smart-git-commit/parseDiff/index.js

AI-powered smart commit message generator for Git diffs.

export default function parseDiff(diff) {
  const fileChanges = [];
  const lines = diff.split("\n");

  let currentFile = null;
  let changeType = null;
  let additions = [];
  let deletions = [];

  for (let line of lines) {
    // Detect New File Block
    if (line.startsWith("diff --git")) {
      if (currentFile) {
        fileChanges.push({
          file: currentFile,
          changeType,
          additions,
          deletions,
        });
      }

      const match = line.match(/a\/(.+?)\s/);
      currentFile = match ? match[1] : "unknown";
      changeType = "modified"; // Default changeType
      additions = [];
      deletions = [];
    }

    // Detect Added File
    if (line.startsWith("new file mode")) {
      changeType = "added";
    }

    // Detect Deleted File
    if (line.startsWith("deleted file mode")) {
      changeType = "deleted";
    }

    // Detect Renamed File (look for "rename from" line)
    if (line.startsWith("rename from")) {
      const renamedFrom = line.split("rename from ")[1];
      currentFile = renamedFrom;
      changeType = "renamed";
    }

    // Added Lines (skip file header lines)
    if (
      line.startsWith("+") &&
      !line.startsWith("+++") &&
      changeType !== "deleted"
    ) {
      additions.push(line.slice(1).trim());
    }

    // Deleted Lines (skip file header lines)
    if (
      line.startsWith("-") &&
      !line.startsWith("---") &&
      changeType !== "added"
    ) {
      deletions.push(line.slice(1).trim());
    }
  }

  // Push last file if exists
  if (currentFile) {
    fileChanges.push({
      file: currentFile,
      changeType,
      additions,
      deletions,
    });
  }

  return fileChanges;
}