src/utils/file.js
function exists(repoState, filepath) {
    const workingState = repoState.getCurrentState();
    const mergedFileSet = WorkingUtils.getMergedTreeEntries(workingState);

    return mergedFileSet.has(filepath);
}
function exists(repoState, filepath) {
    const workingState = repoState.getCurrentState();
    const mergedFileSet = WorkingUtils.getMergedTreeEntries(workingState);

    return mergedFileSet.has(filepath);
}
Return true if file exists in working tree, false otherwise