--- /dev/null
+'use strict'
+
+module.exports = longestStreak
+
+// Get the count of the longest repeating streak of `character` in `value`.
+function longestStreak(value, character) {
+ var count = 0
+ var maximum = 0
+ var expected
+ var index
+
+ if (typeof character !== 'string' || character.length !== 1) {
+ throw new Error('Expected character')
+ }
+
+ value = String(value)
+ index = value.indexOf(character)
+ expected = index
+
+ while (index !== -1) {
+ count++
+
+ if (index === expected) {
+ if (count > maximum) {
+ maximum = count
+ }
+ } else {
+ count = 1
+ }
+
+ expected = index + 1
+ index = value.indexOf(character, expected)
+ }
+
+ return maximum
+}