Create a type definition for npm module hark (#38375)

* Create a type definition for npm module hark

* Update index.d.ts

* Update index.d.ts

types/hark/hark-tests.ts

@@ -0,0 +1,22 @@
+import hark = require('hark');
+
+navigator.mediaDevices.getUserMedia({ audio: true, video: true }).then(
+    (stream) => {
+        const option: hark.Option = {
+            smoothing: 0.1,
+            interval: 50,
+            history: 10,
+            threshold: -50
+        };
+        const h: hark.Harker = hark(stream, option);
+        h.stop();
+        h.resume();
+        h.on('speaking', () => {
+            console.log('speaking');
+        });
+
+        h.on('stopped_speaking', () => {
+            console.log('stop speaking');
+        });
+    }
+);

types/hark/index.d.ts

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+// Type definitions for hark 1.2
+// Project: https://github.com/otalk/hark
+// Definitions by: baiyufei <https://github.com/baiyufei>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+export = hark;
+
+declare function hark(stream: HTMLAudioElement | HTMLVideoElement | MediaStream, option?: hark.Option): hark.Harker;
+
+declare namespace hark {
+    interface Option {
+        smoothing?: number;
+        interval?: number;
+        threshold?: number;
+        play?: boolean;
+        history?: number;
+    }
+
+    interface Harker {
+        speaking: boolean;
+        suspend(): Promise<void>;
+        resume(): Promise<void>;
+        readonly state: AudioContextState;
+        setThreshold(t: number): void;
+        setInterval(i: number): void;
+        stop(): void;
+        speakingHistory: number[];
+
+        on(event: 'speaking' | 'stopped_speaking', listener: () => void): void;
+        on(event: 'volume_change', listener: (currentVolume: number, threshold: number) => void): void;
+        on(event: 'state_change', listener: (state: AudioContextState) => void): void;
+    }
+}

types/hark/tsconfig.json

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+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6", "dom"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "hark-tests.ts"
+    ]
+}

types/hark/tslint.json

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