Better recursive paging (#54)

Author: Rexios80

README.md

@@ -27,6 +27,7 @@ Aims to be the most complete and stable pub.dev API client. If any particular en
   - [Flutter Favorites](#flutter-favorites)
   - [Google Packages](#google-packages)
   - [Publisher Packages](#publisher-packages)
+  - [All Packages](#all-packages)
 
 ## Usage
 
@@ -231,7 +232,6 @@ print(results.packages)
 Returns all Flutter favorites on pub.dev
 
 ```dart
-
 final results = await client.fetchFlutterFavorites();
 ```
 
@@ -240,7 +240,6 @@ final results = await client.fetchFlutterFavorites();
 Returns all official Google packages. This will be a large payload with hundreds of packages.
 
 ```dart
-
 final results = await client.fetchGooglePackages();
 ```
 
@@ -252,3 +251,11 @@ Returns all packages for a specific publisher
 
 final results = await client.fetchPublisherPackages();
 ```
+
+### All Packages
+
+Returns all packages that match a given query
+
+```dart
+final results = await fetchAllPackages('', tags: [PackageTag.publisher('leoafarias.com')])
+```

lib/src/helpers/recursive_paging.dart

@@ -1,17 +1,14 @@
 import '../models/search_results_model.dart';
-import '../pub_api_client_base.dart';
 
-Future<List<PackageResult>> recursivePaging(
-  PubClient client,
-  SearchResults prevResults,
+Future<List<T>> recursivePaging<T>(
+  PaginatedResults<T> prevResults,
+  Future<PaginatedResults<T>> Function(String url) getNext,
 ) async {
-  final packages = [...prevResults.packages];
+  final results = prevResults.results;
   final nextPage = prevResults.next;
-  if (nextPage != null) {
-    final results = await client.nextPage(nextPage);
-    final nextResults = await recursivePaging(client, results);
-    packages.addAll(nextResults);
+  if (nextPage == null) {
+    return results;
   }
-
-  return packages;
+  final next = await getNext(nextPage);
+  return results + await recursivePaging(next, getNext);
 }

lib/src/models/search_results_model.dart

@@ -2,11 +2,29 @@ import 'package:dart_mappable/dart_mappable.dart';
 
 part 'search_results_model.mapper.dart';
 
+/// Base class for results that are paginated
+abstract class PaginatedResults<T> {
+  /// The current results
+  List<T> get results;
+
+  /// The URL to the next page of results
+  String? get next;
+
+  const PaginatedResults();
+}
+
 /// Search Results Model
 @MappableClass()
-class SearchResults with SearchResultsMappable {
+class SearchResults extends PaginatedResults<PackageResult>
+    with SearchResultsMappable {
   final List<PackageResult> packages;
+
+  @override
+  List<PackageResult> get results => packages;
+
+  @override
   final String? next;
+
   const SearchResults({
     required this.packages,
     this.next,

lib/src/pub_api_client_base.dart

@@ -212,6 +212,15 @@ class PubClient {
         .toList();
   }
 
+  /// Get all packages that match the query
+  Future<List<PackageResult>> fetchAllPackages(
+    String query, {
+    List<String> tags = const [],
+  }) async {
+    final results = await search(query, tags: tags);
+    return recursivePaging(results, nextPage);
+  }
+
   /// Retrieves all Google packages from pub.dev
   /// Mostly used as an internal tool to generate
   /// google_packages_list.dart
@@ -240,22 +249,19 @@ class PubClient {
 
   /// Retrieves all the flutter favorites
   Future<List<String>> fetchFlutterFavorites() async {
-    final searchResults =
-        await search('', tags: [PackageTag.isFlutterFavorite]);
-    final results = await recursivePaging(this, searchResults);
+    final results =
+        await fetchAllPackages('', tags: [PackageTag.isFlutterFavorite]);
     return results.map((r) => r.package).toList();
   }
 
   Future<List<PackageResult>> fetchPublisherPackages(
     String publisherName, {
     List<String> tags = const [],
-  }) async {
-    final results = await search('', tags: [
-      PackageTag.publisher(publisherName),
-      ...tags,
-    ]);
-    return recursivePaging(this, results);
-  }
+  }) =>
+      fetchAllPackages('', tags: [
+        PackageTag.publisher(publisherName),
+        ...tags,
+      ]);
 
   void close() {
     _client.close();