Added Kover verification rule (#204)

Author: shanshin

build.gradle.kts

@@ -3,12 +3,14 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
  */
 
+import kotlinx.kover.gradle.plugin.dsl.MetricType
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import org.jetbrains.kotlin.gradle.tasks.KotlinNativeCompile
 
 plugins {
     id("kotlinx-io-publish") apply false
 
+    alias(libs.plugins.kover)
     alias(libs.plugins.bcv)
     alias(libs.plugins.dokka)
 }
@@ -37,3 +39,19 @@ subprojects {
 apiValidation {
     ignoredProjects.add("kotlinx-io-benchmarks")
 }
+
+dependencies {
+    kover(project(":kotlinx-io-core"))
+    kover(project(":kotlinx-io-bytestring"))
+}
+
+koverReport {
+    verify {
+        rule {
+            minBound(95, MetricType.LINE)
+
+            // we allow lower branch coverage, because not all checks in the internal code lead to errors
+            minBound(80, MetricType.BRANCH)
+        }
+    }
+}

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 kotlin = "1.9.0"
 java = "8"
 dokka = "1.8.20"
-kover = "0.7.1"
+kover = "0.7.3"
 bcv = "0.13.2"
 benchmark = "0.4.9"
 jmh = "1.36"