add tests for label parsers

Author: mengxr

mllib/src/test/scala/org/apache/spark/mllib/util/LabelParsersSuite.scala

@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.mllib.util
+
+import org.scalatest.FunSuite
+
+class LabelParsersSuite extends FunSuite {
+  test("binary label parser") {
+    for (parser <- Seq(BinaryLabelParser, BinaryLabelParser.getInstance())) {
+      assert(parser.parse("+1") === 1.0)
+      assert(parser.parse("1") === 1.0)
+      assert(parser.parse("0") === 0.0)
+      assert(parser.parse("-1") === 0.0)
+    }
+  }
+
+  test("multiclass label parser") {
+    for (parser <- Seq(MulticlassLabelParser, MulticlassLabelParser.getInstance())) {
+      assert(parser.parse("0") == 0.0)
+      assert(parser.parse("+1") === 1.0)
+      assert(parser.parse("1") === 1.0)
+      assert(parser.parse("2") === 2.0)
+      assert(parser.parse("3") === 3.0)
+    }
+  }
+}