add the forgotten patmat test

Author: liufengyun

test/test/transform/PatmatExhaustivityTest.scala

@@ -0,0 +1,90 @@
+package test.transform
+
+import java.io._
+
+import scala.io.Source._
+import scala.reflect.io.Directory
+import org.junit.Test
+import dotty.tools.dotc.Main
+import dotty.tools.dotc.reporting.ClassicReporter
+
+class PatmatExhaustivityTest {
+  val testsDir = "./tests/patmat"
+  // stop-after: patmatexhaust-huge.scala crash compiler
+  val options = List("-color:never", "-Ystop-after:splitter", "-Ycheck-all-patmat")
+
+  private def compileFile(file: File) = {
+    val stringBuffer = new StringWriter()
+    val reporter = new ClassicReporter(writer = new PrintWriter(stringBuffer))
+
+    try {
+      Main.process((file.getPath::options).toArray, reporter, null)
+    } catch {
+      case e: Throwable =>
+        println(s"Compile $file exception:")
+        e.printStackTrace()
+    }
+
+    val actual = stringBuffer.toString.trim
+    val checkFilePath = file.getAbsolutePath.stripSuffix(".scala") + ".check"
+    val checkContent =
+      if (new File(checkFilePath).exists)
+        fromFile(checkFilePath).getLines.mkString("\n").trim
+      else ""
+
+    (file, checkContent, actual)
+  }
+
+  /** A single test with multiple files grouped in a folder */
+  private def compileDir(file: File) = {
+    val stringBuffer = new StringWriter()
+    val reporter = new ClassicReporter(writer = new PrintWriter(stringBuffer))
+
+    val files = Directory(file.getPath).list.toList
+      .filter(f => f.extension == "scala" || f.extension == "java" )
+      .map(_.jfile.getPath)
+
+    try {
+      Main.process((options ++ files).toArray, reporter, null)
+    } catch {
+      case e: Throwable =>
+        println(s"Compile $file exception:")
+        e.printStackTrace()
+    }
+
+    val actual = stringBuffer.toString.trim
+    val checkFilePath = file.getPath + File.separator + "expected.check"
+    val checkContent =
+      if (new File(checkFilePath).exists)
+        fromFile(checkFilePath).getLines.mkString("\n").trim
+      else ""
+
+    (file, checkContent, actual)
+  }
+
+  @Test def patmatExhaustivity: Unit = {
+    val res = Directory(testsDir).list.toList
+      .filter(f => f.extension == "scala" || f.isDirectory)
+      .map { f =>
+        if (f.isDirectory)
+          compileDir(f.jfile)
+        else
+          compileFile(f.jfile)
+      }
+
+    val failed = res.filter { case (_, expected, actual) => expected != actual }
+    val ignored = Directory(testsDir).list.toList.filter(_.extension == "ignore")
+
+    failed.foreach { case (file, expected, actual) =>
+      println(s"\n----------------- incorrect output for $file --------------\n" +
+        s"Expected:\n-------\n$expected\n\nActual\n----------\n$actual\n"
+      )
+    }
+
+    val msg = s"Total: ${res.length + ignored.length}, Failed: ${failed.length}, Ignored: ${ignored.length}"
+
+    assert(failed.length == 0, msg)
+
+    println(msg)
+  }
+}

tests/patmat/i947.check

@@ -1,4 +1,4 @@
 ./tests/patmat/i947.scala:10: warning: unreachable code
       case ys: List[d18383] => false
-                           ^
+             ^
 one warning found