Function findHunkInSource

core/edit/lazy/unifiedDiffApply.ts:136–160

* Searches for an occurrence of the block of lines (the “before” block) in sourceLines, * starting at startIndex. Comparison is done by checking if the lines are exactly equal, * or if their trimmed versions are equal. * * Returns the index in sourceLines where the block begins, or -1 if no matc

(
  sourceLines: string[],
  hunkBeforeLines: string[],
  startIndex: number,
)

 * Returns the index in sourceLines where the block begins, or -1 if no match is found.
 */
function findHunkInSource(
  sourceLines: string[],
  hunkBeforeLines: string[],
  startIndex: number,
): number {
  for (
    let i = startIndex;
    i <= sourceLines.length - hunkBeforeLines.length;
    i++
  ) {
    let match = true;
    for (let j = 0; j < hunkBeforeLines.length; j++) {
      const sl = sourceLines[i + j];
      const hl = hunkBeforeLines[j];
      if (!linesMatch(sl, hl)) {
        match = false;
        break;
      }
    }
    if (match) {
      return i;
    }
  }
  return -1;
}

/**
 * Returns true if the two lines are either exactly equal or equal after trimming whitespace and tabs.