Move top-level functions to Signal.Util

ts/util/GoogleChrome.ts

@@ -0,0 +1,39 @@
+/**
+ * @prettier
+ */
+import * as MIME from '../types/MIME';
+
+interface MIMETypeSupportMap {
+  [key: string]: boolean;
+}
+
+// See: https://en.wikipedia.org/wiki/Comparison_of_web_browsers#Image_format_support
+const SUPPORTED_IMAGE_MIME_TYPES: MIMETypeSupportMap = {
+  'image/bmp': true,
+  'image/gif': true,
+  'image/jpeg': true,
+  'image/svg+xml': true,
+  'image/webp': true,
+  'image/x-xbitmap': true,
+  // ICO
+  'image/vnd.microsoft.icon': true,
+  'image/ico': true,
+  'image/icon': true,
+  'image/x-icon': true,
+  // PNG
+  'image/apng': true,
+  'image/png': true,
+};
+
+export const isImageTypeSupported = (mimeType: MIME.MIMEType): boolean =>
+  SUPPORTED_IMAGE_MIME_TYPES[mimeType] === true;
+
+const SUPPORTED_VIDEO_MIME_TYPES: MIMETypeSupportMap = {
+  'video/mp4': true,
+  'video/ogg': true,
+  'video/webm': true,
+};
+
+// See: https://www.chromium.org/audio-video
+export const isVideoTypeSupported = (mimeType: MIME.MIMEType): boolean =>
+  SUPPORTED_VIDEO_MIME_TYPES[mimeType] === true;