[Tests] BinaryInteger.random(in:using:).

oscbyspro · Jul 26, 2024 · fc44e91 · fc44e91
1 parent ab296e7
commit fc44e91
Showing 1 changed file with 68 additions and 1 deletion.
diff --git a/Tests/UltimathnumTests/BinaryInteger+Random.swift b/Tests/UltimathnumTests/BinaryInteger+Random.swift
@@ -20,7 +20,7 @@ import TestKit
 final class BinaryIntegerTestsOnRandom: XCTestCase {
 
     //=------------------------------------------------------------------------=
-    // MARK: Tests
+    // MARK: Tests x Range
     //=------------------------------------------------------------------------=
 
     /// - Note: The bounds may be infinite, but not their distance.
@@ -60,6 +60,41 @@ final class BinaryIntegerTestsOnRandom: XCTestCase {
         }
     }
 
+    func testRandomInRangeHasKnownBounds() {
+        func whereIs<T>(_ type: T.Type, randomness: consuming FuzzerInt) where T: BinaryInteger {
+            func check(_ expectation: Range<T>) {
+                guard !expectation.isEmpty else { return }
+                let last: T = expectation.upperBound - 1
+
+                var min = false
+                var max = false
+
+                while !(min && max) {
+                    let random = T.random(in: expectation, using: &randomness)!
+                    guard expectation.contains(random) else {  break }
+                    if random == expectation.lowerBound { min = true }
+                    if random == (((((((((last))))))))) { max = true }
+                }
+
+                Test().yay(min && max)
+            }
+
+            for index: IX in 0 ... 7 {
+                let min = T.random(through: Shift(Count(index)), using: &randomness)
+                let max = T.random(through: Shift(Count(index)), using: &randomness)
+                check(min <= max ? min..<max : max..<min)
+            }
+        }
+
+        for type in binaryIntegers {
+            whereIs(type, randomness: fuzzer)
+        }
+    }
+
+    //=------------------------------------------------------------------------=
+    // MARK: Tests x Closed Range
+    //=------------------------------------------------------------------------=
+
     /// - Note: The bounds may be infinite, but not their distance.
     func testRandomInClosedRange() {
         func whereIs<T>(_ type: T.Type, randomness: consuming FuzzerInt) where T: BinaryInteger {
@@ -97,6 +132,38 @@ final class BinaryIntegerTestsOnRandom: XCTestCase {
         }
     }
 
+    func testRandomInClosedRangeHasKnownBounds() {
+        func whereIs<T>(_ type: T.Type, randomness: consuming FuzzerInt) where T: BinaryInteger {
+            func check(_ expectation: ClosedRange<T>) {
+                var min = false
+                var max = false
+
+                while !(min && max) {
+                    let random = T.random(in: expectation, using: &randomness)
+                    guard expectation.contains(random) else {  break }
+                    if random == expectation.lowerBound { min = true }
+                    if random == expectation.upperBound { max = true }
+                }
+
+                Test().yay(min && max)
+            }
+
+            for index: IX in 0 ... 7 {
+                let min = T.random(through: Shift(Count(index)), using: &randomness)
+                let max = T.random(through: Shift(Count(index)), using: &randomness)
+                check(min <= max ? min...max : max...min)
+            }
+        }
+
+        for type in binaryIntegers {
+            whereIs(type, randomness: fuzzer)
+        }
+    }
+
+    //=------------------------------------------------------------------------=
+    // MARK: Tests x Bit Index
+    //=------------------------------------------------------------------------=
+
     func testRandomThroughBitIndex() {
         func whereIs<T>(_ type: T.Type, randomness: consuming FuzzerInt) where T: BinaryInteger {
             for index in 0 ..< (T.isArbitrary ? 128 : IX(size: T.self)!) {