[Adjustment] - Make takePhoto()'s Finder optional (Resolves #28) (#30)

Author: matthew-carroll

lib/src/goldens/golden_camera.dart

@@ -3,18 +3,22 @@ import 'dart:ui';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import 'package:flutter_test_goldens/src/goldens/golden_rendering.dart';
+
 /// A camera for taking golden screenshots and storing them for later reference.
 class GoldenCamera {
-  GoldenCamera(this._tester);
-
-  final WidgetTester _tester;
+  GoldenCamera();
 
   List<GoldenPhoto> get photos => List.from(_photos);
   final _photos = <GoldenPhoto>[];
 
   /// Takes a screenshot of the given [finder] and stores it in [photos]
   /// along with its [description].
-  Future<void> takePhoto(Finder finder, String description) async {
+  ///
+  /// {@macro golden_image_bounds_default_finder}
+  Future<void> takePhoto(String description, [Finder? finder]) async {
+    finder = finder ?? find.byType(GoldenImageBounds);
+
     expect(finder, findsOne);
 
     final renderObject = finder.evaluate().first.findRenderObject();

lib/src/scenes/film_strip.dart

@@ -62,12 +62,18 @@ class FilmStrip {
   }
 
   /// Take a golden photo screenshot of the current Flutter UI.
-  FilmStrip takePhoto(Finder photoBoundsFinder, String description) {
+  ///
+  /// {@template golden_image_bounds_default_finder}
+  /// If no [finder] is provided, then it's assumed that somewhere in the widget tree is
+  /// a [GoldenImageBounds] widget. That widget is used as the boundary for this photo.
+  /// If no such widget exists, an error is thrown.
+  /// {@endtemplate}
+  FilmStrip takePhoto(String description, [Finder? photoBoundsFinder]) {
     if (_setup == null) {
       throw Exception("Can't take a photo before setup. Please call setup() or setupWithPump()");
     }
 
-    _steps.add(_FilmStripPhotoRequest(photoBoundsFinder, description));
+    _steps.add(_FilmStripPhotoRequest(photoBoundsFinder ?? find.byType(GoldenImageBounds), description));
 
     return this;
   }
@@ -137,7 +143,7 @@ class FilmStrip {
     // anti-aliasing and other artifacts from fractional pixel offsets.
     _tester.view.devicePixelRatio = 1.0;
 
-    final camera = GoldenCamera(_tester);
+    final camera = GoldenCamera();
     final testContext = FilmStripTestContext();
 
     // Setup the scene.
@@ -163,7 +169,7 @@ class FilmStrip {
               "Failed to find a render object for photo '${step.description}', using finder '${step.photoBoundsFinder}'",
         );
 
-        await camera.takePhoto(step.photoBoundsFinder, step.description);
+        await camera.takePhoto(step.description, step.photoBoundsFinder);
 
         continue;
       }

lib/src/scenes/gallery.dart

@@ -143,7 +143,7 @@ class Gallery {
     FtgLog.pipeline.info("Rendering or comparing golden - $_sceneName");
 
     // Build each gallery item and screenshot it.
-    final camera = GoldenCamera(_tester);
+    final camera = GoldenCamera();
     for (final item in _items) {
       FtgLog.pipeline.info("Building gallery item: ${item.description}, item decorated: $_itemDecorator");
 
@@ -190,7 +190,7 @@ class Gallery {
         reason: "Failed to find a render object for gallery item '${item.description}'",
       );
 
-      await camera.takePhoto(item.boundsFinder, item.description);
+      await camera.takePhoto(item.description, item.boundsFinder);
     }
 
     // Lay out gallery items in the desired layout.

test_goldens/flutter/buttons/buttons_test.dart

@@ -21,11 +21,11 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         .hoverOver(find.byType(ElevatedButton))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         .renderOrCompareGolden(
           goldenName: "button_elevated_interactions",
           layout: SceneLayout.row,
@@ -45,11 +45,11 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         .hoverOver(find.byType(TextButton))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         .renderOrCompareGolden(
           goldenName: "button_text_interactions",
           layout: SceneLayout.row,
@@ -78,11 +78,11 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         .hoverOver(find.byType(IconButton))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         .renderOrCompareGolden(
           goldenName: "button_icon_interactions",
           layout: SceneLayout.row,
@@ -102,11 +102,11 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         .hoverOver(find.byType(FloatingActionButton))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         .renderOrCompareGolden(
           goldenName: "button_fab_interactions",
           layout: SceneLayout.row,
@@ -133,15 +133,15 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         // .takePhoto(find.byType(FlutterWidgetScaffold), "idle")
 
         .hoverOver(find.byType(FloatingActionButton))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         // .takePhoto(find.byType(FlutterWidgetScaffold), "idle")
 
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         // .takePhoto(find.byType(FlutterWidgetScaffold), "pressed")
         .renderOrCompareGolden(
           goldenName: "button_extended_fab_interactions",

test_goldens/flutter/buttons/failures/failure_button_extended_fab_gallery.png_Icon + Text.png

@@ -28,11 +28,11 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         .hoverOver(find.byType(ListTile))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         .renderOrCompareGolden(
           goldenName: "list_tile_interactions",
           layout: SceneLayout.column,

test_goldens/flutter/buttons/failures/failure_button_extended_fab_gallery.png_Icon.png

@@ -19,18 +19,18 @@ void main() {
             ),
           );
         })
-        .takePhoto(find.byKey(goldenKey), "idle")
+        .takePhoto("idle", find.byKey(goldenKey))
         .hoverOver(find.byType(TextField))
-        .takePhoto(find.byKey(goldenKey), "hover")
+        .takePhoto("hover", find.byKey(goldenKey))
         .pressHover()
-        .takePhoto(find.byKey(goldenKey), "pressed")
+        .takePhoto("pressed", find.byKey(goldenKey))
         .releaseHover()
-        .takePhoto(find.byKey(goldenKey), "placed caret")
+        .takePhoto("placed caret", find.byKey(goldenKey))
         .modifyScene((tester, testContext) async {
           await tester.enterText(find.byType(TextField), "Hello, world!");
           await tester.pumpAndSettle();
         })
-        .takePhoto(find.byKey(goldenKey), "typed text")
+        .takePhoto("typed text", find.byKey(goldenKey))
         .renderOrCompareGolden(
           goldenName: "textfield_interactions",
           layout: SceneLayout.column,