[DevTools] Updated source map extension format + more precise types

packages/react-devtools-extensions/src/SourceMapTypes.js

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ */
+
+import type {EncodedHookMap} from './generateHookMap';
+
+export type ReactSourceMetadata = [?EncodedHookMap];
+export type ReactSourcesArray = $ReadOnlyArray<?ReactSourceMetadata>;
+
+export type FBSourceMetadata = [?{...}, ?ReactSourceMetadata];
+export type FBSourcesArray = $ReadOnlyArray<?FBSourceMetadata>;
+
+export type BasicSourceMap = {|
+  +file?: string,
+  +mappings: string,
+  +names: Array<string>,
+  +sourceRoot?: string,
+  +sources: Array<string>,
+  +sourcesContent?: Array<?string>,
+  +version: number,
+  +x_facebook_sources?: FBSourcesArray,
+  +x_react_sources?: ReactSourcesArray,
+|};
+
+export type IndexMapSection = {
+  map: IndexMap | BasicSourceMap,
+  offset: {
+    line: number,
+    column: number,
+    ...
+  },
+  ...
+};
+
+export type IndexMap = {|
+  +file?: string,
+  +mappings?: void, // avoids SourceMap being a disjoint union
+  +sourcesContent?: void,
+  +sections: Array<IndexMapSection>,
+  +version: number,
+  +x_facebook_sources?: FBSourcesArray,
+  +x_react_sources?: ReactSourcesArray,
+|};
+
+export type MixedSourceMap = IndexMap | BasicSourceMap;