A Letter's Best Friend

Given a string, return if a given letter always appears immediately before another given letter.

Worked Example

bestFriend("he headed to the store", "h", "e") ➞ true

// All occurences of "h": ["he", "headed", "the"]
// All occurences of "h" have an "e" after it.
// Return true

Examples

bestFriend("he headed to the store", "h", "e") ➞ true

bestFriend("i found an ounce with my hound", "o", "u") ➞ true

bestFriend("we found your dynamite", "d", "y") ➞ false

Notes

• Don't count letters with spaces between them (example #3).
• All sentences will be given in lowercase.