index.js

const core     = require('@actions/core')
const glob     = require('@actions/glob')
const renderer = require('./renderer')
const path     = require('path')
const fs       = require('fs').promises



// most @actions toolkit packages have async methods
async function run() {
  try {
    const input     = core.getInput('input', {required: true})
    const output    = core.getInput('output')
    const hard_fail = core.getInput('hard-fail').toLowerCase() === 'true'
    const log       = core.getInput('enable-log').toLowerCase() === 'true'
    const symlinks  = core.getInput('follow-symbolic-links').toLowerCase() === 'true'

    core.debug(`input:     ${input}`)
    core.debug(`output:    ${output}`)
    core.debug(`hard_fail: ${hard_fail}`)
    core.debug(`log:       ${log}`)
    core.debug(`symlinks:  ${symlinks}`)

    if(output)
      await fs.mkdir(output, {recursive: true})

    const globber = await glob.create(input, { followSymbolicLinks: symlinks })
    for await (const file of globber.globGenerator()) {
      let stat = await fs.stat(file)
      if(!stat.isFile())
        continue

      let handle = await fs.open(file, 'r+')
      
      const data = await handle.readFile('utf8')

      
      

      const rendered = renderer.render(data, /\$\{([A-Z_-]+)\}/gm, hard_fail)

      if(log) {
        core.debug(`===== ORIGINAL: ${file}`)
        core.debug(data)
        core.debug("===== PROCESSED: ")
        core.debug(rendered)
      }

      if(output) {
        await handle.close();

        const basename = path.basename(file)
        const outputName = path.join(output, basename)
        handle = await fs.open(outputName, 'w+')
      }

      let tmp = await handle.write(rendered, 0)
      await handle.truncate(tmp.bytesWritten)
      await handle.close();
    }
    
  } catch (error) {
    core.setFailed(error.message);
  }
}

run();