docs(examples): add counter example (#234)

Author: felangel

.github/workflows/examples_counter.yaml

@@ -0,0 +1,23 @@
+name: examples/counter
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+on:
+  pull_request:
+    paths:
+      - "examples/counter/routes/**"
+      - "examples/counter/lib/**"
+      - "examples/counter/test/**"
+      - ".github/workflows/examples_counter.yaml"
+    branches:
+      - main
+
+jobs:
+  build:
+    uses: VeryGoodOpenSource/very_good_workflows/.github/workflows/dart_package.yml@v1
+    with:
+      working_directory: examples/counter
+      analyze_directories: "routes test"
+      report_on: "routes"

examples/counter/.gitignore

@@ -0,0 +1,13 @@
+# See https://www.dartlang.org/guides/libraries/private-files
+
+# Files and directories created by pub
+.dart_tool/
+.packages
+pubspec.lock
+
+# Files and directories created by dart_frog
+build/
+.dart_frog
+
+# Test related files
+coverage/

examples/counter/README.md

@@ -0,0 +1,11 @@
+# counter
+
+[![style: very good analysis][very_good_analysis_badge]][very_good_analysis_link]
+[![License: MIT][license_badge]][license_link]
+
+An example counter app built with `dart_frog`.
+
+[license_badge]: https://img.shields.io/badge/license-MIT-blue.svg
+[license_link]: https://opensource.org/licenses/MIT
+[very_good_analysis_badge]: https://img.shields.io/badge/style-very_good_analysis-B22C89.svg
+[very_good_analysis_link]: https://pub.dev/packages/very_good_analysis

examples/counter/analysis_options.yaml

@@ -0,0 +1,7 @@
+include: package:very_good_analysis/analysis_options.3.0.1.yaml
+analyzer:
+  exclude:
+    - build/**
+linter:
+  rules:
+    file_names: false

examples/counter/pubspec.yaml

@@ -0,0 +1,15 @@
+name: counter
+description: An example counter app built with Dart Frog.
+version: 1.0.0+1
+publish_to: none
+
+environment:
+  sdk: ">=2.17.0 <3.0.0"
+
+dependencies:
+  dart_frog: ^0.0.1-dev
+
+dev_dependencies:
+  mocktail: ^0.3.0
+  test: ^1.19.2
+  very_good_analysis: ^3.0.1

examples/counter/routes/_middleware.dart

@@ -0,0 +1,7 @@
+import 'package:dart_frog/dart_frog.dart';
+
+int _count = 0;
+
+Handler middleware(Handler handler) {
+  return handler.use(provider<int>((_) => ++_count));
+}

examples/counter/routes/index.dart

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+import 'package:dart_frog/dart_frog.dart';
+
+Response onRequest(RequestContext context) {
+  final count = context.read<int>();
+  return Response(
+    body: 'You have requested this route $count time(s).',
+  );
+}

examples/counter/test/routes/_middleware_test.dart

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+import 'package:dart_frog/dart_frog.dart';
+import 'package:mocktail/mocktail.dart';
+import 'package:test/test.dart';
+
+import '../../routes/_middleware.dart';
+
+class _MockRequestContext extends Mock implements RequestContext {}
+
+void main() {
+  group('middleware', () {
+    test('provides incremented count', () async {
+      int? count;
+      final handler = middleware(
+        (context) {
+          count = context.read<int>();
+          return Response(body: '');
+        },
+      );
+      final request = Request.get(Uri.parse('http://localhost/'));
+      final context = _MockRequestContext();
+      when(() => context.request).thenReturn(request);
+
+      await handler(context);
+      expect(count, equals(1));
+
+      await handler(context);
+      expect(count, equals(2));
+
+      await handler(context);
+      expect(count, equals(3));
+    });
+  });
+}

examples/counter/test/routes/index_test.dart

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+import 'dart:io';
+
+import 'package:dart_frog/dart_frog.dart';
+import 'package:mocktail/mocktail.dart';
+import 'package:test/test.dart';
+
+import '../../routes/index.dart' as route;
+
+class _MockRequestContext extends Mock implements RequestContext {}
+
+void main() {
+  group('GET /', () {
+    test('responds with a 200 and count.', () async {
+      const count = 42;
+      final context = _MockRequestContext();
+      when(() => context.read<int>()).thenReturn(count);
+      final response = route.onRequest(context);
+      expect(response.statusCode, equals(HttpStatus.ok));
+      expect(
+        response.body(),
+        completion(
+          equals('You have requested this route $count time(s).'),
+        ),
+      );
+    });
+  });
+}