Expose a means to disable boolean settings

Enables `-Yboolean-setting:{true,false}`. This will be exploited
in the next commit to enable one to turn off a single component
of a group setting, such as `-Xlint` or `-optimize`.

1 files changed, 28 insertions, 0 deletions

diff --git a/test/junit/scala/tools/nsc/settings/SettingsTest.scala b/test/junit/scala/tools/nsc/settings/SettingsTest.scala
new file mode 100644
index 0000000000..4b0e58ff79
--- /dev/null
+++ b/test/junit/scala/tools/nsc/settings/SettingsTest.scala
@@ -0,0 +1,28 @@
+package scala.tools.nsc
+package settings
+
+import org.junit.Assert._
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import scala.tools.testing.AssertUtil.assertThrows
+
+@RunWith(classOf[JUnit4])
+class SettingsTest {
+  @Test def booleanSettingColon() {
+    def check(args: String*): MutableSettings#BooleanSetting = {
+      val s = new MutableSettings(msg => throw new IllegalArgumentException(msg))
+      val b1 = new s.BooleanSetting("-Ytest-setting", "")
+      s.allSettings += b1
+      val (ok, residual) = s.processArguments(args.toList, processAll = true)
+      assert(residual.isEmpty)
+      b1
+    }
+    assertTrue(check("-Ytest-setting").value)
+    assertTrue(check("-Ytest-setting:true").value)
+    assertTrue(check("-Ytest-setting:TRUE").value)
+    assertFalse(check("-Ytest-setting:false").value)
+    assertFalse(check("-Ytest-setting:FALSE").value)
+    assertThrows[IllegalArgumentException](check("-Ytest-setting:rubbish"))
+  }
+}