1 files changed, 60 insertions, 0 deletions
diff --git a/formats/json-tests/jsTest/src/kotlinx/serialization/json/DynamicToLongTest.kt b/formats/json-tests/jsTest/src/kotlinx/serialization/json/DynamicToLongTest.kt
new file mode 100644
index 00000000..2daf0bb2
--- /dev/null
+++ b/formats/json-tests/jsTest/src/kotlinx/serialization/json/DynamicToLongTest.kt
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2017-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json
+
+import kotlinx.serialization.*
+import kotlin.test.*
+
+/**
+ * [https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER]
+ */
+internal const val MAX_SAFE_INTEGER: Double = 9007199254740991.toDouble() // 2^53 - 1
+
+class DynamicToLongTest {
+
+    @Serializable
+    data class HasLong(val l: Long)
+
+    private fun test(dynamic: dynamic, expectedResult: Result<Long>) {
+        val parsed = kotlin.runCatching { Json.decodeFromDynamic(HasLong.serializer(), dynamic).l }
+        assertEquals(expectedResult.isSuccess, parsed.isSuccess, "Results are different")
+        parsed.onSuccess { assertEquals(expectedResult.getOrThrow(), it) }
+        // to compare without message
+        parsed.onFailure { assertSame(expectedResult.exceptionOrNull()!!::class, it::class) }
+    }
+
+    private fun shouldFail(dynamic: dynamic) = test(dynamic,  Result.failure(SerializationException("")))
+
+    @Test
+    fun canParseNotSoBigLongs() {
+        test(js("{l:1}"), Result.success(1))
+        test(js("{l:0}"), Result.success(0))
+        test(js("{l:-1}"), Result.success(-1))
+    }
+
+    @Test
+    fun ignoresIncorrectValues() {
+        shouldFail(js("{l:0.5}"))
+        shouldFail(js("{l: Math.PI}"))
+        shouldFail(js("{l: NaN}"))
+        shouldFail(js("""{l: "a string"}"""))
+        shouldFail(js("{l:Infinity}"))
+        shouldFail(js("{l:+Infinity}"))
+        shouldFail(js("{l:-Infinity}"))
+    }
+
+    @Test
+    fun handlesEdgyValues() {
+        test(js("{l:Number.MAX_SAFE_INTEGER}"), Result.success(MAX_SAFE_INTEGER.toLong()))
+        test(js("{l:Number.MAX_SAFE_INTEGER - 1}"), Result.success(MAX_SAFE_INTEGER.toLong() - 1))
+        test(js("{l:-Number.MAX_SAFE_INTEGER}"), Result.success(-MAX_SAFE_INTEGER.toLong()))
+        shouldFail(js("{l: Number.MAX_SAFE_INTEGER + 1}"))
+        shouldFail(js("{l: Number.MAX_SAFE_INTEGER + 2}"))
+        shouldFail(js("{l: -Number.MAX_SAFE_INTEGER - 1}"))
+        shouldFail(js("{l: 2e100}"))
+        shouldFail(js("{l: 2e100 + 1}"))
+        test(js("{l: Math.pow(2, 53) - 1}"), Result.success(MAX_SAFE_INTEGER.toLong()))
+    }
+}