Add more tests

src/jvmTest/kotlin/io/github/detekt/sarif4k/PropertyBagTest.kt

@@ -1,36 +1,64 @@
 package io.github.detekt.sarif4k
 
-import kotlinx.serialization.decodeFromString
-import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
+import org.junit.jupiter.api.assertThrows
 import org.junit.jupiter.params.ParameterizedTest
 import org.junit.jupiter.params.provider.Arguments
 import org.junit.jupiter.params.provider.MethodSource
+import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class PropertyBagTest {
 
     @ParameterizedTest
     @MethodSource("data")
-    fun encode(propertyBag: PropertyBag, json: String) {
-        assertEquals(json, Json.encodeToString(propertyBag))
+    fun encode(value: Map<String, Any?>, json: String) {
+        assertEquals(json, Json.encodeToString(PropertyBag.serializer(), PropertyBag(value)))
     }
 
     @ParameterizedTest
     @MethodSource("data")
-    fun decode(propertyBag: PropertyBag, json: String) {
-        assertEquals(propertyBag, Json.decodeFromString<PropertyBag>(json))
+    fun decode(value: Map<String, Any?>, json: String) {
+        assertEquals(PropertyBag(value), Json.decodeFromString(PropertyBag.serializer(), json))
+    }
+
+    @Test
+    fun noTags() {
+        assertEquals(null, PropertyBag(mapOf()).tags)
+    }
+
+    @Test
+    fun nullTags() {
+        assertEquals(null, PropertyBag(mapOf("tags" to null)).tags)
+    }
+
+    @Test
+    fun emptyTags() {
+        assertEquals(emptyList(), PropertyBag(mapOf("tags" to emptyList<Nothing>())).tags)
+    }
+
+    @Test
+    fun tags() {
+        assertEquals(listOf("foo", "bar"), PropertyBag(mapOf("tags" to listOf("foo", "bar"))).tags)
+    }
+
+    @Test
+    fun incorrectTags() {
+        assertThrows<ClassCastException> {
+            PropertyBag(mapOf("tags" to listOf(1))).tags
+        }
     }
 
     companion object {
         @JvmStatic
         fun data(): List<Arguments> {
             return listOf(
-                PropertyBag("foo" to null) to """{"foo":null}""",
-                PropertyBag("tags" to null) to """{"tags":null}""",
+                mapOf<String, Any?>() to """{}""",
+                mapOf("foo" to null) to """{"foo":null}""",
+                mapOf("foo" to mapOf("bar" to listOf("1", 2L, false, 3.5))) to """{"foo":{"bar":["1",2,false,3.5]}}""",
+                mapOf("tags" to null) to """{"tags":null}""",
+                mapOf("tags" to emptyList<Nothing>()) to """{"tags":[]}""",
             ).map { (first, second) -> Arguments.of(first, second) }
         }
     }
 }
-
-private fun PropertyBag(vararg values: Pair<String, Any?>) = PropertyBag(mapOf(*values))