Forgot tests for PDF417 EC

git-svn-id: https://zxing.googlecode.com/svn/trunk@2278 59b500cc-1b3d-0410-9834-0bbf25fbcc57

core/test/src/com/google/zxing/pdf417/decoder/ec/AbstractErrorCorrectionTestCase.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012 ZXing authors
+ *
+ * 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.google.zxing.pdf417.decoder.ec;
+
+import org.junit.Assert;
+
+import java.security.SecureRandom;
+import java.util.BitSet;
+import java.util.Random;
+
+/**
+ * @author Sean Owen
+ */
+abstract class AbstractErrorCorrectionTestCase extends Assert {
+
+  static void corrupt(int[] received, int howMany, Random random) {
+    BitSet corrupted = new BitSet(received.length);
+    for (int j = 0; j < howMany; j++) {
+      int location = random.nextInt(received.length);
+      if (corrupted.get(location)) {
+        j--;
+      } else {
+        corrupted.set(location);
+        received[location] = random.nextInt(929);
+      }
+    }
+  }
+
+  static Random getRandom() {
+    return new SecureRandom(new byte[] {(byte) 0xDE, (byte) 0xAD, (byte) 0xBE, (byte) 0xEF});
+  }
+
+  static void assertArraysEqual(int[] expected,
+                                int expectedOffset,
+                                int[] actual,
+                                int actualOffset,
+                                int length) {
+    for (int i = 0; i < length; i++) {
+      assertEquals(expected[expectedOffset + i], actual[actualOffset + i]);
+    }
+  }
+
+}

core/test/src/com/google/zxing/pdf417/decoder/ec/ErrorCorrectionTestCase.java

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+/*
+ * Copyright 2012 ZXing authors
+ *
+ * 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.google.zxing.pdf417.decoder.ec;
+
+import com.google.zxing.ChecksumException;
+import org.junit.Test;
+
+import java.util.Random;
+
+/**
+ * @author Sean Owen
+ */
+public final class ErrorCorrectionTestCase extends AbstractErrorCorrectionTestCase {
+
+  /** See ISO 15438, Annex Q */
+  private static final int[] PDF417_TEST =
+      { 5, 453, 178, 121, 239 };
+  private static final int[] PDF417_TEST_WITH_EC =
+      { 5, 453, 178, 121, 239, 452, 327, 657, 619 };
+  private static final int ECC_BYTES = PDF417_TEST_WITH_EC.length - PDF417_TEST.length;
+  private static final int CORRECTABLE = ECC_BYTES / 2;
+
+  private final ErrorCorrection ec = new ErrorCorrection();
+
+  @Test
+  public void testNoError() throws ChecksumException {
+    int[] received = PDF417_TEST_WITH_EC.clone();
+    // no errors
+    checkDecode(received);
+  }
+
+  @Test
+  public void testOneError() throws ChecksumException {
+    Random random = getRandom();
+    for (int i = 0; i < PDF417_TEST_WITH_EC.length; i++) {
+      int[] received = PDF417_TEST_WITH_EC.clone();
+      received[i] = random.nextInt(256);
+      checkDecode(received);
+    }
+  }
+
+  @Test
+  public void testMaxErrors() throws ChecksumException {
+    Random random = getRandom();
+    for (int test : PDF417_TEST) { // # iterations is kind of arbitrary
+      int[] received = PDF417_TEST_WITH_EC.clone();
+      corrupt(received, CORRECTABLE, random);
+      checkDecode(received);
+    }
+  }
+
+  @Test
+  public void testTooManyErrors() {
+    int[] received = PDF417_TEST_WITH_EC.clone();
+    Random random = getRandom();
+    corrupt(received, CORRECTABLE + 1, random);
+    try {
+      checkDecode(received);
+      fail("Should not have decoded");
+    } catch (ChecksumException ce) {
+      // good
+    }
+  }
+
+  private void checkDecode(int[] received) throws ChecksumException {
+    ec.decode(received, ECC_BYTES);
+    for (int i = 0; i < PDF417_TEST.length; i++) {
+      assertEquals(received[i], PDF417_TEST[i]);
+    }
+  }
+
+}