feat: slugify filter from Jekyll, #443

src/filters/url.ts

@@ -8,3 +8,44 @@ export const cgi_escape = (x: string) => encodeURIComponent(stringify(x))
 export const uri_escape = (x: string) => encodeURI(stringify(x))
   .replace(/%5B/g, '[')
   .replace(/%5D/g, ']')
+
+const rSlugifyDefault = /[^\p{M}\p{L}\p{Nd}]+/ug
+const rSlugifyReplacers = {
+  'raw': /\s+/g,
+  'default': rSlugifyDefault,
+  'pretty': /[^\p{M}\p{L}\p{Nd}._~!$&'()+,;=@]+/ug,
+  'ascii': /[^A-Za-z0-9]+/g,
+  'latin': rSlugifyDefault,
+  'none': null
+}
+
+export function slugify (str: string, mode: keyof typeof rSlugifyReplacers = 'default', cased = false): string {
+  str = stringify(str)
+
+  const replacer = rSlugifyReplacers[mode]
+  if (replacer) {
+    if (mode === 'latin') str = removeAccents(str)
+    str = str.replace(replacer, '-').replace(/^-|-$/g, '')
+  }
+
+  return cased ? str : str.toLowerCase()
+}
+
+function removeAccents (str: string): string {
+  return str.replace(/[àáâãäå]/g, 'a')
+    .replace(/[æ]/g, 'ae')
+    .replace(/[ç]/g, 'c')
+    .replace(/[èéêë]/g, 'e')
+    .replace(/[ìíîï]/g, 'i')
+    .replace(/[ð]/g, 'd')
+    .replace(/[ñ]/g, 'n')
+    .replace(/[òóôõöø]/g, 'o')
+    .replace(/[ùúûü]/g, 'u')
+    .replace(/[ýÿ]/g, 'y')
+    .replace(/[ß]/g, 'ss')
+    .replace(/[œ]/g, 'oe')
+    .replace(/[þ]/g, 'th')
+    .replace(/[ẞ]/g, 'SS')
+    .replace(/[Œ]/g, 'OE')
+    .replace(/[Þ]/g, 'TH')
+}