module: support require()ing synchronous ESM graphs

This patch adds `require()` support for synchronous ESM graphs under
the flag --experimental-require-module.

This is based on the the following design aspect of ESM:

- The resolution can be synchronous (up to the host)
- The evaluation of a synchronous graph (without top-level await)
  is also synchronous, and, by the time the module graph is
  instantiated (before evaluation starts), this is is already known.

When --experimental-require-module is enabled, and require() resolves
to an ES module, if the module is fully synchronous (contains no
top-level await), the `require()` call returns the module name space
object. Otherwise, Node.js throws an error without executing the module.
If `--print-required-tla` is passed, Node.js will evaluate the module,
try to locate the top-level awaits, and print their location to help
users fix them.

With this option alone, the module being `require()`'d should be explicitly
marked as an ES module either using the `"type": "module"` field in
`package.json` or the `.mjs` extension. To load implicit ES modules ending
with `.js` using automatic syntax-based module type detection, use
`--experimental-require-module-with-detection`.

.eslintignore

@@ -13,3 +13,5 @@ doc/changelogs/CHANGELOG_v1*.md
 !doc/changelogs/CHANGELOG_v18.md
 !doc/api_assets/*.js
 !.eslintrc.js
+test/es-module/test-require-module-detect-entry-point.js
+test/es-module/test-require-module-detect-entry-point-aou.js

doc/api/cli.md

@@ -871,6 +871,39 @@ added: v11.8.0
 
 Use the specified file as a security policy.
 
+### `--experimental-require-module`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1.1 - Active Developement
+
+Supports loading a synchronous ES module graph in `require()`. If the module
+graph is not synchronous (contains top-level await), Node.js throws an error
+without executing the module. If `--print-pending-tla` is passed, Node.js
+will evaluate the module, try to locate the top-level awaits, and print
+their location to help users fix them.
+
+With this option alone, the module being `require()`'d should be explicitly
+marked as an ES module either using the `"type": "module"` field in
+`package.json` or the `.mjs` extension. To load implicit ES modules with
+automatic syntax-based module type detection, use
+`--experimental-require-module-with-detection`.
+
+### `--experimental-require-module-with-detection`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1.1 - Active Developement
+
+In addition to what `--experimental-require-module` supports, when the module
+being `require()`'d is not explicitly marked as an ES Module using the
+`"type": "module"` field in `package.json` or the `.mjs` extension, it will
+try to detect module type based on the syntax of the module.
+
 ### `--experimental-sea-config`
 
 <!-- YAML
@@ -2523,6 +2556,8 @@ Node.js options that are allowed are:
 * `--experimental-network-imports`
 * `--experimental-permission`
 * `--experimental-policy`
+* `--experimental-require-module-with-detection`
+* `--experimental-require-module`
 * `--experimental-shadow-realm`
 * `--experimental-specifier-resolution`
 * `--experimental-top-level-await`

doc/api/errors.md

@@ -2487,13 +2487,27 @@ Accessing `Object.prototype.__proto__` has been forbidden using
 [`Object.setPrototypeOf`][] should be used to get and set the prototype of an
 object.
 
+<a id="ERR_REQUIRE_ASYNC_MODULE"></a>
+
+### `ERR_REQUIRE_ASYNC_MODULE`
+
+> Stability: 1 - Experimental
+
+When trying to `require()` a [ES Module][] under `--experimental-require-module`,
+the module turns out to be asynchronous. That is, it contains top-level await.
+To see where the top-level await is, use
+`--print-pending-tla` (this would execute the modules before looking for
+the top-level awaits).
+
 <a id="ERR_REQUIRE_ESM"></a>
 
 ### `ERR_REQUIRE_ESM`
 
 > Stability: 1 - Experimental
 
-An attempt was made to `require()` an [ES Module][].
+An attempt was made to `require()` an [ES Module][]. To enable `require()` for
+synchronous module graphs (without top-level await), use
+`--experimental-require-module`.
 
 <a id="ERR_SCRIPT_EXECUTION_INTERRUPTED"></a>
 

lib/internal/errors.js

@@ -210,6 +210,7 @@ class NodeAggregateError extends AggregateError {
 }
 
 const assert = require('internal/assert');
+const { getOptionValue } = require('internal/options');
 
 // Lazily loaded
 let util;
@@ -1686,12 +1687,16 @@ E('ERR_PERFORMANCE_MEASURE_INVALID_OPTIONS', '%s', TypeError);
 E('ERR_REQUIRE_ESM',
   function(filename, hasEsmSyntax, parentPath = null, packageJsonPath = null) {
     hideInternalStackFrames(this);
+    assert(!getOptionValue('--experimental-require-module'));
     let msg = `require() of ES Module ${filename}${parentPath ? ` from ${
       parentPath}` : ''} not supported.`;
+    const hint = '\nOr use --experimental-require-module if the module is synchronous ' +
+      '(contains no top-level await)';
     if (!packageJsonPath) {
       if (StringPrototypeEndsWith(filename, '.mjs'))
         msg += `\nInstead change the require of ${filename} to a dynamic ` +
             'import() which is available in all CommonJS modules.';
+      msg += hint;
       return msg;
     }
     const path = require('path');
@@ -1700,6 +1705,7 @@ E('ERR_REQUIRE_ESM',
     if (hasEsmSyntax) {
       msg += `\nInstead change the require of ${basename} in ${parentPath} to` +
         ' a dynamic import() which is available in all CommonJS modules.';
+      msg += hint;
       return msg;
     }
     msg += `\n${basename} is treated as an ES module file as it is a .js ` +
@@ -1710,6 +1716,7 @@ E('ERR_REQUIRE_ESM',
       'modules, or change "type": "module" to "type": "commonjs" in ' +
       `${packageJsonPath} to treat all .js files as CommonJS (using .mjs for ` +
       'all ES modules instead).\n';
+    msg += hint;
     return msg;
   }, Error);
 E('ERR_SCRIPT_EXECUTION_INTERRUPTED',