Assert close enough refactoring (#370)

* Introduce helper function fail

* Simplify signatures for assertContentCloseEnough

* In the middle of refactoring

* Don't use nested assertions in assertCloseEnough family of functions

* Platform-aware default epsilon

* Correct one of assertion error messages

* Yet another typo in a commit message

skiko/src/commonTest/kotlin/org/jetbrains/skia/PathMeasureTest.kt

@@ -31,7 +31,7 @@ class PathMeasureTest {
     fun getPosition() = runTest {
         Path().moveTo(0f, 10f).lineTo(20f, 0f).moveTo(0f, 40f).lineTo(30f, 50f).use { path ->
             PathMeasure(path, false).use { measure ->
-                assertCloseEnough(Point(0.89442724f, 9.552787f), measure.getPosition(1f))
+                assertCloseEnough(Point(0.89442724f, 9.552787f), measure.getPosition(1f)!!)
             }
         }
     }
@@ -44,52 +44,52 @@ class PathMeasureTest {
             PathMeasure(path, false).use { measure ->
                 Path().lineTo(10f, 10f).use { path2 ->
                     assertEquals(40f, measure.length)
-                    assertCloseEnough(Point(0f, 0f), measure.getPosition(0f))
-                    assertCloseEnough(Point(1f, 0f), measure.getTangent(0f))
-                    assertCloseEnough(Point(20f, 0f), measure.getPosition(20f))
-                    assertCloseEnough(Point(1f, 0f), measure.getTangent(20f))
+                    assertCloseEnough(Point(0f, 0f), measure.getPosition(0f)!!)
+                    assertCloseEnough(Point(1f, 0f), measure.getTangent(0f)!!)
+                    assertCloseEnough(Point(20f, 0f), measure.getPosition(20f)!!)
+                    assertCloseEnough(Point(1f, 0f), measure.getTangent(20f)!!)
                     assertEquals(false, measure.isClosed)
                     assertCloseEnough(
                         Matrix33.makeTranslate(20f, 0f), measure.getMatrix(
                             20f,
                             getPosition = true,
                             getTangent = false
-                        )
+                        )!!
                     )
                     assertCloseEnough(
                         Matrix33.makeRotate(0f), measure.getMatrix(
                             20f,
                             getPosition = false,
                             getTangent = true
-                        )
+                        )!!
                     )
                     assertCloseEnough(
                         Matrix33.makeTranslate(20f, 0f).makeConcat(Matrix33.makeRotate(0f)),
-                        measure.getMatrix(20f, getPosition = true, getTangent = true)
+                        measure.getMatrix(20f, getPosition = true, getTangent = true)!!
                     )
                     measure.nextContour()
                     assertCloseEnough(14.14213f, measure.length)
-                    assertCloseEnough(Point(0f, 40f), measure.getPosition(0f))
-                    assertCloseEnough(Point(0.70710677f, 0.70710677f), measure.getTangent(0f))
-                    assertCloseEnough(Point(4.949747f, 44.949745f), measure.getPosition(7f))
-                    assertCloseEnough(Point(0.70710677f, 0.70710677f), measure.getTangent(7f))
+                    assertCloseEnough(Point(0f, 40f), measure.getPosition(0f)!!)
+                    assertCloseEnough(Point(0.70710677f, 0.70710677f), measure.getTangent(0f)!!)
+                    assertCloseEnough(Point(4.949747f, 44.949745f), measure.getPosition(7f)!!)
+                    assertCloseEnough(Point(0.70710677f, 0.70710677f), measure.getTangent(7f)!!)
                     assertCloseEnough(
                         Matrix33.makeTranslate(4.949747f, 44.949745f), measure.getMatrix(
                             7f,
                             getPosition = true,
                             getTangent = false
-                        )
+                        )!!
                     )
                     assertCloseEnough(
                         Matrix33.makeRotate(45f), measure.getMatrix(
                             7f,
                             getPosition = false,
                             getTangent = true
-                        )
+                        )!!
                     )
                     assertCloseEnough(
                         Matrix33.makeTranslate(4.949747f, 44.949745f).makeConcat(Matrix33.makeRotate(45f)),
-                        measure.getMatrix(7f, getPosition = true, getTangent = true)
+                        measure.getMatrix(7f, getPosition = true, getTangent = true)!!
                     )
                     measure.setPath(path2, false)
                     assertCloseEnough(14.142136f, measure.length)

skiko/src/commonTest/kotlin/org/jetbrains/skia/SvgTest.kt

@@ -37,7 +37,7 @@ class SvgTest {
         require(e.viewBox == null)
         require(e.tag == SVGTag.SVG)
         e.viewBox = Rect(0f, 1f, 100f, 200f)
-        assertCloseEnough(Rect(0f, 1f, 100f, 200f), e.viewBox)
+        assertCloseEnough(Rect(0f, 1f, 100f, 200f), e.viewBox!!)
         val aspectRatio = SVGPreserveAspectRatio(SVGPreserveAspectRatioAlign.XMIN_YMIN, SVGPreserveAspectRatioScale.MEET)
         e.preserveAspectRatio = aspectRatio
         assertEquals(aspectRatio, e.preserveAspectRatio)

skiko/src/commonTest/kotlin/org/jetbrains/skia/TextBlobTest.kt

@@ -66,7 +66,7 @@ class TextBlobTest {
                 102.99094f, 132.33693f, 134.25397f, 141.45454f, 158.58522f, 173.29857f, 179.27502f, 212.21196f,
                 217.8335f, 229.33693f, 231.25397f
             ),
-            actual = textBlob.getIntercepts(lowerBound = 0f, upperBound = 1f),
+            actual = textBlob.getIntercepts(lowerBound = 0f, upperBound = 1f)!!,
             epsilon = eps
         )
 

skiko/src/commonTest/kotlin/org/jetbrains/skia/util/assertCloseEnough.kt

@@ -4,58 +4,79 @@ import org.jetbrains.skia.Color4f
 import org.jetbrains.skia.Matrix33
 import org.jetbrains.skia.Point
 import org.jetbrains.skia.Rect
+import org.jetbrains.skiko.KotlinBackend
+import org.jetbrains.skiko.kotlinBackend
 import kotlin.math.abs
-import kotlin.test.assertNotNull
 import kotlin.test.assertTrue
 
-private const val EPSILON = 0.00001f
+private val EPSILON = if (kotlinBackend == KotlinBackend.JS) 0.00001f else 0.00000001f
+
+private inline fun Float.isCloseEnoughTo(b: Float, epsilon: Float) = abs(this - b) < epsilon
+private inline fun Point.isCloseEnoughTo(b: Point, epsilon: Float) =
+    x.isCloseEnoughTo(b.x, epsilon) && y.isCloseEnoughTo(b.y, epsilon)
+
+private inline fun Color4f.isCloseEnoughTo(otherColor: Color4f, epsilon: Float) =
+    r.isCloseEnoughTo(otherColor.r, epsilon) && g.isCloseEnoughTo(
+        otherColor.g,
+        epsilon
+    ) && b.isCloseEnoughTo(otherColor.b, epsilon) && a.isCloseEnoughTo(otherColor.a, epsilon)
+
+private inline fun Rect.isCloseEnoughTo(rect: Rect, epsilon: Float): Boolean =
+    left.isCloseEnoughTo(rect.left, epsilon) && right.isCloseEnoughTo(rect.right, epsilon)
+            && top.isCloseEnoughTo(rect.top, epsilon) && bottom.isCloseEnoughTo(rect.bottom, epsilon)
 
 internal fun assertCloseEnough(expected: Float, actual: Float, epsilon: Float = EPSILON) {
-    assertTrue(abs(expected - actual) < epsilon, message = "expected=$expected, actual=$actual, eps=$epsilon")
+    assertTrue(expected.isCloseEnoughTo(actual, epsilon), message = "expected=$expected, actual=$actual, eps=$epsilon")
 }
 
-internal fun assertCloseEnough(expected: Point, actual: Point?, epsilon: Float = EPSILON) {
-    assertCloseEnough(expected.x, actual!!.x, epsilon)
-    assertCloseEnough(expected.y, actual.y, epsilon)
+internal fun assertCloseEnough(expected: Point, actual: Point, epsilon: Float = EPSILON) {
+    assertTrue(expected.isCloseEnoughTo(actual, epsilon), message = "expected=$expected, actual=$actual, eps=$epsilon")
 }
 
-internal fun assertCloseEnough(expected: Matrix33, actual: Matrix33?, epsilon: Float = EPSILON) {
-    expected.mat.zip(actual!!.mat).forEach { (a, b) -> assertCloseEnough(a, b, epsilon) }
+internal fun assertCloseEnough(expected: Matrix33, actual: Matrix33, epsilon: Float = EPSILON) {
+    assertTrue(
+        expected.mat.zip(actual.mat).all { (a, b) -> a.isCloseEnoughTo(b, epsilon) },
+        message = "expected=$expected, actual=$actual, eps=$epsilon"
+    )
 }
 
-internal fun assertCloseEnough(expected: Color4f, actual: Color4f?, epsilon: Float = EPSILON) {
-    assertCloseEnough(expected.r, actual!!.r, epsilon)
-    assertCloseEnough(expected.g, actual.g, epsilon)
-    assertCloseEnough(expected.b, actual.b, epsilon)
-    assertCloseEnough(expected.a, actual.a, epsilon)
+internal fun assertCloseEnough(expected: Color4f, actual: Color4f, epsilon: Float = EPSILON) {
+    assertTrue(expected.isCloseEnoughTo(actual, epsilon), message = "expected=$expected, actual=$actual, eps=$epsilon")
 }
 
-internal fun assertCloseEnough(expected: Rect, actual: Rect?, epsilon: Float = EPSILON) {
-    assertCloseEnough(expected.left, actual!!.left, epsilon)
-    assertCloseEnough(expected.top, actual.top, epsilon)
-    assertCloseEnough(expected.right, actual.right, epsilon)
-    assertCloseEnough(expected.bottom, actual.bottom, epsilon)
+internal fun assertCloseEnough(expected: Rect, actual: Rect, epsilon: Float = EPSILON) {
+    assertTrue(expected.isCloseEnoughTo(actual, epsilon), message = "expected=$expected, actual=$actual, eps=$epsilon")
 }
 
-internal fun assertContentCloseEnough(expected: FloatArray, actual: FloatArray?, epsilon: Float = EPSILON) {
-    if (actual == null) {
-        throw AssertionError("expected $expected, got null")
-    }
+private fun fail(message: String) {
+    throw AssertionError(message)
+}
+
+internal fun <T> assertContentEquivalent(expected: Iterator<T>, actual: Iterator<T>, eq: (a: T, b: T) -> Boolean) {
+    var count = 0
 
-    for (i in expected.indices) {
-        if (abs(expected[i] - actual[i]) > epsilon) {
-            throw AssertionError("results differ at index$i, expected ${expected[i]}, got ${actual[i]}")
+    while (expected.hasNext() && actual.hasNext()) {
+        val a = expected.next()
+        val b = actual.next()
+        if (!eq(a, b)) {
+            fail("results differ at index $count, expected $a, got $b")
         }
+        count++
     }
-}
 
-internal fun assertContentCloseEnough(expected: Array<Point>, actual: Array<Point>?, epsilon: Float = EPSILON) {
-    assertNotNull(actual)
-    for (i in expected.indices) {
-        try {
-            assertCloseEnough(expected[i], actual[i], epsilon)
-        } catch (e: AssertionError) {
-            throw AssertionError("results differ at index $i, ${e.message}")
-        }
+    if (expected.hasNext()) {
+        fail("expected $expected has more items than actual $actual (which has $count)")
+    }
+
+    if (actual.hasNext()) {
+        fail("actual $actual has more items than actual $expected (which has $count)")
     }
 }
+
+internal fun assertContentCloseEnough(expected: FloatArray, actual: FloatArray, epsilon: Float = EPSILON) {
+    assertContentEquivalent(expected.iterator(), actual.iterator()) { a, b -> a.isCloseEnoughTo(b, epsilon) }
+}
+
+internal fun assertContentCloseEnough(expected: Array<Point>, actual: Array<Point>, epsilon: Float = EPSILON) {
+    assertContentEquivalent(expected.iterator(), actual.iterator()) { a, b -> a.isCloseEnoughTo(b, epsilon) }
+}