react-diff-viewer-continued/lib/cjs/src/compute-hidden-blocks.js

Continuation of a simple and beautiful text diff viewer component made with diff and React

export function computeHiddenBlocks(lineInformation, diffLines, extraLines) {
    let newBlockIndex = 0;
    let currentBlock;
    const lineBlocks = {};
    const blocks = [];
    lineInformation.forEach((line, lineIndex) => {
        const isDiffLine = diffLines.some((diffLine) => diffLine >= lineIndex - extraLines &&
            diffLine <= lineIndex + extraLines);
        if (!isDiffLine && currentBlock === undefined) {
            // block begins
            currentBlock = {
                index: newBlockIndex,
                startLine: lineIndex,
                endLine: lineIndex,
                lines: 1,
            };
            blocks.push(currentBlock);
            lineBlocks[lineIndex] = currentBlock.index;
            newBlockIndex++;
        }
        else if (!isDiffLine && currentBlock) {
            // block continues
            currentBlock.endLine = lineIndex;
            currentBlock.lines++;
            lineBlocks[lineIndex] = currentBlock.index;
        }
        else {
            // not a block anymore
            currentBlock = undefined;
        }
    });
    return {
        lineBlocks,
        blocks: blocks,
    };
}