1 files changed, 119 insertions, 0 deletions
diff --git a/tests/wifitests/src/com/android/server/wifi/util/StringUtilTest.java b/tests/wifitests/src/com/android/server/wifi/util/StringUtilTest.java
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+++ b/tests/wifitests/src/com/android/server/wifi/util/StringUtilTest.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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.android.server.wifi.util;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import android.test.suitebuilder.annotation.SmallTest;
+
+import org.junit.Test;
+
+/**
+ * Unit tests for {@link com.android.server.wifi.util.StringUtil}.
+ */
+@SmallTest
+public class StringUtilTest {
+    static final byte ASCII_UNIT_SEPARATOR = 31;
+    static final byte ASCII_DEL = 127;
+
+    /** Verifies that isAsciiPrintable() does not crash when passed a null array. */
+    @Test
+    public void nullArrayDoesNotCauseCrash() {
+        assertTrue(StringUtil.isAsciiPrintable(null));
+    }
+
+    /** Verifies that isAsciiPrintable() considers an empty array to be printable. */
+    @Test
+    public void emptyArrayIsPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{}));
+    }
+
+    /** Verifies that isAsciiPrintable() considers a single printable byte to be printable. */
+    @Test
+    public void arrayWithSinglePrintableByteIsPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'a'}));
+    }
+
+    /**
+     * Verifies that isAsciiPrintable() considers an array of multiple printable bytes to be
+     * printable.
+     */
+    @Test
+    public void arrayWithMultiplePrintableBytesIsPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'a', 'b'}));
+    }
+
+    /**
+     * Verifies that isAsciiPrintable() considers bell, form feed, newline, horizontal tab,
+     * and vertical tab to be printable.
+     */
+    @Test
+    public void printableControlCharactersAreConsideredPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{0x07}));  // bell
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'\f'}));  // form feed
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'\n'}));
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'\t'}));
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{0x0b}));  // vertical tab
+    }
+
+    /** Verifies that isAsciiPrintable() considers a newline to be printable. */
+    @Test
+    public void arrayWithNewlineIsPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'\n'}));
+    }
+
+    /** Verifies that isAsciiPrintable() considers a space to be printable. */
+    @Test
+    public void arrayWithSpaceIsPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{' '}));
+    }
+
+    /** Verifies that isAsciiPrintable() considers a tilde to be printable. */
+    @Test
+    public void arrayWithTildeIsPrintable() {
+        assertTrue(StringUtil.isAsciiPrintable(new byte[]{'~'}));
+    }
+
+    /** Verifies that isAsciiPrintable() considers a null to be unprintable. */
+    @Test
+    public void arrayWithNullByteIsNotPrintable() {
+        assertFalse(StringUtil.isAsciiPrintable(new byte[]{0}));
+    }
+
+    /** Verifies that isAsciiPrintable() considers (space-1) to be unprintable. */
+    @Test
+    public void arrayWithUnitSeparatorIsNotPrintable() {
+        assertFalse(StringUtil.isAsciiPrintable(new byte[]{ASCII_UNIT_SEPARATOR}));
+    }
+
+    /** Verifies that isAsciiPrintable() considers (tilde+1) to be unprintable. */
+    @Test
+    public void arrayWithDelIsNotPrintable() {
+        assertFalse(StringUtil.isAsciiPrintable(new byte[]{ASCII_DEL}));
+    }
+
+    /**
+     * Verifies that isAsciiPrintable() considers negative bytes to be unprintable.
+     * (In unsigned representation, these are values greater than DEL.)
+     */
+    @Test
+    public void arrayWithNegativeByteIsNotPrintable() {
+        assertFalse(StringUtil.isAsciiPrintable(new byte[]{-128}));
+        assertFalse(StringUtil.isAsciiPrintable(new byte[]{-1}));
+    }
+}