Refactor getting the detekt version for readability (#2387)

detekt-core/src/main/kotlin/io/gitlab/arturbosch/detekt/core/DebugUtils.kt

@@ -1,6 +1,5 @@
 package io.gitlab.arturbosch.detekt.core
 
-import java.io.IOException
 import java.net.URL
 import java.util.jar.Manifest
 
@@ -9,21 +8,11 @@ fun whichOS(): String = System.getProperty("os.name")
 fun whichJava(): String = System.getProperty("java.runtime.version")
 
 fun whichDetekt(): String? {
-    for (resource in Detektor::class.java.classLoader.getResources("META-INF/MANIFEST.MF")) {
-        try {
-            val version = readDetektVersionInManifest(resource)
-            if (version != null) {
-                return version
-            }
-        } catch (_: IOException) {
-            // we search for the manifest with the detekt version
-        }
-    }
-    return null
-}
+    fun readVersion(resource: URL): String? = resource.openStream()
+        .use { Manifest(it).mainAttributes.getValue("DetektVersion") }
 
-private fun readDetektVersionInManifest(resource: URL) =
-        resource.openStream().use {
-            Manifest(it).mainAttributes
-                    .getValue("DetektVersion")
-        }
+    return Detektor::class.java.classLoader.getResources("META-INF/MANIFEST.MF")
+        .asSequence()
+        .mapNotNull { runCatching { readVersion(it) }.getOrNull() }
+        .firstOrNull()
+}