Test exception in worksheet evaluation

Author: Duhemm

language-server/test/dotty/tools/languageserver/WorksheetTest.scala

@@ -84,6 +84,13 @@ class WorksheetTest {
       .evaluate(m1, "1:val foo: Int = 1\nval bar: Int = 2")
   }
 
+  @Test def evaluationException: Unit = {
+    ws"""${m1}val foo = 1 / 0
+         val bar = 2""".withSource
+      .evaluateNonStrict(m1, "1:java.lang.ArithmeticException: / by zero",
+                             "2:val bar: Int = 2")
+  }
+
   @Test def worksheetCompletion(): Unit = {
     ws"""class Foo { def bar = 123 }
          val x = new Foo

language-server/test/dotty/tools/languageserver/util/CodeTester.scala

@@ -127,7 +127,19 @@ class CodeTester(sources: List[SourceWithPositions], actions: List[Action]) {
    * @see dotty.tools.languageserver.util.actions.WorksheetEvaluate
    */
   def evaluate(marker: CodeMarker, expected: String*): this.type =
-    doAction(new WorksheetEvaluate(marker, expected))
+    doAction(new WorksheetEvaluate(marker, expected, strict = true))
+
+  /**
+   * Triggers evaluation of the worksheet specified by `marker`, verifies that each line of output
+   * starts with `expected`.
+   *
+   * @param marker   A marker a identifies the worksheet to evaluate.
+   * @param expected The expected starts of output.
+   *
+   * @see dotty.tools.languageserver.util.actions.WorksheetEvaluate
+   */
+  def evaluateNonStrict(marker: CodeMarker, expected: String*): this.type =
+    doAction(new WorksheetEvaluate(marker, expected, strict = false))
 
   /**
    * Triggers evaluation of the worksheet specified by `marker`, then verifies that execution can be

language-server/test/dotty/tools/languageserver/util/actions/WorksheetEvaluate.scala

@@ -3,9 +3,9 @@ package dotty.tools.languageserver.util.actions
 import dotty.tools.languageserver.util.PositionContext
 import dotty.tools.languageserver.util.embedded.CodeMarker
 
-import org.junit.Assert.{assertEquals, fail}
+import org.junit.Assert.{assertEquals, assertTrue, fail}
 
-class WorksheetEvaluate(marker: CodeMarker, expected: Seq[String]) extends WorksheetAction {
+class WorksheetEvaluate(marker: CodeMarker, expected: Seq[String], strict: Boolean) extends WorksheetAction {
 
   private final val evaluationTimeoutMs = 30 * 1000
 
@@ -20,7 +20,13 @@ class WorksheetEvaluate(marker: CodeMarker, expected: Seq[String]) extends Works
       Thread.sleep(100)
     }
 
-    assertEquals(expected, getLogs(marker).init)
+    if (strict) {
+      assertEquals(expected, getLogs(marker).init)
+    } else {
+      expected.zip(getLogs(marker).init).foreach {
+        case (expected, message) => assertTrue(s"'$message' didn't start with '$expected'", message.startsWith(expected))
+      }
+    }
     client.log.clear()
   }