fix(metro-resolver-symlinks): add support for 0.82+ (#3627)

Author: tido64

.changeset/eight-wasps-wonder.md

@@ -0,0 +1,5 @@
+---
+"@rnx-kit/metro-resolver-symlinks": patch
+---
+
+`experimental_retryResolvingFromDisk` should no longer be necessary as of 0.82+

packages/metro-resolver-symlinks/src/utils/enhancedResolveHelpers.ts

@@ -1,6 +1,7 @@
 import { expandPlatformExtensions } from "@rnx-kit/tools-react-native/platform";
 import * as path from "node:path";
 import type { ResolutionContextCompat } from "../types";
+import { isPackageExportsEnabled } from "./metro";
 
 export function getFromDir({
   originModulePath,
@@ -9,16 +10,15 @@ export function getFromDir({
 }
 
 export function makeEnhancedResolveOptions(
-  {
-    extraNodeModules,
-    mainFields,
-    sourceExts,
-    unstable_conditionNames,
-    unstable_enablePackageExports,
-  }: ResolutionContextCompat,
+  context: ResolutionContextCompat,
   platform = "common"
 ) {
+  const { extraNodeModules, mainFields, sourceExts, unstable_conditionNames } =
+    context;
+
   const extensions = sourceExts.map((ext) => `.${ext}`);
+  const enablePackageExports = isPackageExportsEnabled(context);
+
   return {
     // Map Metro's `context.extraNodeModules` to Webpack's `resolve.alias`.
     // Metro's implementation is a subset of Webpack's. See:
@@ -30,13 +30,13 @@ export function makeEnhancedResolveOptions(
     // Add `require` to handle packages that are missing `default`
     // conditional. See
     // https://github.com/webpack/enhanced-resolve/issues/313
-    conditionNames: unstable_enablePackageExports
+    conditionNames: enablePackageExports
       ? unstable_conditionNames.slice()
       : ["require", "node"],
 
     // Unless `unstable_enablePackageExports` is enabled, disable exports
     // map as it currently takes precedence over the `react-native` field.
-    ...(unstable_enablePackageExports ? undefined : { exportsFields: [] }),
+    ...(enablePackageExports ? undefined : { exportsFields: [] }),
 
     extensions:
       platform === "common"

packages/metro-resolver-symlinks/src/utils/metro.ts

@@ -6,7 +6,16 @@ import {
 import * as fs from "node:fs";
 import * as path from "node:path";
 import * as url from "node:url";
-import type { Options } from "../types";
+import type { Options, ResolutionContextCompat } from "../types";
+
+const RETRY_FROM_DISK_FLAG = "experimental_retryResolvingFromDisk";
+
+function disableWithReason(reason: string) {
+  warn(
+    `This version of Metro ${reason}; if you still want to enable it, set it to 'force'.`
+  );
+  return false;
+}
 
 function fileExists(path: string): boolean {
   const stat = fs.statSync(path, { throwIfNoEntry: false });
@@ -20,10 +29,10 @@ function importMetroModule(path: string) {
   } catch (_) {
     throw new Error(
       `Cannot find '${modulePath}'. This probably means that ` +
-        "'experimental_retryResolvingFromDisk' is not compatible with the " +
-        "version of 'metro' that you are currently using. Please update to " +
-        "the latest version and try again. If the issue still persists after " +
-        "the update, please file a bug at " +
+        `'${RETRY_FROM_DISK_FLAG}' is not compatible with the version of ` +
+        "'metro' that you are currently using. Please update to the latest " +
+        "version and try again. If the issue still persists after the " +
+        "update, please file a bug at " +
         "https://github.com/microsoft/rnx-kit/issues."
     );
   }
@@ -41,9 +50,13 @@ const metroVersion = (() => {
   };
 })();
 
-function supportsRetryResolvingFromDisk(): boolean {
-  const v = metroVersion();
-  return v >= 64 && v <= 81;
+export function isPackageExportsEnabled({
+  unstable_enablePackageExports,
+}: Pick<ResolutionContextCompat, "unstable_enablePackageExports">): boolean {
+  // https://github.com/facebook/metro/releases/tag/v0.82.0
+  return unstable_enablePackageExports == null
+    ? metroVersion() >= 82
+    : unstable_enablePackageExports;
 }
 
 export function supportsSymlinks(): boolean {
@@ -53,18 +66,21 @@ export function supportsSymlinks(): boolean {
 
 export function shouldEnableRetryResolvingFromDisk({
   experimental_retryResolvingFromDisk,
-}: Options): boolean {
+}: Pick<Options, typeof RETRY_FROM_DISK_FLAG>): boolean {
   if (
     experimental_retryResolvingFromDisk &&
-    experimental_retryResolvingFromDisk !== "force" &&
-    !supportsRetryResolvingFromDisk()
+    experimental_retryResolvingFromDisk !== "force"
   ) {
-    warn(
-      "The version of Metro you're using has not been tested with " +
-        "`experimental_retryResolvingFromDisk`. If you still want to enable " +
-        "it, please set it to 'force'."
-    );
-    return false;
+    const v = metroVersion();
+    if (v < 64) {
+      return disableWithReason(
+        `has not been tested with '${RETRY_FROM_DISK_FLAG}'`
+      );
+    } else if (v > 81) {
+      return disableWithReason(
+        `should no longer need '${RETRY_FROM_DISK_FLAG}'`
+      );
+    }
   }
 
   return Boolean(experimental_retryResolvingFromDisk);
@@ -102,7 +118,7 @@ export function patchMetro(options: Options): void {
     return;
   }
 
-  info(`experimental_retryResolvingFromDisk: Patching '${findMetroPath()}'`);
+  info(`${RETRY_FROM_DISK_FLAG}: Patching '${findMetroPath()}'`);
 
   const DependencyGraph = importMetroModule("/src/node-haste/DependencyGraph");