docs: expand some api descriptions

src/native.ts

@@ -33,6 +33,9 @@ type FileAccessType = {
       path?: string;
     }
   ): Promise<FetchResult>;
+  /**
+   * Only defined on iOS.
+   */
   getAppGroupDir(groupName: string): Promise<string>;
   hash(path: string, algorithm: HashAlgorithm): Promise<string>;
   isDir(path: string): Promise<boolean>;
@@ -45,4 +48,10 @@ type FileAccessType = {
   writeFile(path: string, data: string, encoding: Encoding): Promise<void>;
 };
 
+/**
+ * Native module API.
+ *
+ * Most functions are the same as the JS wrapper. However native calls do
+ * not support default parameters.
+ */
 export const FileAccessNative: FileAccessType = NativeModules.RNFileAccess;

src/types.ts

@@ -9,29 +9,64 @@ export type Encoding = 'utf8' | 'base64';
 export type ExternalDir = 'audio' | 'downloads' | 'images' | 'video';
 
 export type FetchResult = {
+  /**
+   * Response HTTP headers.
+   */
   headers: { [key: string]: string };
+
+  /**
+   * True if the response is a 2XX HTTP status.
+   */
   ok: boolean;
+
+  /**
+   * Note: this value may not be accurate.
+   */
   redirected: boolean;
+
+  /**
+   * HTTP response status code.
+   */
   status: number;
+
+  /**
+   * Associated text for HTTP status code.
+   */
   statusText: string;
+
+  /**
+   * Final URL provided by the HTTP response.
+   */
   url: string;
 };
 
 export type FileStat = {
+  /**
+   * Filename does not include the path.
+   */
   filename: string;
   lastModified: number;
   path: string;
+  /**
+   * File size in bytes.
+   */
   size: number;
   type: 'directory' | 'file';
 };
 
+/**
+ * Values are in bytes.
+ */
 export type FsStat = {
   internal_free: number;
   internal_total: number;
   external_free?: number;
   external_total?: number;
 };
 
+/**
+ * MD5 and SHA-1 are insecure. Avoid when possible.
+ */
 export type HashAlgorithm =
   | 'MD5'
   | 'SHA-1'