Setup Kover for validation of each module (#2674)

Also, slightly increased coverage

Resolves #2634

Author: shanshin

build.gradle.kts

@@ -12,6 +12,7 @@ plugins {
     id("org.jetbrains.dokka")
     id("benchmark-conventions")
     id("publishing-check-conventions")
+    id("kover-conventions")
 
     alias(libs.plugins.serialization) apply false
 }
@@ -136,12 +137,6 @@ subprojects {
     apply(plugin = "bom-conventions")
 }
 
-// == Kover setup ==
-subprojects {
-    if (project.name in uncoveredProjects) return@subprojects
-    apply(plugin = "kover-conventions")
-}
-
 // == Dokka setup ==
 subprojects {
     if (name in documentedSubprojects) {
@@ -200,5 +195,3 @@ val documentedSubprojects get() = setOf("kotlinx-serialization-core",
     "kotlinx-serialization-properties",
     "kotlinx-serialization-hocon",
     "kotlinx-serialization-protobuf")
-
-val uncoveredProjects get() = setOf("kotlinx-serialization-bom", "benchmark", "guide", "kotlinx-serialization-json-okio", "kotlinx-serialization-json-io")

buildSrc/src/main/kotlin/kover-conventions.gradle.kts

@@ -10,15 +10,43 @@ kover {
         disable()
     }
 
+    currentProject {
+        projectsForCoverageVerification.forEach { (variantName, _) ->
+            // copy the `main` variant for each module to check the coverage only in its section
+            copyVariant(variantName, "main")
+        }
+    }
+
+    merge {
+        // collect common coverage for all projects (except excluded) in `main` variant
+        subprojects { subproject ->
+            subproject.path !in uncoveredProjects
+        }
+        createVariant("main") { add("jvm", optional = true) }
+    }
+
     reports {
-        verify {
-            rule("Minimal line coverage rate in percents") {
+        total.verify.rule("Total coverage") {
+            minBound(90)
+        }
+
+        projectsForCoverageVerification.forEach { (variantName, projectPath) ->
+            variant(variantName) {
+                filters.includes.projects.add(projectPath)
 
-                // Core is mainly uncovered because a lot of serializers are tested with JSON
-                val minPercentage = if (project.name.contains("core") || project.name.contains("properties") || project.name.contains("json-okio")) 44 else 80
-                minBound(minPercentage)
-                // valueType is 'COVERED_LINES_PERCENTAGE' by default
+                // verify the coverage individually for each module by `check` task
+                verify {
+                    onCheck = true
+                    rule("Coverage for $projectPath") {
+                        minBound(85)
+                    }
+                }
             }
         }
     }
 }
+
+
+val uncoveredProjects get() = setOf(":kotlinx-serialization-bom", ":benchmark", ":guide")
+// map: variant name -> project path
+val projectsForCoverageVerification get() = mapOf("core" to ":kotlinx-serialization-core", "json" to ":kotlinx-serialization-json", "jsonOkio" to ":kotlinx-serialization-json-okio", "cbor" to ":kotlinx-serialization-cbor", "hocon" to ":kotlinx-serialization-hocon", "properties" to ":kotlinx-serialization-properties", "protobuf" to ":kotlinx-serialization-protobuf", "io" to ":kotlinx-serialization-json-io")

formats/json-io/commonTest/src/kotlinx/serialization/json/io/IoTests.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2017-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json.io
+
+import kotlinx.io.*
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.*
+import kotlinx.serialization.json.io.internal.*
+import kotlin.test.*
+
+class IoTests {
+
+    @Serializable
+    data class Simple(val i: Int)
+
+    @Test
+    fun testSurrogate() {
+        val text = "\uD83D\uDE03"
+        val originalChars = text.toCharArray()
+
+        val buffer = Buffer()
+        buffer.writeString(text)
+        val reader = IoSerialReader(buffer)
+
+        val readArray = CharArray(2)
+        assertEquals(1, reader.read(readArray, 0, 1) )
+        assertEquals(1, reader.read(readArray, 1, 1) )
+
+        assertContentEquals(originalChars, readArray)
+    }
+
+
+    @Test
+    fun testEncodingAndDecoding() {
+        val json = "{\"i\":42}"
+        val value = Simple(42)
+        val buffer = Buffer()
+        Json.encodeToSink(value, buffer)
+        val encoded = buffer.readString()
+        assertEquals(json, encoded)
+
+        buffer.writeString(encoded)
+        val decoded = Json.decodeFromSource<Simple>(buffer)
+        assertEquals(value, decoded)
+
+        assertTrue(buffer.exhausted())
+    }
+
+    @Test
+    fun testDecodeSequence() {
+        val json = "{\"i\":1}{\"i\":2}"
+        val value1 = Simple(1)
+        val value2 = Simple(2)
+        val buffer = Buffer()
+        buffer.writeString(json)
+        val decoded = Json.decodeSourceToSequence<Simple>(buffer).toList()
+
+        assertTrue(buffer.exhausted())
+        assertEquals(2, decoded.size)
+        assertEquals(listOf(value1, value2), decoded)
+
+        buffer.writeString(json)
+        val decodedExplicit = Json.decodeSourceToSequence(buffer, Simple.serializer()).toList()
+        assertTrue(buffer.exhausted())
+        assertEquals(2, decodedExplicit.size)
+        assertEquals(listOf(value1, value2), decodedExplicit)
+    }
+}

formats/json-okio/commonTest/src/kotlinx/serialization/json/okio/internal/OkioTests.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2017-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json.okio.internal
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.*
+import kotlinx.serialization.json.okio.*
+import okio.*
+import kotlin.test.*
+
+class OkioTests {
+
+    @Serializable
+    data class Simple(val i: Int)
+
+    @Test
+    fun testSurrogate() {
+        val text = "\uD83D\uDE03"
+        val originalChars = text.toCharArray()
+
+        val buffer = Buffer()
+        buffer.writeUtf8(text)
+        val reader = OkioSerialReader(buffer)
+
+        val readArray = CharArray(2)
+        assertEquals(1, reader.read(readArray, 0, 1) )
+        assertEquals(1, reader.read(readArray, 1, 1) )
+
+        assertContentEquals(originalChars, readArray)
+    }
+
+
+    @Test
+    fun testEncodingAndDecoding() {
+        val json = "{\"i\":42}"
+        val value = Simple(42)
+        val buffer = Buffer()
+        Json.encodeToBufferedSink(value, buffer)
+        val encoded = buffer.readUtf8()
+        assertEquals(json, encoded)
+
+        buffer.writeUtf8(encoded)
+        val decoded = Json.decodeFromBufferedSource<Simple>(buffer)
+        assertEquals(value, decoded)
+
+        assertTrue(buffer.exhausted())
+    }
+
+    @Test
+    fun testDecodeSequence() {
+        val json = "{\"i\":1}{\"i\":2}"
+        val value1 = Simple(1)
+        val value2 = Simple(2)
+        val buffer = Buffer()
+        buffer.writeUtf8(json)
+        val decoded = Json.decodeBufferedSourceToSequence<Simple>(buffer).toList()
+
+        assertTrue(buffer.exhausted())
+        assertEquals(2, decoded.size)
+        assertEquals(listOf(value1, value2), decoded)
+
+        buffer.writeUtf8(json)
+        val decodedExplicit = Json.decodeBufferedSourceToSequence(buffer, Simple.serializer()).toList()
+        assertTrue(buffer.exhausted())
+        assertEquals(2, decodedExplicit.size)
+        assertEquals(listOf(value1, value2), decodedExplicit)
+    }
+}

formats/properties/commonTest/src/kotlinx/serialization/properties/PropertiesTest.kt

@@ -7,6 +7,7 @@ package kotlinx.serialization.properties
 
 import kotlinx.serialization.*
 import kotlinx.serialization.builtins.*
+import kotlinx.serialization.modules.*
 import kotlin.test.*
 
 class PropertiesTest {
@@ -107,6 +108,12 @@ class PropertiesTest {
         assertEquals(emptyMap(), Properties.encodeToMap(Unit.serializer(), Unit))
     }
 
+    @Test
+    fun testUnitIsEmptyMapModule() {
+        val module = SerializersModule {}
+        assertEquals(emptyMap(), Properties(module).encodeToMap(Unit.serializer(), Unit))
+    }
+
     @Test
     fun testList() {
         val data = Data(listOf("element1"), "property")

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 kotlin = "2.0.0"
-kover = "0.8.0-Beta2"
+kover = "0.8.2"
 dokka = "1.9.20"
 knit = "0.5.0"
 bcv = "0.15.0-Beta.2"