Levenshtein Typings [Types-2.0] (#11965)

* Adding Levenshtein typings

* Strict null checks on levenshtein

levenshtein/index.d.ts

@@ -0,0 +1,47 @@
+// Type definitions for levenshtein v1.0
+// Project: https://github.com/gf3/Levenshtein
+// Definitions by: Joshua DeVinney <https://github.com/geoffreak>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare class Levenshtein {
+    /**
+     * Levenshtein string difference
+     * @param m First string
+     * @param n Second string
+     */
+    constructor(m: string, n: string);
+
+    /**
+     * Distance between strings
+     */
+    distance: number;
+
+    /**
+     * Distance between strings
+     * Alias of distance
+     */
+    valueOf(): number;
+
+    /**
+     * Pretty print Levenshtein table.
+     */
+    inspect(): string;
+
+    /**
+     * Pretty print Levenshtein table.
+     * Alias of inspect()
+     */
+    toString(): string;
+
+    /**
+     * Return the Levenshtein table.
+     */
+    getMatrix(): number[][];
+}
+
+// Required to make import as syntax work
+declare namespace Levenshtein {
+
+}
+
+export = Levenshtein;

levenshtein/levenshtein-tests.ts

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+import * as Levenshtein from 'levenshtein';
+
+// Using standard methods
+let l1 = new Levenshtein('kitten', 'sitting');
+let num1: number = l1.distance;
+let str1: string = l1.inspect();
+
+// Using alias methods
+let l2 = new Levenshtein('Saturday', 'Sunday');
+let num2: number = l2.valueOf();
+let str2: string = l2.toString();
+
+// Levenshtein matrix can be retrieved
+let l3 = new Levenshtein('kitten', 'sitting');
+l3.getMatrix()[0].length;

levenshtein/tsconfig.json

@@ -0,0 +1,19 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "target": "es6",
+        "noImplicitAny": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "levenshtein-tests.ts"
+    ]
+}