From e555b89f8f54cf1dbd205b5afb572dc8003b4cae Mon Sep 17 00:00:00 2001
From: Alexander Polynomdivision <digitalmail555@googlemail.com>
Date: Fri, 14 Sep 2018 16:55:58 +0200
Subject: [PATCH] fix: Add typings and a test case for equality

---
 src/algorithms/levenshtein/__tests__/levenshtein.test.ts | 5 +++++
 src/algorithms/levenshtein/index.ts                      | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/algorithms/levenshtein/__tests__/levenshtein.test.ts b/src/algorithms/levenshtein/__tests__/levenshtein.test.ts
index d0106de..fd098ce 100644
--- a/src/algorithms/levenshtein/__tests__/levenshtein.test.ts
+++ b/src/algorithms/levenshtein/__tests__/levenshtein.test.ts
@@ -1,5 +1,10 @@
 import { lev, levW } from "../";
 
+test("lev(abc, abc) == 0", () => {
+    expect(lev("abc", "abc", 3, 3)).toBe(0);
+    expect(levW("abc", "abc")).toBe(0);
+});
+
 test("lev(abc, abd) == 1", () => {
     expect(lev("abc", "abd", 3, 3)).toBe(1);
     expect(levW("abc", "abd")).toBe(1);
diff --git a/src/algorithms/levenshtein/index.ts b/src/algorithms/levenshtein/index.ts
index 0810ea1..1405d21 100644
--- a/src/algorithms/levenshtein/index.ts
+++ b/src/algorithms/levenshtein/index.ts
@@ -1,4 +1,4 @@
-export function one(a: string, b: string, i: number, j: number) {
+function one(a: string, b: string, i: number, j: number): number {
     if (a[i] === b[j]) {
         return 0;
     }
@@ -10,7 +10,7 @@ export function one(a: string, b: string, i: number, j: number) {
 // @a, b: The strings to compare
 // @i, j: From where to compare (a_i and b_j)
 // @ret : The distance in insertions, deletions and changes
-export function lev(a: string, b: string, i: number, j: number) {
+export function lev(a: string, b: string, i: number, j: number): number {
     if (Math.min(i, j) === 0) {
         return Math.max(i, j);
     } else {
@@ -25,6 +25,6 @@ export function lev(a: string, b: string, i: number, j: number) {
 // Computes the difference between the strings a and b.
 // @a, b: The strings to compare
 // @ret : The distance in insertions, deletions and changes
-export function levW(a: string, b: string) {
+export function levW(a: string, b: string): number {
     return lev(a, b, a.length, b.length);
 }