keep supporting legacy externals

src/rollup/config.ts

@@ -25,6 +25,7 @@ import { replace } from "./plugins/replace";
 import { virtual } from "./plugins/virtual";
 import { dynamicRequire } from "./plugins/dynamic-require";
 import { externals } from "./plugins/externals";
+import { externals as legacyExternals } from "./plugins/externals-legacy";
 import { timing } from "./plugins/timing";
 import { publicAssets } from "./plugins/public-assets";
 import { serverAssets } from "./plugins/server-assets";
@@ -305,8 +306,11 @@ export const plugins = [
 
   // Externals Plugin
   if (!nitro.options.noExternals) {
+    let externalsPlugin = nitro.options.experimental.legacyExternals
+      ? legacyExternals
+      : externals;
     rollupConfig.plugins.push(
-      externals(
+      externalsPlugin(
         defu(nitro.options.externals, {
           outDir: nitro.options.output.serverDir,
           moduleDirectories: nitro.options.nodeModulesDirs,

src/rollup/plugins/externals-legacy.ts

@@ -0,0 +1,338 @@
+import { existsSync, promises as fsp } from "node:fs";
+import { resolve, dirname, normalize, join, isAbsolute } from "pathe";
+import consola from "consola";
+import { nodeFileTrace, NodeFileTraceOptions } from "@vercel/nft";
+import type { Plugin } from "rollup";
+import { resolvePath, isValidNodeImport, normalizeid } from "mlly";
+import semver from "semver";
+import { isDirectory, retry } from "../../utils";
+
+export interface NodeExternalsOptions {
+  inline?: string[];
+  external?: string[];
+  outDir?: string;
+  trace?: boolean;
+  traceOptions?: NodeFileTraceOptions;
+  moduleDirectories?: string[];
+  exportConditions?: string[];
+  traceInclude?: string[];
+}
+
+export function externals(opts: NodeExternalsOptions): Plugin {
+  const trackedExternals = new Set<string>();
+
+  const _resolveCache = new Map();
+  const _resolve = async (id: string) => {
+    let resolved = _resolveCache.get(id);
+    if (resolved) {
+      return resolved;
+    }
+    resolved = await resolvePath(id, {
+      conditions: opts.exportConditions,
+      url: opts.moduleDirectories,
+    });
+    _resolveCache.set(id, resolved);
+    return resolved;
+  };
+
+  // Normalize options
+  opts.inline = (opts.inline || []).map((p) => normalize(p));
+  opts.external = (opts.external || []).map((p) => normalize(p));
+
+  return {
+    name: "node-externals",
+    async resolveId(originalId, importer, options) {
+      // Skip internals
+      if (
+        !originalId ||
+        originalId.startsWith("\u0000") ||
+        originalId.includes("?") ||
+        originalId.startsWith("#")
+      ) {
+        return null;
+      }
+
+      // Skip relative paths
+      if (originalId.startsWith(".")) {
+        return null;
+      }
+
+      // Normalize path (windows)
+      const id = normalize(originalId);
+
+      // Id without .../node_modules/
+      const idWithoutNodeModules = id.split("node_modules/").pop();
+
+      // Check for explicit inlines
+      if (
+        opts.inline.some(
+          (i) => id.startsWith(i) || idWithoutNodeModules.startsWith(i)
+        )
+      ) {
+        return null;
+      }
+
+      // Check for explicit externals
+      if (
+        opts.external.some(
+          (i) => id.startsWith(i) || idWithoutNodeModules.startsWith(i)
+        )
+      ) {
+        return { id, external: true };
+      }
+
+      // Resolve id using rollup resolver
+      const resolved = (await this.resolve(originalId, importer, {
+        ...options,
+        skipSelf: true,
+      })) || { id };
+
+      // Try resolving with mlly as fallback
+      if (
+        !isAbsolute(resolved.id) ||
+        !existsSync(resolved.id) ||
+        (await isDirectory(resolved.id))
+      ) {
+        resolved.id = await _resolve(resolved.id).catch(() => resolved.id);
+      }
+
+      // Inline invalid node imports
+      if (!(await isValidNodeImport(resolved.id).catch(() => false))) {
+        return null;
+      }
+
+      // Externalize with full path if trace is disabled
+      if (opts.trace === false) {
+        return {
+          ...resolved,
+          id: isAbsolute(resolved.id) ? normalizeid(resolved.id) : resolved.id,
+          external: true,
+        };
+      }
+
+      // -- Trace externals --
+
+      // Try to extract package name from path
+      const { pkgName, subpath } = parseNodeModulePath(resolved.id);
+
+      // Inline if cannot detect package name
+      if (!pkgName) {
+        return null;
+      }
+
+      // Normally package name should be same as originalId
+      // Edge cases: Subpath export and full paths
+      if (pkgName !== originalId) {
+        // Subpath export
+        if (!isAbsolute(originalId)) {
+          const fullPath = await _resolve(originalId);
+          trackedExternals.add(fullPath);
+          return {
+            id: originalId,
+            external: true,
+          };
+        }
+
+        // Absolute path, we are not sure about subpath to generate import statement
+        // Guess as main subpath export
+        const packageEntry = await _resolve(pkgName).catch(() => null);
+        if (packageEntry !== originalId) {
+          // Guess subpathexport
+          const guessedSubpath = pkgName + subpath.replace(/\.[a-z]+$/, "");
+          const resolvedGuess = await _resolve(guessedSubpath).catch(
+            () => null
+          );
+          if (resolvedGuess === originalId) {
+            trackedExternals.add(resolvedGuess);
+            return {
+              id: guessedSubpath,
+              external: true,
+            };
+          }
+          // Inline since we cannot guess subpath
+          return null;
+        }
+      }
+
+      trackedExternals.add(resolved.id);
+      return {
+        id: pkgName,
+        external: true,
+      };
+    },
+    async buildEnd() {
+      if (opts.trace === false) {
+        return;
+      }
+
+      // Force trace paths
+      for (const pkgName of opts.traceInclude || []) {
+        const path = await this.resolve(pkgName);
+        if (path?.id) {
+          trackedExternals.add(path.id.replace(/\?.+/, ""));
+        }
+      }
+
+      // Trace files
+      let tracedFiles = await nodeFileTrace(
+        [...trackedExternals],
+        opts.traceOptions
+      )
+        .then((r) =>
+          [...r.fileList].map((f) => resolve(opts.traceOptions.base, f))
+        )
+        .then((r) => r.filter((file) => file.includes("node_modules")));
+
+      // Resolve symlinks
+      tracedFiles = await Promise.all(
+        tracedFiles.map((file) => fsp.realpath(file))
+      );
+
+      // Read package.json with cache
+      const packageJSONCache = new Map(); // pkgDir => contents
+      const getPackageJson = async (pkgDir: string) => {
+        if (packageJSONCache.has(pkgDir)) {
+          return packageJSONCache.get(pkgDir);
+        }
+        const pkgJSON = JSON.parse(
+          await fsp.readFile(resolve(pkgDir, "package.json"), "utf8")
+        );
+        packageJSONCache.set(pkgDir, pkgJSON);
+        return pkgJSON;
+      };
+
+      // Keep track of npm packages
+      const tracedPackages = new Map(); // name => pkgDir
+      const ignoreDirs = [];
+      const ignoreWarns = new Set();
+      for (const file of tracedFiles) {
+        const { baseDir, pkgName } = parseNodeModulePath(file);
+        if (!pkgName) {
+          continue;
+        }
+        let pkgDir = resolve(baseDir, pkgName);
+
+        // Check for duplicate versions
+        const existingPkgDir = tracedPackages.get(pkgName);
+        if (existingPkgDir && existingPkgDir !== pkgDir) {
+          const v1 = await getPackageJson(existingPkgDir).then(
+            (r) => r.version
+          );
+          const v2 = await getPackageJson(pkgDir).then((r) => r.version);
+          const isNewer = semver.gt(v2, v1);
+
+          // Warn about major version differences
+          const getMajor = (v: string) => v.split(".").find((s) => s !== "0");
+          if (getMajor(v1) !== getMajor(v2)) {
+            const warn =
+              `Multiple major versions of package \`${pkgName}\` are being externalized. Picking latest version:\n\n` +
+              [
+                `  ${isNewer ? "-" : "+"} ` + existingPkgDir + "@" + v1,
+                `  ${isNewer ? "+" : "-"} ` + pkgDir + "@" + v2,
+              ].join("\n");
+            if (!ignoreWarns.has(warn)) {
+              consola.warn(warn);
+              ignoreWarns.add(warn);
+            }
+          }
+
+          const [newerDir, olderDir] = isNewer
+            ? [pkgDir, existingPkgDir]
+            : [existingPkgDir, pkgDir];
+          // Try to map traced files from one package to another for minor/patch versions
+          if (getMajor(v1) === getMajor(v2)) {
+            tracedFiles = tracedFiles.map((f) =>
+              f.startsWith(olderDir + "/") ? f.replace(olderDir, newerDir) : f
+            );
+          }
+          // Exclude older version files
+          ignoreDirs.push(olderDir + "/");
+          pkgDir = newerDir; // Update for tracedPackages
+        }
+
+        // Add to traced packages
+        tracedPackages.set(pkgName, pkgDir);
+      }
+
+      // Filter out files from ignored packages and dedup
+      tracedFiles = tracedFiles.filter(
+        (f) => !ignoreDirs.some((d) => f.startsWith(d))
+      );
+      tracedFiles = [...new Set(tracedFiles)];
+
+      // Ensure all package.json files are traced
+      for (const pkgDir of tracedPackages.values()) {
+        const pkgJSON = join(pkgDir, "package.json");
+        if (!tracedFiles.includes(pkgJSON)) {
+          tracedFiles.push(pkgJSON);
+        }
+      }
+
+      const writeFile = async (file: string) => {
+        if (!(await isFile(file))) {
+          return;
+        }
+        const src = resolve(opts.traceOptions.base, file);
+        const { pkgName, subpath } = parseNodeModulePath(file);
+        const dst = resolve(opts.outDir, `node_modules/${pkgName + subpath}`);
+        await fsp.mkdir(dirname(dst), { recursive: true });
+        try {
+          await fsp.copyFile(src, dst);
+        } catch {
+          consola.warn(`Could not resolve \`${src}\`. Skipping.`);
+        }
+      };
+
+      // Write traced files
+      await Promise.all(
+        tracedFiles.map((file) => retry(() => writeFile(file), 3))
+      );
+
+      // Write an informative package.json
+      await fsp.writeFile(
+        resolve(opts.outDir, "package.json"),
+        JSON.stringify(
+          {
+            name: "nitro-output",
+            version: "0.0.0",
+            private: true,
+            bundledDependencies: [...tracedPackages.keys()],
+          },
+          null,
+          2
+        ),
+        "utf8"
+      );
+    },
+  };
+}
+
+function parseNodeModulePath(path: string) {
+  if (!path) {
+    return {};
+  }
+  const match = /^(.+\/node_modules\/)([^/@]+|@[^/]+\/[^/]+)(\/?.*?)?$/.exec(
+    normalize(path)
+  );
+  if (!match) {
+    return {};
+  }
+  const [, baseDir, pkgName, subpath] = match;
+  return {
+    baseDir,
+    pkgName,
+    subpath,
+  };
+}
+
+async function isFile(file: string) {
+  try {
+    const stat = await fsp.stat(file);
+    return stat.isFile();
+  } catch (err) {
+    if (err.code === "ENOENT") {
+      return false;
+    }
+    throw err;
+  }
+}

src/types/nitro.ts

@@ -174,6 +174,7 @@ export interface NitroOptions extends PresetOptions {
   noPublicDir: boolean;
   experimental?: {
     wasm?: boolean | RollupWasmOptions;
+    legacyExternals?: boolean;
   };
   serverAssets: ServerAssetDir[];
   publicAssets: PublicAssetDir[];