BigInt tests

Author: j-f1

IntegrationTests/TestSuites/Sources/PrimaryTests/main.swift

@@ -830,4 +830,35 @@ try test("Symbols") {
     try expectEqual(JSObject.global.Object.isInstanceOf(hasInstanceClass), true)
 }
 
+try test("BigInt") {
+    func expectPassesThrough(signed value: Int64) throws {
+        let bigInt = JSBigInt(value)
+        try expectEqual(bigInt.description, value.description)
+    }
+
+    func expectPassesThrough(unsigned value: UInt64) throws {
+        let bigInt = JSBigInt(unsigned: value)
+        try expectEqual(bigInt.description, value.description)
+    }
+
+    try expectPassesThrough(signed: 0)
+    try expectPassesThrough(signed: 1 << 62)
+    try expectPassesThrough(signed: -2305)
+    for _ in 0 ..< 100 {
+        try expectPassesThrough(signed: .random(in: .min ... .max))
+    }
+    try expectPassesThrough(signed: .min)
+    try expectPassesThrough(signed: .max)
+
+    try expectPassesThrough(unsigned: 0)
+    try expectPassesThrough(unsigned: 1 << 62)
+    try expectPassesThrough(unsigned: 1 << 63)
+    try expectPassesThrough(unsigned: .min)
+    try expectPassesThrough(unsigned: .max)
+    try expectPassesThrough(unsigned: ~0)
+    for _ in 0 ..< 100 {
+        try expectPassesThrough(unsigned: .random(in: .min ... .max))
+    }
+}
+
 Expectation.wait(expectations)