astro/dist/vite-plugin-astro/hmr.js

Astro is a modern site builder with web best practices, performance, and DX front-of-mind.

import { frontmatterRE } from "./utils.js";
async function handleHotUpdate(ctx, { logger, astroFileToCompileMetadata }) {
  for (const [astroFile, compileData] of astroFileToCompileMetadata) {
    const isUpdatedFileCssDep = compileData.css.some((css) => css.dependencies?.includes(ctx.file));
    if (isUpdatedFileCssDep) {
      astroFileToCompileMetadata.delete(astroFile);
    }
  }
  const oldCode = astroFileToCompileMetadata.get(ctx.file)?.originalCode;
  if (oldCode == null) return;
  const newCode = await ctx.read();
  if (isStyleOnlyChanged(oldCode, newCode)) {
    logger.debug("watch", "style-only change");
    astroFileToCompileMetadata.delete(ctx.file);
    return ctx.modules.filter((mod) => mod.id?.includes("astro&type=style"));
  }
}
const scriptRE = /<script(?:\s.*?)?>.*?<\/script>/gs;
const styleRE = /<style(?:\s.*?)?>.*?<\/style>/gs;
function isStyleOnlyChanged(oldCode, newCode) {
  if (oldCode === newCode) return false;
  let oldFrontmatter = "";
  let newFrontmatter = "";
  oldCode = oldCode.replace(frontmatterRE, (m) => (oldFrontmatter = m, ""));
  newCode = newCode.replace(frontmatterRE, (m) => (newFrontmatter = m, ""));
  if (oldFrontmatter !== newFrontmatter) return false;
  const oldScripts = [];
  const newScripts = [];
  oldCode = oldCode.replace(scriptRE, (m) => (oldScripts.push(m), ""));
  newCode = newCode.replace(scriptRE, (m) => (newScripts.push(m), ""));
  if (!isArrayEqual(oldScripts, newScripts)) return false;
  const oldStyles = [];
  const newStyles = [];
  oldCode = oldCode.replace(styleRE, (m) => (oldStyles.push(m), ""));
  newCode = newCode.replace(styleRE, (m) => (newStyles.push(m), ""));
  if (oldCode !== newCode) return false;
  return oldStyles.length === newStyles.length && !isArrayEqual(oldStyles, newStyles);
}
function isArrayEqual(a, b) {
  if (a.length !== b.length) {
    return false;
  }
  for (let i = 0; i < a.length; i++) {
    if (a[i] !== b[i]) {
      return false;
    }
  }
  return true;
}
export {
  handleHotUpdate,
  isStyleOnlyChanged
};