fixup: change async/thenable detection

lib/internal/modules/esm/loader.js

@@ -15,6 +15,8 @@ const {
   ObjectDefineProperty,
   ObjectSetPrototypeOf,
   PromiseAll,
+  PromiseResolve,
+  PromisePrototypeThen,
   ReflectApply,
   RegExpPrototypeExec,
   SafeArrayIterator,
@@ -109,12 +111,14 @@ let emittedSpecifierResolutionWarning = false;
  * position in the hook chain.
  * @param {string} meta.hookName The kind of hook the chain is (ex 'resolve')
  * @param {boolean} meta.shortCircuited Whether a hook signaled a short-circuit.
- * @param {(hookErrIdentifier, hookArgs) => void} validate A wrapper function
+ * @param {object} validators A wrapper function
  *  containing all validation of a custom loader hook's intermediary output. Any
  *  validation within MUST throw.
+ * @param {(hookErrIdentifier, hookArgs) => void} validateArgs
+ * @param {(hookErrIdentifier, output) => void} validateOutput
  * @returns {function next<HookName>(...hookArgs)} The next hook in the chain.
  */
-function nextHookFactory(chain, meta, validate) {
+function nextHookFactory(chain, meta, { validateArgs, validateOutput }) {
   // First, prepare the current
   const { hookName } = meta;
   const {
@@ -137,7 +141,7 @@ function nextHookFactory(chain, meta, validate) {
     // factory generates the next link in the chain.
     meta.hookIndex--;
 
-    nextNextHook = nextHookFactory(chain, meta, validate);
+    nextNextHook = nextHookFactory(chain, meta, { validateArgs, validateOutput });
   } else {
     // eslint-disable-next-line func-name-matching
     nextNextHook = function chainAdvancedTooFar() {
@@ -152,34 +156,25 @@ function nextHookFactory(chain, meta, validate) {
       // Update only when hook is invoked to avoid fingering the wrong filePath
       meta.hookErrIdentifier = `${hookFilePath} '${hookName}'`;
 
-      validate(`${meta.hookErrIdentifier} hook's ${nextHookName}()`, args);
+      validateArgs(`${meta.hookErrIdentifier} hook's ${nextHookName}()`, args);
+
+      const outputErrIdentifier = `${chain[generatedHookIndex].url} '${hookName}' hook's ${nextHookName}()`;
 
       // Set when next<HookName> is actually called, not just generated.
       if (generatedHookIndex === 0) { meta.chainFinished = true; }
 
       ArrayPrototypePush(args, nextNextHook);
-      const output = ReflectApply(hook, undefined, args);
+      let output = ReflectApply(hook, undefined, args);
+
+      validateOutput(outputErrIdentifier, output);
 
       function checkShortCircuited(output) {
         if (output?.shortCircuit === true) { meta.shortCircuited = true; }
       }
 
-      const then = output?.then;
-      if (typeof then === 'function') {
-        if (!meta.isChainAsync) {
-          throw ERR_INVALID_RETURN_VALUE(
-            'an object',
-            // MUST use generatedHookIndex because the chain has already advanced,
-            // causing meta.hookIndex to advance
-            `${chain[generatedHookIndex].url} '${hookName}' hook's ${nextHookName}()`,
-            output,
-          );
-        }
-
-        ReflectApply(then, output, [
-          checkShortCircuited,
-          // TODO: handle error case
-        ]);
+      if (meta.isChainAsync) {
+        output = PromiseResolve(output);
+        PromisePrototypeThen(output, checkShortCircuited);
       } else {
         checkShortCircuited(output);
       }
@@ -586,7 +581,7 @@ class ESMLoader {
       shortCircuited: false,
     };
 
-    const validate = (hookErrIdentifier, { 0: nextUrl, 1: ctx }) => {
+    const validateArgs = (hookErrIdentifier, { 0: nextUrl, 1: ctx }) => {
       if (typeof nextUrl !== 'string') {
         // non-strings can be coerced to a url string
         // validateString() throws a less-specific error
@@ -612,19 +607,22 @@ class ESMLoader {
 
       validateObject(ctx, `${hookErrIdentifier} context`);
     };
+    const validateOutput = (hookErrIdentifier, output) => {
+      if (typeof output !== 'object') { // [2]
+        throw new ERR_INVALID_RETURN_VALUE(
+          'an object',
+          hookErrIdentifier,
+          output,
+        );
+      }
+    };
 
-    const nextLoad = nextHookFactory(chain, meta, validate);
+    const nextLoad = nextHookFactory(chain, meta, { validateArgs, validateOutput });
 
     const loaded = await nextLoad(url, context);
     const { hookErrIdentifier } = meta; // Retrieve the value after all settled
 
-    if (typeof loaded !== 'object') { // [2]
-      throw new ERR_INVALID_RETURN_VALUE(
-        'an object',
-        hookErrIdentifier,
-        loaded,
-      );
-    }
+    validateOutput(hookErrIdentifier, loaded);
 
     if (loaded?.shortCircuit === true) { meta.shortCircuited = true; }
 
@@ -837,7 +835,7 @@ class ESMLoader {
       parentURL,
     };
 
-    const validate = (hookErrIdentifier, output) => {
+    const validateArgs = (hookErrIdentifier, output) => {
       const { 0: suppliedSpecifier, 1: ctx } = output;
 
       validateString(
@@ -847,22 +845,25 @@ class ESMLoader {
 
       validateObject(ctx, `${hookErrIdentifier} context`);
     };
+    const validateOutput = (hookErrIdentifier, output) => {
+      if (
+        typeof output !== 'object' || // [2]
+        typeof output.then === 'function'
+      ) {
+        throw new ERR_INVALID_RETURN_VALUE(
+          'an object',
+          hookErrIdentifier,
+          output,
+        );
+      }
+    };
 
-    const nextResolve = nextHookFactory(chain, meta, validate);
+    const nextResolve = nextHookFactory(chain, meta, { validateArgs, validateOutput });
 
     const resolution = nextResolve(originalSpecifier, context);
     const { hookErrIdentifier } = meta; // Retrieve the value after all settled
 
-    if (
-      typeof resolution !== 'object' || // [2]
-      typeof resolution?.then === 'function'
-    ) {
-      throw new ERR_INVALID_RETURN_VALUE(
-        'an object',
-        hookErrIdentifier,
-        resolution,
-      );
-    }
+    validateOutput(hookErrIdentifier, resolution);
 
     if (resolution?.shortCircuit === true) { meta.shortCircuited = true; }