Expose character count countFunctions

Author: colinrotherham

packages/nhsuk-frontend/src/nhsuk/components/character-count/character-count.mjs

@@ -211,20 +211,11 @@ export class CharacterCount extends ConfigurableComponent {
    * @param {string} [text] - Deprecated
    */
   updateCount(text) {
-    const { $textarea } = this
-    const { countType } = this.config
+    const { $textarea, countFunctions } = this
+    const { countType = 'length' } = this.config
 
-    text = text ?? $textarea.value
-
-    if (countType === 'words') {
-      const tokens = text.match(/\S+/g) ?? [] // Matches consecutive non-whitespace chars
-      this.length = tokens.length
-      return
-    }
-
-    this.length = this.segmenter
-      ? Array.from(this.segmenter.segment(text)).length
-      : text.length
+    text ??= $textarea.value
+    this.length = countFunctions[countType].call(this, text)
   }
 
   /**
@@ -447,6 +438,30 @@ export class CharacterCount extends ConfigurableComponent {
     }
   }
 
+  /**
+   * Character count functions
+   *
+   * @constant
+   * @satisfies {Record<string, (this: CharacterCount, text: string) => number>}
+   */
+  countFunctions = Object.freeze({
+    length(text) {
+      return text.length
+    },
+    characters(text) {
+      if (!this.segmenter) {
+        return text.length
+      }
+
+      const segments = Array.from(this.segmenter.segment(text))
+      return segments.length
+    },
+    words(text) {
+      const tokens = text.match(/\S+/g) ?? [] // Matches consecutive non-whitespace chars
+      return tokens.length
+    }
+  })
+
   /**
    * Name for the component used when initialising using data-module attributes
    */
@@ -548,7 +563,7 @@ export function initCharacterCounts(options) {
  * @property {number} [maxwords] - Deprecated. Use `maxlength` and `countType: "words"` instead.
  * @property {number} [threshold=0] - The percentage value of the limit at which point the count message is displayed.
  *   If this attribute is set, the count message will be hidden by default.
- * @property {'characters' | 'words'} [countType] - The count type (`"characters"` or `"words"`) used to count the text.
+ * @property {'length' | 'characters' | 'words'} [countType] - The count type (`"characters"` or `"words"`) used to count the text.
  * @property {string} textareaDescriptionClass - Textarea description class
  * @property {string} visibleCountMessageClass - Visible count message class
  * @property {string} screenReaderCountMessageClass - Screen reader count message class