astro/dist/core/server-islands/vite-plugin-server-islands.js

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

import MagicString from "magic-string";
const VIRTUAL_ISLAND_MAP_ID = "@astro-server-islands";
const RESOLVED_VIRTUAL_ISLAND_MAP_ID = "\0" + VIRTUAL_ISLAND_MAP_ID;
const serverIslandPlaceholder = "'$$server-islands$$'";
function vitePluginServerIslands({ settings, logger }) {
  let command = "serve";
  let viteServer = null;
  const referenceIdMap = /* @__PURE__ */ new Map();
  return {
    name: "astro:server-islands",
    enforce: "post",
    config(_config, { command: _command }) {
      command = _command;
    },
    configureServer(_server) {
      viteServer = _server;
    },
    resolveId(name) {
      if (name === VIRTUAL_ISLAND_MAP_ID) {
        return RESOLVED_VIRTUAL_ISLAND_MAP_ID;
      }
    },
    load(id) {
      if (id === RESOLVED_VIRTUAL_ISLAND_MAP_ID) {
        return { code: `export const serverIslandMap = ${serverIslandPlaceholder};` };
      }
    },
    transform(_code, id) {
      if (id.endsWith(".astro")) {
        const info = this.getModuleInfo(id);
        if (info?.meta) {
          const astro = info.meta.astro;
          if (astro?.serverComponents.length) {
            for (const comp of astro.serverComponents) {
              if (!settings.serverIslandNameMap.has(comp.resolvedPath)) {
                if (!settings.adapter) {
                  logger.error(
                    "islands",
                    "You tried to render a server island without an adapter added to your project. An adapter is required to use the `server:defer` attribute on any component. Your project will fail to build unless you add an adapter or remove the attribute."
                  );
                }
                let name = comp.localName;
                let idx = 1;
                while (true) {
                  if (!settings.serverIslandMap.has(name)) {
                    break;
                  }
                  name += idx++;
                }
                settings.serverIslandNameMap.set(comp.resolvedPath, name);
                settings.serverIslandMap.set(name, () => {
                  return viteServer?.ssrLoadModule(comp.resolvedPath);
                });
                if (command === "build") {
                  let referenceId = this.emitFile({
                    type: "chunk",
                    id: comp.specifier,
                    importer: id,
                    name: comp.localName
                  });
                  referenceIdMap.set(comp.resolvedPath, referenceId);
                }
              }
            }
          }
        }
      }
    },
    renderChunk(code) {
      if (code.includes(serverIslandPlaceholder)) {
        if (referenceIdMap.size === 0) {
          return {
            code: code.replace(serverIslandPlaceholder, "new Map();"),
            map: null
          };
        }
        let mapSource = "new Map([";
        for (let [resolvedPath, referenceId] of referenceIdMap) {
          const fileName = this.getFileName(referenceId);
          const islandName = settings.serverIslandNameMap.get(resolvedPath);
          mapSource += `
	['${islandName}', () => import('./${fileName}')],`;
        }
        mapSource += "\n]);";
        referenceIdMap.clear();
        const ms = new MagicString(code);
        ms.replace(serverIslandPlaceholder, mapSource);
        return {
          code: ms.toString(),
          map: ms.generateMap({ hires: "boundary" })
        };
      }
    }
  };
}
export {
  VIRTUAL_ISLAND_MAP_ID,
  vitePluginServerIslands
};