allow extensions to get the correct stack trace

better implementation ideas here would be nice

2 files changed, 79 insertions, 3 deletions

diff --git a/src/main/scala/org/perl8/test/TestMore.scala b/src/main/scala/org/perl8/test/TestMore.scala
index fa3b6d4..487b023 100644
--- a/src/main/scala/org/perl8/test/TestMore.scala
+++ b/src/main/scala/org/perl8/test/TestMore.scala
@@ -10,6 +10,7 @@ class TestMore (plan: Option[Plan] = None) extends Test with DelayedInit {
     this(Some(plan))
 
   def delayedInit (body: => Unit) {
+    level    = 0
     todo     = NoMessage
     builder  = new TestBuilder(plan, "", NoMessage)
     testBody = () => body
@@ -133,9 +134,16 @@ class TestMore (plan: Option[Plan] = None) extends Test with DelayedInit {
   }
 
   private def failed (desc: Message) {
-    val caller = Thread.currentThread.getStackTrace.drop(1).find(frame => {
-      frame.getFileName != "TestMore.scala"
-    })
+    val stack = Thread.currentThread.getStackTrace.drop(1)
+    def findIdx (level: Int, start: Int): Int = {
+      val idx = stack.indexWhere({ frame =>
+        frame.getFileName != "TestMore.scala"
+      }, start)
+
+      if (level == 0) { idx } else { findIdx(level - 1, idx + 1) }
+    }
+    val idx = findIdx(level, 0)
+    val caller = stack.drop(idx).headOption
     val (file, line) = caller match {
       case Some(frame) => (frame.getFileName, frame.getLineNumber)
       case None        => ("<unknown file>", "<unknown line>")
@@ -151,6 +159,19 @@ class TestMore (plan: Option[Plan] = None) extends Test with DelayedInit {
     builder.diag(message + trace)
   }
 
+  def withLevel[T] (newLevel: Int)(body: => T): T = {
+    val oldLevel = level
+    try {
+      // XXX "+4" is something of a hack, not sure how stable it will be
+      level += newLevel + 4
+      body
+    }
+    finally {
+      level = oldLevel
+    }
+  }
+
+  private var level: Int           = _
   private var todo: Message        = _
   private var builder: TestBuilder = _
   private var testBody: () => Unit = _
diff --git a/src/test/scala/org/perl8/test/ExtensionTest.scala b/src/test/scala/org/perl8/test/ExtensionTest.scala
new file mode 100644
index 0000000..e616d3e
--- /dev/null
+++ b/src/test/scala/org/perl8/test/ExtensionTest.scala
@@ -0,0 +1,55 @@
+package org.perl8.test
+
+import java.io.ByteArrayOutputStream
+
+trait NumberZero { this: TestMore =>
+  def is_zero (i: Int, desc: String): Boolean = {
+    withLevel(1) {
+      is(i, 0, desc)
+    }
+  }
+}
+
+trait NumberZeroWrapped extends NumberZero { this: TestMore =>
+  def isZero (i: Int): Boolean = {
+    withLevel(1) {
+      is_zero(i, "the number is zero")
+    }
+  }
+}
+
+class ExtensionTest extends TestMore {
+  private class ExtensionTestTest extends TestMore with NumberZeroWrapped {
+    is_zero(0, "it's zero")
+    is_zero(1, "it's not zero")
+    isZero(0)
+    isZero(1)
+  }
+
+  val out = new ByteArrayOutputStream
+  val exitCode = Console.withOut(out) {
+    Console.withErr(out) {
+      (new ExtensionTestTest).run
+    }
+  }
+
+  is(exitCode, 2)
+
+  val tap =
+    "ok 1 - it's zero\n" +
+    "not ok 2 - it's not zero\n" +
+    "#   Failed test 'it's not zero'\n" +
+    "#   at ExtensionTest.scala line 24.\n" +
+    "#          got: '1'\n" +
+    "#     expected: '0'\n" +
+    "ok 3 - the number is zero\n" +
+    "not ok 4 - the number is zero\n" +
+    "#   Failed test 'the number is zero'\n" +
+    "#   at ExtensionTest.scala line 26.\n" +
+    "#          got: '1'\n" +
+    "#     expected: '0'\n" +
+    "1..4\n" +
+    "# Looks like you failed 2 tests of 4.\n"
+
+  is(out.toString, tap)
+}