Added tests (#158)

Author: dstibbe

kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/TypesTest.kt

@@ -158,6 +158,52 @@ class TypesTest {
         assertEquals("audio/wav", decoded.mimeType)
     }
 
+    @Test
+    fun `should validate resource link content`() {
+        val resourceLink = ResourceLink(
+            mimeType = "application/pdf",
+            description = "This pdf is meant to be a resource link test",
+            name = "file01",
+            size = 76859L,
+            title = "This is a pdf",
+            uri = "file:///path/to/my_file.pdf",
+        )
+
+        with(resourceLink) {
+            assertEquals("application/pdf", mimeType)
+            assertEquals("This pdf is meant to be a resource link test", description)
+            assertEquals("file01", name)
+            assertEquals(76859L, size)
+            assertEquals("This is a pdf", title)
+            assertEquals("file:///path/to/my_file.pdf", uri)
+        }
+    }
+
+    @Test
+    fun `should serialize and deserialize resource link correctly`() {
+        val resourceLink = ResourceLink(
+            mimeType = "application/pdf",
+            description = "This pdf is meant to be a resource link test",
+            name = "file01",
+            size = 76859L,
+            title = "This is a pdf",
+            uri = "file:///path/to/my_file.pdf",
+        )
+
+        val json = McpJson.encodeToString<ContentBlock>(resourceLink)
+        val decoded = McpJson.decodeFromString<ContentBlock>(json)
+
+        assertIs<ResourceLink>(decoded)
+        with(resourceLink) {
+            assertEquals("application/pdf", mimeType)
+            assertEquals("This pdf is meant to be a resource link test", description)
+            assertEquals("file01", name)
+            assertEquals(76859L, size)
+            assertEquals("This is a pdf", title)
+            assertEquals("file:///path/to/my_file.pdf", uri)
+        }
+    }
+
     @Test
     fun `should validate embedded resource content`() {
         val resource = TextResourceContents(

kotlin-sdk-core/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/TypesUtilTest.kt

@@ -147,6 +147,28 @@ class TypesUtilTest {
         assertEquals("audio/mp3", decoded.mimeType)
     }
 
+    @Test
+    fun `should deserialize ResourceLink polymorphically`() {
+        val json = """
+            {
+              "type": "resource_link",
+              "uri": "file:///project/src/main.rs",
+              "name": "main.rs",
+              "description": "Primary application entry point",
+              "mimeType": "text/x-rust"
+            }
+        """.trimIndent()
+
+        val decoded = McpJson.decodeFromString<ContentBlock>(json)
+
+        assertIs<ResourceLink>(decoded)
+        assertEquals("resource_link", decoded.type)
+        assertEquals("file:///project/src/main.rs", decoded.uri)
+        assertEquals("main.rs", decoded.name)
+        assertEquals("Primary application entry point", decoded.description)
+        assertEquals("text/x-rust", decoded.mimeType)
+    }
+
     @Test
     fun `should deserialize EmbeddedResource polymorphically`() {
         val json =