3 files changed, 44 insertions, 2 deletions

diff --git a/opendc-trace/opendc-trace-gwf/build.gradle.kts b/opendc-trace/opendc-trace-gwf/build.gradle.kts
index 1105a465..0c041439 100644
--- a/opendc-trace/opendc-trace-gwf/build.gradle.kts
+++ b/opendc-trace/opendc-trace-gwf/build.gradle.kts
@@ -31,4 +31,6 @@ dependencies {
     api(projects.opendcTrace.opendcTraceApi)
 
     implementation(libs.jackson.dataformat.csv)
+
+    testImplementation(projects.opendcTrace.opendcTraceTestkit)
 }
diff --git a/opendc-trace/opendc-trace-gwf/src/main/kotlin/org/opendc/trace/gwf/GwfTaskTableReader.kt b/opendc-trace/opendc-trace-gwf/src/main/kotlin/org/opendc/trace/gwf/GwfTaskTableReader.kt
index 007ab90a..f9a171e9 100644
--- a/opendc-trace/opendc-trace-gwf/src/main/kotlin/org/opendc/trace/gwf/GwfTaskTableReader.kt
+++ b/opendc-trace/opendc-trace-gwf/src/main/kotlin/org/opendc/trace/gwf/GwfTaskTableReader.kt
@@ -37,15 +37,24 @@ import java.util.regex.Pattern
  * A [TableReader] implementation for the GWF format.
  */
 internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
+    /**
+     * A flag to indicate whether a single row has been read already.
+     */
+    private var isStarted = false
+
     init {
         parser.schema = schema
     }
 
     override fun nextRow(): Boolean {
+        if (!isStarted) {
+            isStarted = true
+        }
+
         // Reset the row state
         reset()
 
-        if (!nextStart()) {
+        if (parser.isClosed || !nextStart()) {
             return false
         }
 
@@ -84,7 +93,7 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     override fun isNull(index: Int): Boolean {
-        check(index in 0..COL_DEPS) { "Invalid column" }
+        require(index in 0..COL_DEPS) { "Invalid column" }
         return false
     }
 
@@ -93,6 +102,7 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     override fun getInt(index: Int): Int {
+        checkActive()
         return when (index) {
             COL_REQ_NPROC -> reqNProcs
             COL_NPROC -> nProcs
@@ -113,6 +123,7 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     override fun getString(index: Int): String? {
+        checkActive()
         return when (index) {
             COL_JOB_ID -> jobId
             COL_WORKFLOW_ID -> workflowId
@@ -125,6 +136,7 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     override fun getInstant(index: Int): Instant? {
+        checkActive()
         return when (index) {
             COL_SUBMIT_TIME -> submitTime
             else -> throw IllegalArgumentException("Invalid column")
@@ -132,6 +144,7 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     override fun getDuration(index: Int): Duration? {
+        checkActive()
         return when (index) {
             COL_RUNTIME -> runtime
             else -> throw IllegalArgumentException("Invalid column")
@@ -147,6 +160,7 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     override fun <T> getSet(index: Int, elementType: Class<T>): Set<T>? {
+        checkActive()
         return when (index) {
             COL_DEPS -> TYPE_DEPS.convertTo(dependencies, elementType)
             else -> throw IllegalArgumentException("Invalid column")
@@ -158,6 +172,13 @@ internal class GwfTaskTableReader(private val parser: CsvParser) : TableReader {
     }
 
     /**
+     * Helper method to check if the reader is active.
+     */
+    private fun checkActive() {
+        check(isStarted && !parser.isClosed) { "No active row. Did you call nextRow()?" }
+    }
+
+    /**
      * The pattern used to parse the parents.
      */
     private val pattern = Pattern.compile("\\s+")
diff --git a/opendc-trace/opendc-trace-gwf/src/test/kotlin/org/opendc/trace/gwf/GwfTraceFormatTest.kt b/opendc-trace/opendc-trace-gwf/src/test/kotlin/org/opendc/trace/gwf/GwfTraceFormatTest.kt
index dd0e6066..a8c3a715 100644
--- a/opendc-trace/opendc-trace-gwf/src/test/kotlin/org/opendc/trace/gwf/GwfTraceFormatTest.kt
+++ b/opendc-trace/opendc-trace-gwf/src/test/kotlin/org/opendc/trace/gwf/GwfTraceFormatTest.kt
@@ -24,7 +24,10 @@ package org.opendc.trace.gwf
 
 import org.junit.jupiter.api.*
 import org.junit.jupiter.api.Assertions.*
+import org.opendc.trace.TableColumn
+import org.opendc.trace.TableReader
 import org.opendc.trace.conv.*
+import org.opendc.trace.testkit.TableReaderTestKit
 import java.nio.file.Paths
 import java.time.Duration
 import java.time.Instant
@@ -32,6 +35,7 @@ import java.time.Instant
 /**
  * Test suite for the [GwfTraceFormat] class.
  */
+@DisplayName("GWF TraceFormat")
 internal class GwfTraceFormatTest {
     private val format = GwfTraceFormat()
 
@@ -88,4 +92,19 @@ internal class GwfTraceFormatTest {
             { assertEquals(setOf("4", "5", "6"), reader.getSet(TASK_PARENTS, String::class.java)) },
         )
     }
+
+    @DisplayName("TableReader for Tasks")
+    @Nested
+    inner class TasksTableReaderTest : TableReaderTestKit() {
+        override lateinit var reader: TableReader
+        override lateinit var columns: List<TableColumn>
+
+        @BeforeEach
+        fun setUp() {
+            val path = Paths.get(checkNotNull(GwfTraceFormatTest::class.java.getResource("/trace.gwf")).toURI())
+
+            columns = format.getDetails(path, TABLE_TASKS).columns
+            reader = format.newReader(path, TABLE_TASKS, null)
+        }
+    }
 }