[java] minor optimization (IDEA-CR-16521)

java/java-tests/testSrc/com/intellij/lang/java/lexer/JavaKeywordsTest.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed 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 com.intellij.lang.java.lexer
+
+import com.intellij.pom.java.LanguageLevel
+import com.intellij.util.text.ByteArrayCharSequence
+import com.intellij.util.text.CharArrayCharSequence
+import org.junit.Test
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class JavaKeywordsTest {
+  @Test fun hardAndSoft() {
+    assertTrue(JavaLexer.isKeyword("char", LanguageLevel.JDK_1_9))
+    assertFalse(JavaLexer.isSoftKeyword("char", LanguageLevel.JDK_1_9))
+    assertFalse(JavaLexer.isKeyword("module", LanguageLevel.JDK_1_9))
+    assertTrue(JavaLexer.isSoftKeyword("module", LanguageLevel.JDK_1_9))
+  }
+
+  @Test fun sequences() {
+    assertTrue(JavaLexer.isSoftKeyword(ByteArrayCharSequence.convertToBytesIfAsciiString("module"), LanguageLevel.JDK_1_9))
+    assertTrue(JavaLexer.isSoftKeyword(CharArrayCharSequence("[module]".toCharArray(), 1, 7), LanguageLevel.JDK_1_9))
+  }
+
+  @Test fun nullTolerance() {
+    assertFalse(JavaLexer.isKeyword(null, LanguageLevel.JDK_1_3))
+    assertFalse(JavaLexer.isSoftKeyword(null, LanguageLevel.JDK_1_9))
+  }
+}