Add type definitions for object-map. (#20114)

* Add type definitions for object-map.

* Rename object-map's type variables.

Per suggestion from @plantain-00

* object-map: Declare TThis type for thisArg.

Per suggestion from @andy-ms.

types/object-map/index.d.ts

@@ -0,0 +1,12 @@
+// Type definitions for object-map 1.0
+// Project: https://github.com/xixixao/object-map
+// Definitions by: Wolfgang Faust <https://github.com/wolfgang42>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare function objectMap<TInput, TOutput, TThis>(
+	target: {[k: string]: TInput},
+	callback: (this: TThis, currentValue: TInput, key: string, object: {[k: string]: TInput}) => TOutput,
+	thisArg?: TThis
+): {[k: string]: TOutput};
+
+export = objectMap;

types/object-map/object-map-tests.ts

@@ -0,0 +1,18 @@
+import objectMap = require('object-map');
+
+const obj = {foo: 7, bar: 3, baz: -1};
+
+let total = 0;
+const keys: string[] = [];
+objectMap(obj, (val, key) => {
+	total += val;
+	keys.push(key);
+});
+
+const myThis = {
+	mul: 2,
+	count: 0,
+};
+objectMap(obj, function(val, key) {
+	this.count += this.mul * val;
+}, myThis);

types/object-map/tsconfig.json

@@ -0,0 +1,22 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "object-map-tests.ts"
+    ]
+}

types/object-map/tslint.json

@@ -0,0 +1 @@
+{"extends": "dtslint/dt.json"}