org.apache.shindig.gadgets.parse.AbstractParsingTestBase.java Source code

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Here is the source code for org.apache.shindig.gadgets.parse.AbstractParsingTestBase.java

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/*
 * 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.shindig.gadgets.parse;

import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.io.InputStream;
import java.util.LinkedList;

import name.fraser.neil.plaintext.diff_match_patch;
import name.fraser.neil.plaintext.diff_match_patch.Diff;
import name.fraser.neil.plaintext.diff_match_patch.Operation;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;
import org.w3c.dom.Document;

/**
 * Simple base class providing test helpers for parsing/serializing tests.
 */
public abstract class AbstractParsingTestBase {
    /** The vm line separator */
    private static final String EOL = System.getProperty("line.separator");

    protected String loadFile(String path) throws IOException {
        InputStream is = this.getClass().getClassLoader().getResourceAsStream(path);
        // ENABLE THIS if you have troubles in your IDE loading resources.
        /*if (is == null) {
          is = new FileInputStream(new File("/path/to/your/files/" + path));
        }*/
        return IOUtils.toString(is);
    }

    protected void parseAndCompareBalanced(String content, String expected, GadgetHtmlParser parser)
            throws Exception {
        Document document = parser.parseDom(content);
        expected = expected.replace(EOL, "\n");
        String serialized = HtmlSerialization.serialize(document);
        assertHtmlEquals(expected, serialized);
    }

    private void assertHtmlEquals(String expected, String serialized) {
        // Compute the diff of expected vs. serialized, and disregard constructs that we don't
        // care about, such as whitespace deltas and differently-computed escape sequences.
        diff_match_patch dmp = new diff_match_patch();
        LinkedList<Diff> diffs = dmp.diff_main(expected, serialized);
        while (!diffs.isEmpty()) {
            Diff cur = diffs.removeFirst();
            switch (cur.operation) {
            case DELETE:
                if (StringUtils.isBlank(cur.text) || "amp;".equalsIgnoreCase(cur.text)) {
                    continue;
                }
                if (diffs.isEmpty()) {
                    // End of the set: assert known failure.
                    assertEquals(expected, serialized);
                }
                Diff next = diffs.removeFirst();
                if (next.operation != Operation.INSERT) {
                    // Next operation isn't a paired insert: assert known failure.
                    assertEquals(expected, serialized);
                }
                if (!equivalentEntities(cur.text, next.text) && !cur.text.equalsIgnoreCase(next.text)) {
                    // Delete/insert pair: fail unless each's text is equivalent
                    // either in terms of case or entity equivalence.
                    assertEquals(expected, serialized);
                }
                break;
            case INSERT:
                // Assert known failure unless insert is whitespace/blank.
                if (StringUtils.isBlank(cur.text) || "amp;".equalsIgnoreCase(cur.text)) {
                    continue;
                }
                assertEquals(expected, serialized);
                break;
            default:
                // EQUALS: move on.
                break;
            }
        }
    }

    private boolean equivalentEntities(String prev, String cur) {
        if (!prev.endsWith(";") && !cur.endsWith(";")) {
            return false;
        }
        String prevEnt = StringEscapeUtils.unescapeHtml(prev);
        String curEnt = StringEscapeUtils.unescapeHtml(cur);
        return prevEnt.equals(curEnt);
    }
}