org.conqat.lib.commons.diff.LineBasedDiffer Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of teamscale-lib-commons Show documentation
Provides common utility functions
There is a newer version: 2024.7.2
Show newest version
/*
 * Copyright (c) CQSE GmbH
 *
 * 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 org.conqat.lib.commons.diff;

import java.util.ArrayList;
import java.util.List;

import org.conqat.lib.commons.string.StringUtils;

/**
 * Class for calculating a line-based diff.
 */
public class LineBasedDiffer extends DifferBase {

	/** Whether to ignore whitespace in each line. */
	private final boolean ignoreWhitespace;

	/** Whether to annotate test coverage in each line. */
	private final boolean showCoverage;

	/** Constructor. Sets {@link #showCoverage} to false. */
	public LineBasedDiffer(boolean ignoreWhitespace) {
		this(ignoreWhitespace, false);
	}

	/** Constructor. */
	public LineBasedDiffer(boolean ignoreWhitespace, boolean showCoverage) {
		this.ignoreWhitespace = ignoreWhitespace;
		this.showCoverage = showCoverage;
	}

	/** {@inheritDoc} */
	@Override
	protected String getElementText(String element) {
		return element;
	}

	/** {@inheritDoc} */
	@Override
	protected String getDiffName() {
		String diffName = "line-based";
		if (ignoreWhitespace) {
			diffName += " (ignore whitespace)";
		}

		if (showCoverage) {
			diffName += " with coverage";
		}

		return diffName;
	}

	/** {@inheritDoc} */
	@Override
	protected List getChunks(String elementText, boolean isLeft) {
		List lines = StringUtils.splitLinesAsList(elementText);

		List result = new ArrayList<>();
		int offset = 0;
		int lineNumber = 1;
		for (String line : lines) {
			result.add(createChunkForLine(offset, lineNumber, line));
			offset += line.length() + 1;
			lineNumber += 1;
		}
		return result;
	}

	/** Creates a chunk for a single line of the element. */
	private TextChunk createChunkForLine(int offset, int lineNumber, String line) {
		int startOffset = offset;
		int endOffset = startOffset + line.length();
		String comparisonText = line;

		if (ignoreWhitespace) {
			comparisonText = line.replaceFirst("^\\s+", StringUtils.EMPTY_STRING);
			int removed = endOffset - startOffset - comparisonText.length();

			startOffset += removed;

			comparisonText = line.replaceFirst("\\s+$", StringUtils.EMPTY_STRING);
			removed = endOffset - startOffset - comparisonText.length();
			endOffset -= removed;

			comparisonText = comparisonText.replaceAll("\\s+", StringUtils.EMPTY_STRING);
		}

		return new TextChunk(startOffset, endOffset, lineNumber, lineNumber + 1, comparisonText);
	}
}