packager: buck library: expose asset content

Reviewed By: davidaurelio

Differential Revision: D4945778

fbshipit-source-id: ea132a3d284ed09c59c69afbdd7b707af9e521b9

packages/metro-bundler/src/Bundler/index.js

@@ -68,7 +68,7 @@ export type GetTransformOptions = (
   getDependenciesOf: string => Promise<Array<string>>,
 ) => Promise<ExtraTransformOptions>;
 
-type AssetDescriptor = {
+export type AssetDescriptor = {
   +__packager_asset: boolean,
   +httpServerLocation: string,
   +width: ?number,
@@ -79,7 +79,7 @@ type AssetDescriptor = {
   +type: string,
 };
 
-type ExtendedAssetDescriptor = AssetDescriptor & {
+export type ExtendedAssetDescriptor = AssetDescriptor & {
   +fileSystemLocation: string,
   +files: Array<string>,
 };

packages/metro-bundler/src/ModuleGraph/types.flow.js

@@ -140,3 +140,11 @@ export type LibraryOptions = {|
   platform?: string,
   root: string,
 |};
+
+export type Base64Content = string;
+
+export type Library = {|
+  files: Array<TransformedFile>,
+  /* cannot be a Map because it's JSONified later on */
+  assets: {[destFilePath: string]: Base64Content},
+|};