from './helpers/definition-types';
 
 import de from './de';
 import en from './en';
+import es from './es';
+import fr from './fr';
+import it from './it';
 import mi from './mi';
+import nl from './nl';
 import ru from './ru';
 
 // This prevents the whole language definition being included in the dts output
-type Locale = 'de' | 'en' | 'mi' | 'ru';
+type Locale = 'de' | 'en' | 'es' | 'fr' | 'it' | 'mi' | 'nl' | 'ru';
 type Languages = Record<Locale, LanguageDefinition>;
-export const languages: Languages = { de, en, mi, ru };
+export const languages: Languages = { de, en, es, fr, it, mi, nl, ru };
diff --git a/src/languages/it.ts b/src/languages/it.ts
new file mode 100644
index 0000000..91d08c9
--- /dev/null
+++ b/src/languages/it.ts
@@ -0,0 +1,72 @@
+export default {
+  decimal: ',',
+  and: 'e',
+
+  units: {
+    nanosecond: {
+      name: (c) => (c === 1 ? 'nanosecondo' : 'nanosecondi'),
+      abbreviation: 'ns',
+      matches: ['nanosecondo', 'nanosecondi', 'ns'],
+    },
+    microsecond: {
+      name: (c) => (c === 1 ? 'microsecondo' : 'microsecondi'),
+      abbreviation: 'μs',
+      matches: ['microsecondo', 'microsecondi', 'μs'],
+    },
+    millisecond: {
+      name: (c) => (c === 1 ? 'millisecondo' : 'millisecondi'),
+      abbreviation: 'ms',
+      matches: ['millisecondo', 'millisecondi', 'ms'],
+    },
+    second: {
+      name: (c) => (c === 1 ? 'secondo' : 'secondi'),
+      abbreviation: 's',
+      matches: ['secondo', 'secondi', 's'],
+    },
+    minute: {
+      name: (c) => (c === 1 ? 'minuto' : 'minuti'),
+      abbreviation: 'min',
+      matches: ['minuto', 'minuti', 'min'],
+    },
+    hour: {
+      name: (c) => (c === 1 ? 'ora' : 'ore'),
+      abbreviation: 'h',
+      matches: ['ora', 'ore', 'h'],
+    },
+    day: {
+      name: (c) => (c === 1 ? 'giorno' : 'giorni'),
+      abbreviation: 'g',
+      matches: ['giorno', 'giorni', 'g'],
+    },
+    week: {
+      name: (c) => (c === 1 ? 'settimana' : 'settimane'),
+      abbreviation: 'sett',
+      matches: ['settimana', 'settimane', 'sett'],
+    },
+    month: {
+      name: (c) => (c === 1 ? 'mese' : 'mesi'),
+      abbreviation: 'mes',
+      matches: ['mese', 'mesi', 'mes'],
+    },
+    year: {
+      name: (c) => (c === 1 ? 'anno' : 'anni'),
+      abbreviation: 'a',
+      matches: ['anno', 'anni', 'a'],
+    },
+    decade: {
+      name: (c) => (c === 1 ? 'decennio' : 'decenni'),
+      abbreviation: 'dec',
+      matches: ['decennio', 'decenni', 'dec'],
+    },
+    century: {
+      name: (c) => (c === 1 ? 'secolo' : 'secoli'),
+      abbreviation: 'sc',
+      matches: ['secolo', 'secoli', 'sc'],
+    },
+    millennium: {
+      name: (c) => (c === 1 ? 'millennio' : 'millenni'),
+      abbreviation: 'mil',
+      matches: ['millennio', 'millenni', 'mil'],
+    },
+  },
+} satisfies import('./helpers/definition-types').LanguageDefinition;
diff --git a/src/languages/nl.ts b/src/languages/nl.ts
new file mode 100644
index 0000000..2d3166e
--- /dev/null
+++ b/src/languages/nl.ts
@@ -0,0 +1,72 @@
+export default {
+  decimal: ',',
+  and: 'en',
+
+  units: {
+    nanosecond: {
+      name: (c) => (c === 1 ? 'nanoseconde' : 'nanoseconden'),
+      abbreviation: 'ns',
+      matches: ['nanoseconde', 'nanoseconden', 'ns'],
+    },
+    microsecond: {
+      name: (c) => (c === 1 ? 'microseconde' : 'microseconden'),
+      abbreviation: 'μs',
+      matches: ['microseconde', 'microseconden', 'μs'],
+    },
+    millisecond: {
+      name: (c) => (c === 1 ? 'milliseconde' : 'milliseconden'),
+      abbreviation: 'ms',
+      matches: ['milliseconde', 'milliseconden', 'ms'],
+    },
+    second: {
+      name: (c) => (c === 1 ? 'seconde' : 'seconden'),
+      abbreviation: 's',
+      matches: ['seconde', 'seconden', 's'],
+    },
+    minute: {
+      name: (c) => (c === 1 ? 'minuut' : 'minuten'),
+      abbreviation: 'min',
+      matches: ['minuut', 'minuten', 'min'],
+    },
+    hour: {
+      name: (c) => (c === 1 ? 'uur' : 'uren'),
+      abbreviation: 'h',
+      matches: ['uur', 'uren', 'h'],
+    },
+    day: {
+      name: (c) => (c === 1 ? 'dag' : 'dagen'),
+      abbreviation: 'd',
+      matches: ['dag', 'dagen', 'd'],
+    },
+    week: {
+      name: (c) => (c === 1 ? 'week' : 'weken'),
+      abbreviation: 'w',
+      matches: ['week', 'weken', 'w'],
+    },
+    month: {
+      name: (c) => (c === 1 ? 'maand' : 'maanden'),
+      abbreviation: 'mnd',
+      matches: ['maand', 'maanden', 'mnd'],
+    },
+    year: {
+      name: (c) => (c === 1 ? 'jaar' : 'jaren'),
+      abbreviation: 'jr',
+      matches: ['jaar', 'jaren', 'jr'],
+    },
+    decade: {
+      name: (c) => (c === 1 ? 'decennium' : 'decennia'),
+      abbreviation: 'dec',
+      matches: ['decennium', 'decennia', 'dec'],
+    },
+    century: {
+      name: (c) => (c === 1 ? 'eeuw' : 'eeuwen'),
+      abbreviation: 'eeuw',
+      matches: ['eeuw', 'eeuwen'],
+    },
+    millennium: {
+      name: (c) => (c === 1 ? 'millennium' : 'millennia'),
+      abbreviation: 'mil',
+      matches: ['millennium', 'millennia', 'mil'],
+    },
+  },
+} satisfies import('./helpers/definition-types').LanguageDefinition;
diff --git a/tests/de.test.ts b/tests/de.test.ts
new file mode 100644
index 0000000..ce02cb2
--- /dev/null
+++ b/tests/de.test.ts
@@ -0,0 +1,58 @@
+import { createMs } from 'enhanced-ms';
+import { describe, expect, it } from 'vitest';
+
+// Using German locale (de)
+const ms = createMs({ language: 'de' });
+
+describe('German (Deutsch)', () => {
+  describe('format milliseconds', () => {
+    it('formats with default options', () => {
+      // 90061 ms should format as "1 Minute 30 Sekunden"
+      expect(ms(90061)).toBe('1 Minute 30 Sekunden');
+      // 90061000 ms should format as "1 Tag 1 Stunde 1 Minute 1 Sekunde"
+      expect(ms(90061000)).toBe('1 Tag 1 Stunde 1 Minute 1 Sekunde');
+    });
+
+    it('returns null for durations below one second with default options', () => {
+      expect(ms(0)).toBeNull();
+    });
+
+    it('formats with preset short', () => {
+      // Expected abbreviations based on the German config:
+      // Minute -> "Min.", Sekunde -> "Sek.", Tag -> "T.", Stunde -> "Std."
+      expect(ms(90061, 'short')).toBe('1Min. 30Sek.');
+      expect(ms(90061000, 'short')).toBe('1T. 1Std.');
+    });
+
+    it('formats with colon notation preset', () => {
+      expect(ms(90061, 'colonNotation')).toBe('01:30');
+      expect(ms(90061000, 'colonNotation')).toBe('25:01:01');
+    });
+
+    it('formats with use abbreviations', () => {
+      const options = { useAbbreviations: true };
+      expect(ms(90061, options)).toBe('1Min. 30Sek.');
+      expect(ms(90061000, options)).toBe('1T. 1Std. 1Min. 1Sek.');
+    });
+
+    it('formats with a unit limit', () => {
+      const options = { unitLimit: 1 };
+      expect(ms(90061, options)).toBe('1 Minute');
+      expect(ms(90061000, options)).toBe('1 Tag');
+    });
+  });
+
+  describe('parse duration', () => {
+    it('parses durations correctly', () => {
+      expect(ms('1 Minute 30 Sekunden')).toBe(90000);
+      expect(ms('1Min. 30Sek.')).toBe(90000);
+      expect(ms('1 Minute 30 Sekunden 61 Millisekunden')).toBe(90061);
+      expect(ms('1Min. 30Sek. 61ms')).toBe(90061);
+    });
+
+    it('returns zero for invalid duration strings', () => {
+      expect(ms('nyr9341')).toBe(0);
+      expect(ms('o4utrc89nyt')).toBe(0);
+    });
+  });
+});
diff --git a/tests/es.test.ts b/tests/es.test.ts
new file mode 100644
index 0000000..5e27fa9
--- /dev/null
+++ b/tests/es.test.ts
@@ -0,0 +1,56 @@
+import { createMs } from 'enhanced-ms';
+import { describe, expect, it } from 'vitest';
+
+const ms = createMs({ language: 'es' });
+
+describe('Spanish (Español)', () => {
+  describe('format milliseconds', () => {
+    it('formats with default options', () => {
+      // 90061 ms should format as "1 minuto 30 segundos" in Spanish
+      expect(ms(90061)).toBe('1 minuto 30 segundos');
+      // 90061000 ms should format as "1 día 1 hora 1 minuto 1 segundo" in Spanish
+      expect(ms(90061000)).toBe('1 día 1 hora 1 minuto 1 segundo');
+    });
+
+    it('returns null for durations below one second with default options', () => {
+      expect(ms(0)).toBeNull();
+    });
+
+    it('formats with preset short', () => {
+      // Expected abbreviations: "min" for minuto, "s" for segundo, "d" for día, "h" for hora.
+      expect(ms(90061, 'short')).toBe('1min 30s');
+      expect(ms(90061000, 'short')).toBe('1d 1h');
+    });
+
+    it('formats with colon notation preset', () => {
+      expect(ms(90061, 'colonNotation')).toBe('01:30');
+      expect(ms(90061000, 'colonNotation')).toBe('25:01:01');
+    });
+
+    it('formats with use abbreviations', () => {
+      const options = { useAbbreviations: true };
+      expect(ms(90061, options)).toBe('1min 30s');
+      expect(ms(90061000, options)).toBe('1d 1h 1min 1s');
+    });
+
+    it('formats with a unit limit', () => {
+      const options = { unitLimit: 1 };
+      expect(ms(90061, options)).toBe('1 minuto');
+      expect(ms(90061000, options)).toBe('1 día');
+    });
+  });
+
+  describe('parse duration', () => {
+    it('parses durations correctly', () => {
+      expect(ms('1 minuto 30 segundos')).toBe(90000);
+      expect(ms('1min 30s')).toBe(90000);
+      expect(ms('1 minuto 30 segundos 61 milisegundos')).toBe(90061);
+      expect(ms('1min 30s 61ms')).toBe(90061);
+    });
+
+    it('returns zero for invalid duration strings', () => {
+      expect(ms('nyr9341')).toBe(0);
+      expect(ms('o4utrc89nyt')).toBe(0);
+    });
+  });
+});
diff --git a/tests/fr.test.ts b/tests/fr.test.ts
new file mode 100644
index 0000000..5b28e25
--- /dev/null
+++ b/tests/fr.test.ts
@@ -0,0 +1,56 @@
+import { createMs } from 'enhanced-ms';
+import { describe, expect, it } from 'vitest';
+
+const ms = createMs({ language: 'fr' });
+
+describe('French (Français)', () => {
+  describe('format milliseconds', () => {
+    it('formats with default options', () => {
+      // 90061 ms should format as "1 minute 30 secondes" in French
+      expect(ms(90061)).toBe('1 minute 30 secondes');
+      // 90061000 ms should format as "1 jour 1 heure 1 minute 1 seconde" in French
+      expect(ms(90061000)).toBe('1 jour 1 heure 1 minute 1 seconde');
+    });
+
+    it('returns null for durations below one second with default options', () => {
+      expect(ms(0)).toBeNull();
+    });
+
+    it('formats with preset short', () => {
+      // Expected short format using abbreviations: "min" for minute, "s" for seconde, "j" for jour, "h" for heure.
+      expect(ms(90061, 'short')).toBe('1min 30s');
+      expect(ms(90061000, 'short')).toBe('1j 1h');
+    });
+
+    it('formats with colon notation preset', () => {
+      expect(ms(90061, 'colonNotation')).toBe('01:30');
+      expect(ms(90061000, 'colonNotation')).toBe('25:01:01');
+    });
+
+    it('formats with use abbreviations', () => {
+      const options = { useAbbreviations: true };
+      expect(ms(90061, options)).toBe('1min 30s');
+      expect(ms(90061000, options)).toBe('1j 1h 1min 1s');
+    });
+
+    it('formats with a unit limit', () => {
+      const options = { unitLimit: 1 };
+      expect(ms(90061, options)).toBe('1 minute');
+      expect(ms(90061000, options)).toBe('1 jour');
+    });
+  });
+
+  describe('parse duration', () => {
+    it('parses durations correctly', () => {
+      expect(ms('1 minute 30 secondes')).toBe(90000);
+      expect(ms('1min 30s')).toBe(90000);
+      expect(ms('1 minute 30 secondes 61 millisecondes')).toBe(90061);
+      expect(ms('1min 30s 61ms')).toBe(90061);
+    });
+
+    it('returns zero for invalid duration strings', () => {
+      expect(ms('nyr9341')).toBe(0);
+      expect(ms('o4utrc89nyt')).toBe(0);
+    });
+  });
+});
diff --git a/tests/it.test.ts b/tests/it.test.ts
new file mode 100644
index 0000000..44234de
--- /dev/null
+++ b/tests/it.test.ts
@@ -0,0 +1,57 @@
+import { createMs } from 'enhanced-ms';
+import { describe, expect, it } from 'vitest';
+
+const ms = createMs({ language: 'it' });
+
+describe('Italian (Italiano)', () => {
+  describe('format milliseconds', () => {
+    it('formats with default options', () => {
+      // 90061 ms should format as "1 minuto 30 secondi" in Italian.
+      expect(ms(90061)).toBe('1 minuto 30 secondi');
+      // 90061000 ms should format as "1 giorno 1 ora 1 minuto 1 secondo" in Italian.
+      expect(ms(90061000)).toBe('1 giorno 1 ora 1 minuto 1 secondo');
+    });
+
+    it('returns null for durations below one second with default options', () => {
+      expect(ms(0)).toBeNull();
+    });
+
+    it('formats with preset short', () => {
+      // Expected abbreviations: "min" for minuto, "s" for secondi,
+      // "g" for giorno, "h" for ora.
+      expect(ms(90061, 'short')).toBe('1min 30s');
+      expect(ms(90061000, 'short')).toBe('1g 1h');
+    });
+
+    it('formats with colon notation preset', () => {
+      expect(ms(90061, 'colonNotation')).toBe('01:30');
+      expect(ms(90061000, 'colonNotation')).toBe('25:01:01');
+    });
+
+    it('formats with use abbreviations', () => {
+      const options = { useAbbreviations: true };
+      expect(ms(90061, options)).toBe('1min 30s');
+      expect(ms(90061000, options)).toBe('1g 1h 1min 1s');
+    });
+
+    it('formats with a unit limit', () => {
+      const options = { unitLimit: 1 };
+      expect(ms(90061, options)).toBe('1 minuto');
+      expect(ms(90061000, options)).toBe('1 giorno');
+    });
+  });
+
+  describe('parse duration', () => {
+    it('parses durations correctly', () => {
+      expect(ms('1 minuto 30 secondi')).toBe(90000);
+      expect(ms('1min 30s')).toBe(90000);
+      expect(ms('1 minuto 30 secondi 61 millisecondi')).toBe(90061);
+      expect(ms('1min 30s 61ms')).toBe(90061);
+    });
+
+    it('returns zero for invalid duration strings', () => {
+      expect(ms('nyr9341')).toBe(0);
+      expect(ms('o4utrc89nyt')).toBe(0);
+    });
+  });
+});
diff --git a/tests/nl.test.ts b/tests/nl.test.ts
new file mode 100644
index 0000000..b742818
--- /dev/null
+++ b/tests/nl.test.ts
@@ -0,0 +1,56 @@
+import { createMs } from 'enhanced-ms';
+import { describe, expect, it } from 'vitest';
+
+const ms = createMs({ language: 'nl' });
+
+describe('Dutch (Nederlands)', () => {
+  describe('format milliseconds', () => {
+    it('formats with default options', () => {
+      // 90061 ms should format as "1 minuut 30 seconden" in Dutch.
+      expect(ms(90061)).toBe('1 minuut 30 seconden');
+      // 90061000 ms should format as "1 dag 1 uur 1 minuut 1 seconde" in Dutch.
+      expect(ms(90061000)).toBe('1 dag 1 uur 1 minuut 1 seconde');
+    });
+
+    it('returns null for durations below one second with default options', () => {
+      expect(ms(0)).toBeNull();
+    });
+
+    it('formats with preset short', () => {
+      // Expected short format: "min" for minuut, "s" for seconde, "d" for dag, "h" for uur.
+      expect(ms(90061, 'short')).toBe('1min 30s');
+      expect(ms(90061000, 'short')).toBe('1d 1h');
+    });
+
+    it('formats with colon notation preset', () => {
+      expect(ms(90061, 'colonNotation')).toBe('01:30');
+      expect(ms(90061000, 'colonNotation')).toBe('25:01:01');
+    });
+
+    it('formats with use abbreviations', () => {
+      const options = { useAbbreviations: true };
+      expect(ms(90061, options)).toBe('1min 30s');
+      expect(ms(90061000, options)).toBe('1d 1h 1min 1s');
+    });
+
+    it('formats with a unit limit', () => {
+      const options = { unitLimit: 1 };
+      expect(ms(90061, options)).toBe('1 minuut');
+      expect(ms(90061000, options)).toBe('1 dag');
+    });
+  });
+
+  describe('parse duration', () => {
+    it('parses durations correctly', () => {
+      expect(ms('1 minuut 30 seconden')).toBe(90000);
+      expect(ms('1min 30s')).toBe(90000);
+      expect(ms('1 minuut 30 seconden 61 milliseconden')).toBe(90061);
+      expect(ms('1min 30s 61ms')).toBe(90061);
+    });
+
+    it('returns zero for invalid duration strings', () => {
+      expect(ms('nyr9341')).toBe(0);
+      expect(ms('o4utrc89nyt')).toBe(0);
+    });
+  });
+});