pnpm/patching/config/src/verifyPatches.ts

import { PnpmError } from '@pnpm/error'
import { globalWarn } from '@pnpm/logger'
import { type PatchGroupRecord } from '@pnpm/patching.types'
import { allPatchKeys } from './allPatchKeys.js'

export interface VerifyPatchesOptions {
  patchedDependencies: PatchGroupRecord
  appliedPatches: Set<string>
  allowUnusedPatches: boolean
}

export function verifyPatches ({
  patchedDependencies,
  appliedPatches,
  allowUnusedPatches,
}: VerifyPatchesOptions): void {
  const unusedPatches: string[] = []
  for (const patchKey of allPatchKeys(patchedDependencies)) {
    if (!appliedPatches.has(patchKey)) unusedPatches.push(patchKey)
  }

  if (!unusedPatches.length) return
  const message = `The following patches were not used: ${unusedPatches.join(', ')}`
  if (allowUnusedPatches) {
    globalWarn(message)
    return
  }
  throw new PnpmError('UNUSED_PATCH', message, {
    hint: 'Either remove them from "patchedDependencies" or update them to match packages in your dependencies.',
  })
}