main.ts

#!/usr/bin/env -S deno run -A
import { readFile, writeFile, lstat } from "node:fs/promises";
import { $ } from "npm:zx";
import process from "node:process";
import { temporaryDirectory, temporaryWrite } from "npm:tempy";
import { join } from "node:path";
import * as core from "npm:@actions/core";
import { glob } from "npm:glob";

let path = core.getInput("path");
if ((await lstat(path)).isDirectory()) {
  console.log("original path");
  const pattern = join(path, "[Rr][Ee][Aa][Dd][Mm][Ee].{md,mdown,markdown}");
  console.log("glob pattern", pattern);
  const globbed = await glob(pattern);
  console.log("glob result", globbed);
  path = globbed[0];
}
console.log("resolved path", path);

let collection = core.getInput("collection");
if (!collection.includes(":")) {
  collection += ":latest";
}
console.log("resolved collection", collection);

let md = await readFile(path, "utf8");

const tempDirPath = temporaryDirectory();
$.cwd = tempDirPath;

await $`oras pull ${collection}`;
const devcontainerCollection = JSON.parse(
  await readFile(join($.cwd, "devcontainer-collection.json"), "utf8")
);
console.log(devcontainerCollection);

if (devcontainerCollection.features) {
  const featureListMD = devcontainerCollection.features
    .map((f) => {
      let s
      if (f.documentationURL) {
        s = `- **[${f.name || f.id}](${f.documentationURL})**`
      } else {
        s = `- **${f.name || f.id}**`
      }
      if (f.description) {
        s += ` - ${f.description}`
      }
      return s
    })
    .join("\n");
  console.log(featureListMD);

  md = md.replace(
    /(<!-- START_FEATURE_LIST -->)([\s\S]*?)(<!-- END_FEATURE_LIST -->)/,
    `$1\n\n${featureListMD}\n\n$3`
  );
}

if (devcontainerCollection.templates) {
  const templateListMD = devcontainerCollection.templates
    .map((f) => {
      let s
      if (f.documentationURL) {
        s = `- **[${f.name || f.id}](${f.documentationURL})**`
      } else {
        s = `- **${f.name || f.id}**`
      }
      if (f.description) {
        s += ` - ${f.description}`
      }
      return s
    })
    .join("\n");
  console.log(templateListMD);

  md = md.replace(
    /(<!-- START_TEMPLATE_LIST -->)([\s\S]*?)(<!-- END_TEMPLATE_LIST -->)/,
    `$1\n\n${templateListMD}\n\n$3`
  );
}

await writeFile(path, md);