Match lerped values using moreOrLessEquals (#64908)

Several of our tests make use of numbers without an exact floating point
representation (frequently 0.x where x!=5) which, when scaled, also
scale the error. The end result is that some of these tests currently
implicitly rely on an implementation detail of floating point math and
are sensitive to differences in the ~15th decimal place.

This patch reduces the sensitivity of some of these tests, checking
values using `moreOrLessEquals` from the flutter_test package
rather than requiring en exact match.

packages/flutter/test/cupertino/nav_bar_transition_test.dart

@@ -934,7 +934,7 @@ void main() {
     expect(bottomLargeTitle.text.style.color, const Color(0xff00050a));
     expect(bottomLargeTitle.text.style.fontWeight, FontWeight.w700);
     expect(bottomLargeTitle.text.style.fontFamily, '.SF Pro Display');
-    expect(bottomLargeTitle.text.style.letterSpacing, 0.374765625);
+    expect(bottomLargeTitle.text.style.letterSpacing, moreOrLessEquals(0.374765625));
 
     // The top back label is styled exactly the same way.
     final RenderParagraph topBackLabel =
@@ -942,19 +942,19 @@ void main() {
     expect(topBackLabel.text.style.color, const Color(0xff00050a));
     expect(topBackLabel.text.style.fontWeight, FontWeight.w700);
     expect(topBackLabel.text.style.fontFamily, '.SF Pro Display');
-    expect(topBackLabel.text.style.letterSpacing, 0.374765625);
+    expect(topBackLabel.text.style.letterSpacing, moreOrLessEquals(0.374765625));
 
     // Move animation further a bit.
     await tester.pump(const Duration(milliseconds: 200));
     expect(bottomLargeTitle.text.style.color, const Color(0xff006de4));
     expect(bottomLargeTitle.text.style.fontWeight, FontWeight.w400);
     expect(bottomLargeTitle.text.style.fontFamily, '.SF Pro Text');
-    expect(bottomLargeTitle.text.style.letterSpacing, -0.32379547566175454);
+    expect(bottomLargeTitle.text.style.letterSpacing, moreOrLessEquals(-0.32379547566175454));
 
     expect(topBackLabel.text.style.color, const Color(0xff006de4));
     expect(topBackLabel.text.style.fontWeight, FontWeight.w400);
     expect(topBackLabel.text.style.fontFamily, '.SF Pro Text');
-    expect(topBackLabel.text.style.letterSpacing, -0.32379547566175454);
+    expect(topBackLabel.text.style.letterSpacing, moreOrLessEquals(-0.32379547566175454));
   });
 
   testWidgets('Top middle fades in and slides in from the right', (WidgetTester tester) async {

packages/flutter/test/painting/colors_test.dart

@@ -26,11 +26,11 @@ void main() {
     expect(color.toColor(), const Color(0xb399816b));
 
     final HSVColor result = HSVColor.lerp(color, const HSVColor.fromAHSV(0.3, 128.0, 0.7, 0.2), 0.25);
-    expect(result.alpha, 0.6);
-    expect(result.hue, 53.0);
+    expect(result.alpha, moreOrLessEquals(0.6));
+    expect(result.hue, moreOrLessEquals(53.0));
     expect(result.saturation, greaterThan(0.3999));
     expect(result.saturation, lessThan(0.4001));
-    expect(result.value, 0.5);
+    expect(result.value, moreOrLessEquals(0.5));
   });
 
   test('HSVColor hue sweep test', () {
@@ -222,11 +222,11 @@ void main() {
     expect(color.toColor(), const Color(0xb3b8977a));
 
     final HSLColor result = HSLColor.lerp(color, const HSLColor.fromAHSL(0.3, 128.0, 0.7, 0.2), 0.25);
-    expect(result.alpha, 0.6);
-    expect(result.hue, 53.0);
+    expect(result.alpha, moreOrLessEquals(0.6));
+    expect(result.hue, moreOrLessEquals(53.0));
     expect(result.saturation, greaterThan(0.3999));
     expect(result.saturation, lessThan(0.4001));
-    expect(result.lightness, 0.5);
+    expect(result.lightness, moreOrLessEquals(0.5));
   });
 
   test('HSLColor hue sweep test', () {

packages/flutter/test/rendering/box_constraints_test.dart

@@ -71,25 +71,25 @@ void main() {
       maxHeight: 17.0,
     );
     BoxConstraints copy = BoxConstraints.lerp(null, constraints, 0.5);
-    expect(copy.minWidth, 1.5);
-    expect(copy.maxWidth, 3.5);
-    expect(copy.minHeight, 5.5);
-    expect(copy.maxHeight, 8.5);
+    expect(copy.minWidth, moreOrLessEquals(1.5));
+    expect(copy.maxWidth, moreOrLessEquals(3.5));
+    expect(copy.minHeight, moreOrLessEquals(5.5));
+    expect(copy.maxHeight, moreOrLessEquals(8.5));
     copy = BoxConstraints.lerp(constraints, null, 0.5);
-    expect(copy.minWidth, 1.5);
-    expect(copy.maxWidth, 3.5);
-    expect(copy.minHeight, 5.5);
-    expect(copy.maxHeight, 8.5);
+    expect(copy.minWidth, moreOrLessEquals(1.5));
+    expect(copy.maxWidth, moreOrLessEquals(3.5));
+    expect(copy.minHeight, moreOrLessEquals(5.5));
+    expect(copy.maxHeight, moreOrLessEquals(8.5));
     copy = BoxConstraints.lerp(const BoxConstraints(
       minWidth: 13.0,
       maxWidth: 17.0,
       minHeight: 111.0,
       maxHeight: 117.0,
     ), constraints, 0.2);
-    expect(copy.minWidth, 11.0);
-    expect(copy.maxWidth, 15.0);
-    expect(copy.minHeight, 91.0);
-    expect(copy.maxHeight, 97.0);
+    expect(copy.minWidth, moreOrLessEquals(11.0));
+    expect(copy.maxWidth, moreOrLessEquals(15.0));
+    expect(copy.minHeight, moreOrLessEquals(91.0));
+    expect(copy.maxHeight, moreOrLessEquals(97.0));
   });
 
   test('BoxConstraints lerp with unbounded width', () {