Add string-hash (#12499)

Refactor string-hash definition

Refactor string-hash to use commonjs

string-hash/index.d.ts

@@ -0,0 +1,8 @@
+// Type definitions for string-hash 1.1.1
+// Project: https://github.com/darkskyapp/string-hash
+// Definitions by: Ethan Rubio <https://github.com/ethanrubio/>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare function stringHash(str: string): number;
+
+export = stringHash;

string-hash/string-hash-tests.ts

@@ -0,0 +1,3 @@
+import hash = require("string-hash");
+
+const newHash: number = hash("Mary had a little lamb."); // 1766333550

string-hash/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",
+        "string-hash-tests.ts"
+    ]
+}