Actualized work with pre type of text - now it is possible to use language for formatting of text

src/commonTest/kotlin/com/github/insanusmokrassar/TelegramBotAPI/utils/StringFormattingTests.kt

@@ -0,0 +1,36 @@
+package com.github.insanusmokrassar.TelegramBotAPI.utils
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class StringFormattingTests {
+    @Test
+    fun testThatPreEscapingWorksCorrectly() {
+        val originalHelloWorld = """
+                fun main() {
+                    println("Hello world")
+                }
+            """.replace("                ", "")
+        val helloWorldLanguage = "kotlin"
+        assertEquals(
+            "<pre><code class=\"language-$helloWorldLanguage\">$originalHelloWorld</code></pre>",
+            originalHelloWorld.preHTML(
+                helloWorldLanguage
+            )
+        )
+        assertEquals(
+            "<pre>$originalHelloWorld</pre>",
+            originalHelloWorld.preHTML()
+        )
+        assertEquals(
+            "```$helloWorldLanguage\n$originalHelloWorld\n```",
+            originalHelloWorld.preMarkdown(
+                helloWorldLanguage
+            )
+        )
+        assertEquals(
+            "```\n$originalHelloWorld\n```",
+            originalHelloWorld.preMarkdown()
+        )
+    }
+}