Fix parsing of the Measurement annotation in SuiteSourceGenerator (#127)

Author: Abduqodiri Qurbonzoda

integration/src/main/kotlin/kotlinx/benchmark/integration/AnnotationsSpecifier.kt

@@ -0,0 +1,26 @@
+package kotlinx.benchmark.integration
+
+class AnnotationsSpecifier {
+    private var isMeasurementSpecified: Boolean = false
+    private var iterations: Int? = null
+    private var time: Int? = null
+    private var timeUnit: String? = null
+
+    fun measurement(iterations: Int, time: Int, timeUnit: String) {
+        isMeasurementSpecified = true
+        this.iterations = iterations
+        this.time = time
+        this.timeUnit = timeUnit
+    }
+
+    fun replacementForLine(line: String): String {
+        val trimmedLine = line.trimStart()
+        val prefix = line.substring(0, line.length - trimmedLine.length)
+        return when {
+            isMeasurementSpecified && trimmedLine.startsWith("@Measurement") ->
+                "$prefix@Measurement($iterations, $time, $timeUnit)"
+            else ->
+                line
+        }
+    }
+}

integration/src/main/kotlin/kotlinx/benchmark/integration/Runner.kt

@@ -34,4 +34,16 @@ class Runner(
 
     private fun defaultArguments(): Array<String> = arrayOf("--stacktrace")
 
+    fun updateAnnotations(filePath: String, annotationsSpecifier: AnnotationsSpecifier.() -> Unit) {
+        val annotations = AnnotationsSpecifier().also(annotationsSpecifier)
+        val file = projectDir.resolve(filePath)
+        val updatedLines = file.readLines().map { annotations.replacementForLine(it) }
+        file.writeText(updatedLines.joinToString(separator = "\n"))
+    }
+
+    fun generatedDir(targetName: String, filePath: String, fileTestAction: (File) -> Unit) {
+        fileTestAction(
+            projectDir.resolve("build/benchmarks/${targetName}/sources/kotlinx/benchmark/generated").resolve(filePath)
+        )
+    }
 }

integration/src/test/kotlin/kotlinx/benchmark/integration/SuiteSourceGeneratorTest.kt

@@ -0,0 +1,23 @@
+package kotlinx.benchmark.integration
+
+import kotlin.test.*
+
+class SuiteSourceGeneratorTest : GradleTest() {
+    @Test
+    fun measurementAnnotation() {
+        project("kotlin-multiplatform", true).let { runner ->
+            runner.updateAnnotations("src/commonMain/kotlin/CommonBenchmark.kt") {
+                measurement(iterations = 5, time = 200, timeUnit = "BenchmarkTimeUnit.MILLISECONDS")
+            }
+
+            runner.run("nativeBenchmarkGenerate")
+
+            runner.generatedDir("native", "test/CommonBenchmark_Descriptor.kt") { descriptorFile ->
+                val text = descriptorFile.readText()
+                val parameters = "iterations = 5, iterationTime = IterationTime\\(200, BenchmarkTimeUnit.MILLISECONDS\\)"
+                    .replace(" ", "\\s+").toRegex()
+                assertTrue(text.contains(parameters), "Parameters: <$parameters> not found in <$text>")
+            }
+        }
+    }
+}

plugin/main/src/kotlinx/benchmark/gradle/SuiteSourceGenerator.kt

@@ -134,18 +134,18 @@ class SuiteSourceGenerator(val title: String, val module: ModuleDescriptor, val
         val outputTimeAnnotation = original.annotations.singleOrNull { it.fqName.toString() == outputTimeAnnotationFQN }
         val modeAnnotation = original.annotations.singleOrNull { it.fqName.toString() == modeAnnotationFQN }
 
-        val outputTimeUnitValue = outputTimeAnnotation?.argumentValue("value") as? EnumValue
+        val outputTimeUnitValue = outputTimeAnnotation?.argumentValue("value") as EnumValue?
         val outputTimeUnit = outputTimeUnitValue?.enumEntryName?.toString()
 
         @Suppress("UNCHECKED_CAST")
-        val modesValue = modeAnnotation?.argumentValue("value")?.value as? List<EnumValue>
+        val modesValue = modeAnnotation?.argumentValue("value")?.value as List<EnumValue>?
         val mode = modesValue?.single()?.enumEntryName?.toString()
 
-        val measureIterations = measureAnnotation?.argumentValue("iterations")?.value as? Int
-        val measureIterationTime = measureAnnotation?.argumentValue("time")?.value as? Int
-        val measureIterationTimeUnit = measureAnnotation?.argumentValue("timeUnit")?.value as? EnumValue
+        val measureIterations = measureAnnotation?.argumentValue("iterations")?.value as Int?
+        val measureIterationTime = measureAnnotation?.argumentValue("time")?.value as Int?
+        val measureIterationTimeUnit = measureAnnotation?.argumentValue("timeUnit") as EnumValue?
 
-        val warmupIterations = warmupAnnotation?.argumentValue("iterations")?.value as? Int
+        val warmupIterations = warmupAnnotation?.argumentValue("iterations")?.value as Int?
 
         val iterations = measureIterations
         val iterationTime = measureIterationTime
@@ -203,7 +203,7 @@ class SuiteSourceGenerator(val title: String, val module: ModuleDescriptor, val
                     val constant = annotation.argumentValue("value") 
                         ?: error("@Param annotation should have at least one default value")
                     @Suppress("UNCHECKED_CAST")
-                    val values = constant.value as? List<StringValue>
+                    val values = constant.value as List<StringValue>?
                         ?: error("@Param annotation should have at least one default value")
                     values
                 })