pnpm/packages/lockfile-file/src/gitMergeFile.ts

import { Lockfile } from '@pnpm/lockfile-types'
import mergeLockfilesChanges from '@pnpm/merge-lockfile-changes'
import yaml = require('js-yaml')

const MERGE_CONFLICT_PARENT = '|||||||'
const MERGE_CONFLICT_END = '>>>>>>>'
const MERGE_CONFLICT_THEIRS = '======='
const MERGE_CONFLICT_OURS = '<<<<<<<'

export function autofixMergeConflicts (fileContent: string) {
  const { ours, theirs } = parseMergeFile(fileContent)
  const oursParsed = yaml.safeLoad(ours) as Lockfile
  return mergeLockfilesChanges({
    base: oursParsed,
    ours: oursParsed,
    theirs: yaml.safeLoad(theirs) as Lockfile,
  })
}

function parseMergeFile (fileContent: string) {
  const lines = fileContent.split(/[\n\r]+/g) as string[]
  let state: 'top' | 'ours' | 'theirs' | 'parent' = 'top'
  const ours = []
  const theirs = []
  const base = []
  while (lines.length > 0) {
    const line = lines.shift() as string
    if (line.startsWith(MERGE_CONFLICT_PARENT)) {
      state = 'parent'
      continue
    }
    if (line.startsWith(MERGE_CONFLICT_OURS)) {
      state = 'ours'
      continue
    }
    if (line === MERGE_CONFLICT_THEIRS) {
      state = 'theirs'
      continue
    }
    if (line.startsWith(MERGE_CONFLICT_END)) {
      state = 'top'
      continue
    }
    if (state === 'top' || state === 'ours') ours.push(line)
    if (state === 'top' || state === 'theirs') theirs.push(line)
    if (state === 'top' || state === 'parent') base.push(line)
  }
  return { ours: ours.join('\n'), theirs: theirs.join('\n'), base: base.join('\n') }
}

export function isDiff (fileContent: string) {
  return fileContent.includes(MERGE_CONFLICT_OURS) &&
    fileContent.includes(MERGE_CONFLICT_THEIRS) &&
    fileContent.includes(MERGE_CONFLICT_END)
}