netlify-lambda.ts

import { readFile } from 'fs/promises'
import { resolve } from 'path'

import { program } from 'commander'

// @ts-expect-error TS(7034) FIXME: Variable 'execa' implicitly has type 'any' in some... Remove this comment to see the full error message
import execa from '../../../../../utils/execa.js'
import { fileExistsAsync } from '../../../../fs.js'
import { memoizedBuild } from '../../../memoized-build.js'

// @ts-expect-error TS(2525) FIXME: Initializer provides no value for this binding ele... Remove this comment to see the full error message
export const detectNetlifyLambda = async function ({ packageJson } = {}) {
  const { dependencies, devDependencies, scripts } = packageJson || {}
  if (!((dependencies && dependencies['netlify-lambda']) || (devDependencies && devDependencies['netlify-lambda']))) {
    return false
  }

  // @ts-expect-error TS(2571) FIXME: Object is of type 'unknown'.
  const matchingScripts = Object.entries(scripts).filter(([, script]) => script.match(/netlify-lambda\s+build/))

  for (const [key, script] of matchingScripts) {
    // E.g. ["netlify-lambda", "build", "functions/folder"]
    // these are all valid options for netlify-lambda
    program
      .option('-s, --static')
      .option('-c, --config [file]')
      .option('-p, --port [number]')
      .option('-b, --babelrc [file]')
      .option('-t, --timeout [delay]')

    program.parse((script as string).split(' ') ?? [])

    // We are not interested in 'netlify-lambda' and 'build' commands
    const functionDirectories = program.args.filter((arg) => !['netlify-lambda', 'build'].includes(arg))
    if (functionDirectories.length === 1) {
      const srcFiles = [resolve(functionDirectories[0])]

      const yarnExists = await fileExistsAsync('yarn.lock')
      // @ts-expect-error TS(7005) FIXME: Variable 'execa' implicitly has an 'any' type.
      const buildCommand = () => execa(yarnExists ? 'yarn' : 'npm', ['run', key])

      return {
        build: async ({ cache = {} } = {}) => {
          await memoizedBuild({ cache, cacheKey: `netlify-lambda-${key}`, command: buildCommand })

          return {
            srcFiles,
          }
        },
        builderName: 'netlify-lambda',

        // Currently used for tests only.
        npmScript: key,
      }
    }
    if (functionDirectories.length === 0) {
      console.warn(`Command 'netlify-lambda build' was detected in script '${key}', but contained no functions folder`)
    } else {
      console.warn(
        `Command 'netlify-lambda build' was detected in script '${key}', but contained 2 or more function folders`,
      )
    }
  }

  return false
}

export default async function handler() {
  const exists = await fileExistsAsync('package.json')
  if (!exists) {
    return false
  }

  const content = await readFile('package.json', 'utf-8')
  const packageJson = JSON.parse(content)
  return detectNetlifyLambda({ packageJson })
}