checkCallbackFnOrThrow

Author: odahcam

src/readers/BrowserCodeReader.ts

@@ -512,6 +512,23 @@ export class BrowserCodeReader {
     });
   }
 
+  /**
+   * Checks if the `callbackFn` is defined, otherwise throws.
+   */
+  private static checkCallbackFnOrThrow(callbackFn: DecodeContinuouslyCallback) {
+    if (!callbackFn) {
+      throw new ArgumentException('`callbackFn` is a required parameter, you cannot capture results without it.');
+    }
+  }
+
+  /**
+   * Standard method to dispose a media stream object.
+   */
+  private static disposeMediaStream(stream: MediaStream) {
+    stream.getVideoTracks().forEach((x) => x.stop());
+    stream = undefined;
+  }
+
   /**
    * BrowserCodeReader specific configuration options.
    */
@@ -614,6 +631,8 @@ export class BrowserCodeReader {
     callbackFn: DecodeContinuouslyCallback,
   ): Promise<IScannerControls> {
 
+    BrowserCodeReader.checkCallbackFnOrThrow(callbackFn);
+
     const stream = await navigator.mediaDevices.getUserMedia(constraints);
 
     try {
@@ -639,6 +658,8 @@ export class BrowserCodeReader {
     callbackFn: DecodeContinuouslyCallback,
   ): Promise<IScannerControls> {
 
+    BrowserCodeReader.checkCallbackFnOrThrow(callbackFn);
+
     const timeout = this.options.tryPlayVideoTimeout;
 
     const video = await BrowserCodeReader.attachStreamToVideo(stream, preview, timeout);
@@ -743,6 +764,8 @@ export class BrowserCodeReader {
     callbackFn: DecodeContinuouslyCallback,
   ): Promise<IScannerControls> {
 
+    BrowserCodeReader.checkCallbackFnOrThrow(callbackFn);
+
     let videoConstraints: MediaTrackConstraints;
 
     if (!deviceId) {
@@ -764,6 +787,8 @@ export class BrowserCodeReader {
     callbackFn: DecodeContinuouslyCallback,
   ): Promise<IScannerControls> {
 
+    BrowserCodeReader.checkCallbackFnOrThrow(callbackFn);
+
     if (!source) {
       throw new ArgumentException('A video element must be provided.');
     }
@@ -788,6 +813,8 @@ export class BrowserCodeReader {
     callbackFn: DecodeContinuouslyCallback,
   ): Promise<IScannerControls> {
 
+    BrowserCodeReader.checkCallbackFnOrThrow(callbackFn);
+
     if (!url) {
       throw new ArgumentException('An URL must be provided.');
     }
@@ -984,6 +1011,8 @@ export class BrowserCodeReader {
     finalizeCallback?: (error?: Error) => void,
   ): IScannerControls {
 
+    BrowserCodeReader.checkCallbackFnOrThrow(callbackFn);
+
     /**
      * The HTML canvas element, used to draw the video or image's frame for decoding.
      */