Add support for videoEdit.preview() (#298)

Author: patrick-tolosa

__TESTS__/unit/actions/VideoEdit.test.ts

@@ -116,4 +116,16 @@ describe('Tests for Transformation Action -- VideoEdit', () => {
 
     expect(url).toBe('https://res.cloudinary.com/demo/video/upload/e_volume:10/sample');
   });
+
+  it('Tests a preview transformation for a video', () => {
+    const url = createNewVideo('sample')
+      .videoEdit(
+        VideoEdit.preview()
+          .duration(5)
+          .minimumSegmentDuration(1)
+          .maximumSegments(10)
+      ).toString();
+
+    expect(url).toContain('e_preview:duration_5.0:min_seg_dur_1.0:max_seg_10');
+  });
 });

src/actions/videoEdit.ts

@@ -2,6 +2,7 @@ import TrimAction from './videoEdit/TrimAction';
 import ConcatenateAction from './videoEdit/ConcatenateAction';
 import VolumeAction from "./videoEdit/VolumeAction";
 import {VideoSource} from "../values/source/sourceTypes/VideoSource";
+import {PreviewAction} from "./videoEdit/PreviewAction";
 
 /**
  * Methods for editing a video.
@@ -53,7 +54,20 @@ function volume(volumeValue: string | number): VolumeAction{
   return new VolumeAction(volumeValue);
 }
 
-export declare type videoEditType = VolumeAction | TrimAction | ConcatenateAction;
+/**
+ * @description A video preview is a short excerpt from a video that can be used to engage your audience and help them select the video content that interests them.
+ *
+ * <b>Learn more</b>: {@link https://cloudinary.com/documentation/video_manipulation_and_delivery#generate_an_ai_based_video_preview |
+  * Create a video preview}
+ *
+ * @memberOf Actions.VideoEdit
+ * @return {Actions.VideoEdit.PreviewAction}
+ */
+function preview(): PreviewAction{
+  return new PreviewAction();
+}
+
+export declare type videoEditType = VolumeAction | TrimAction | ConcatenateAction | PreviewAction;
 
-const VideoEdit = {concatenate, trim, volume};
-export {VideoEdit, concatenate, trim, volume};
+const VideoEdit = {concatenate, trim, volume, preview};
+export {VideoEdit, concatenate, trim, volume, preview};

src/actions/videoEdit/PreviewAction.ts

@@ -0,0 +1,58 @@
+import {Action} from "../../internal/Action";
+import {toFloatAsString} from "../../internal/utils/toFloatAsString";
+
+/**
+ * @description Class for creating a preview of a video
+ * @memberOf Actions.VideoEdit
+ * @extend {SDK.Action}
+ */
+class PreviewAction extends Action {
+  private _minSeg: string | number;
+  private _maxSeg: string | number;
+  private _duration: string | number;
+
+  constructor() {
+    super();
+  }
+
+  /**
+   * @description Control the duration of the video segments
+   * @param {string|number} minSegDuration The duration of a video segment
+   * @return {this}
+   */
+  minimumSegmentDuration(minSegDuration: string | number): this {
+    this._minSeg = minSegDuration;
+    return this;
+  }
+
+  /**
+   * @description Control the number of the video segments
+   * @param {string|number} maxSeg The number of the video segments.
+   * @return {this}
+   */
+  maximumSegments(maxSeg: string | number): this {
+    this._maxSeg = maxSeg;
+    return this;
+  }
+
+  /**
+   * @description control the length of the generated preview
+   * @param {string|number} duration The duration in seconds such as 1.2, or 5.0
+   * @return {this}
+   */
+  duration(duration: string | number): this {
+    this._duration = duration;
+    return this;
+  }
+
+  toString(): string {
+    return [
+      'e_preview',
+      this._duration && `duration_${toFloatAsString(this._duration)}`,
+      this._minSeg && `min_seg_dur_${toFloatAsString(this._minSeg)}`,
+      this._maxSeg && `max_seg_${toFloatAsString(this._maxSeg)}`
+    ].filter((a) => a).join(':');
+  }
+}
+
+export {PreviewAction};