Support #EXT-X-GAP at stringify() (#157)

README.md

@@ -210,6 +210,7 @@ This section describes the structure of the object returned by `parse()` method.
 | `dateRange`  | `DateRange`   | No       | undefined | See [EXT-X-DATERANGE](https://tools.ietf.org/html/draft-pantos-http-live-streaming-23#section-4.3.2.7) |
 | `markers`  | [`SpliceInfo`]   | No       | [] | SCTE-35 messages associated with this segment|
 | `parts`  | [`PartialSegment`]   | No       | [] | Partial Segments that constitute this segment |
+| `gap` | boolean | No | undefined | See [EXT-X-GAP](https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis#section-4.4.4.7) |
 
 ### `PartialSegment` (extends `Data`)
 | Property          | Type     | Required | Default   | Description   |

stringify.ts

@@ -331,6 +331,9 @@ function buildSegment(lines: LineArray, segment: Segment, lastKey: string, lastM
   if (segment.discontinuity) {
     lines.push(`#EXT-X-DISCONTINUITY`);
   }
+  if (segment.gap) {
+    lines.push(`#EXT-X-GAP`);
+  }
   if (segment.key) {
     const line = buildKey(segment.key);
     if (line !== lastKey) {

test/spec/4_Playlists/4.3_Playlist-Tags/4.3.2_Media-Segment-Tags/4.4.4.7_EXT-X-GAP.spec.js

@@ -1,5 +1,7 @@
 const test = require("ava");
+const HLS = require('../../../../..');
 const utils = require("../../../../helpers/utils");
+const {equalPlaylist} = require("../../../../helpers/matchers");
 
 // https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis#section-4.4.4.7
 
@@ -38,3 +40,17 @@ test('#EXT-X-TAG_02', t => {
     #EXT-X-ENDLIST
   `);
 });
+
+test('#EXT-X-TAG_03', t => {
+  const txt = `
+    #EXTM3U
+    #EXT-X-VERSION:8
+    #EXT-X-TARGETDURATION:5
+    #EXT-X-GAP
+    #EXTINF:4,
+    1.ts
+  `;
+  const playlist = HLS.parse(txt);
+  t.truthy(playlist.segments[0].gap);
+  equalPlaylist(t, txt, HLS.stringify(playlist));
+});