esm: irp type implementation

Refs: https://github.com/GeoffreyBooth/node-import-file-specifier-resolution-proposal
Refs: nodejs/modules#180
Refs: #6
Refs: #12
Refs: #28
Co-authored-by: Myles Borins <MylesBorins@google.com>
Co-authored-by: John-David Dalton <john.david.dalton@gmail.com>

.eslintrc.js

@@ -38,6 +38,8 @@ module.exports = {
     {
       files: [
         'doc/api/esm.md',
+        'test/es-module/test-esm-type-flag.js',
+        'test/es-module/test-esm-type-flag-alias.js',
         '*.mjs',
         'test/es-module/test-esm-example-loader.js',
       ],

doc/api/cli.md

@@ -511,6 +511,18 @@ added: v2.4.0
 
 Track heap object allocations for heap snapshots.
 
+### `-m`, `--type=type`
+
+When using `--experimental-modules`, this informs the module resolution type
+to interpret the top-level entry into Node.js.
+
+Works with stdin, `--eval`, `--print` as well as standard execution.
+
+Valid values are `"commonjs"` and `"module"`, where the default is to infer
+from the file extension and package type boundary.
+
+`-m` is an alias for `--type=module`.
+
 ### `--use-bundled-ca`, `--use-openssl-ca`
 <!-- YAML
 added: v6.11.0
@@ -904,7 +916,7 @@ greater than `4` (its current default value). For more information, see the
 [debugger]: debugger.html
 [debugging security implications]: https://nodejs.org/en/docs/guides/debugging-getting-started/#security-implications
 [emit_warning]: process.html#process_process_emitwarning_warning_type_code_ctor
-[experimental ECMAScript Module]: esm.html#esm_loader_hooks
+[experimental ECMAScript Module]: esm.html#esm_experimental_loader_hooks
 [libuv threadpool documentation]: http://docs.libuv.org/en/latest/threadpool.html
 [remote code execution]: https://www.owasp.org/index.php/Code_Injection
 [secureProtocol]: tls.html#tls_tls_createsecurecontext_options

doc/api/errors.md

@@ -1267,6 +1267,11 @@ An invalid or unexpected value was passed in an options object.
 
 An invalid or unknown file encoding was passed.
 
+<a id="ERR_INVALID_PACKAGE_CONFIG"></a>
+### ERR_INVALID_PACKAGE_CONFIG
+
+An invalid `package.json` file was found which failed parsing.
+
 <a id="ERR_INVALID_PERFORMANCE_MARK"></a>
 ### ERR_INVALID_PERFORMANCE_MARK
 
@@ -1449,26 +1454,19 @@ a `dynamicInstantiate` hook.
 A `MessagePort` was found in the object passed to a `postMessage()` call,
 but not provided in the `transferList` for that call.
 
-<a id="ERR_MISSING_MODULE"></a>
-### ERR_MISSING_MODULE
-
-> Stability: 1 - Experimental
-
-An [ES6 module][] could not be resolved.
-
 <a id="ERR_MISSING_PLATFORM_FOR_WORKER"></a>
 ### ERR_MISSING_PLATFORM_FOR_WORKER
 
 The V8 platform used by this instance of Node.js does not support creating
 Workers. This is caused by lack of embedder support for Workers. In particular,
 this error will not occur with standard builds of Node.js.
 
-<a id="ERR_MODULE_RESOLUTION_LEGACY"></a>
-### ERR_MODULE_RESOLUTION_LEGACY
+<a id="ERR_MODULE_NOT_FOUND"></a>
+### ERR_MODULE_NOT_FOUND
 
 > Stability: 1 - Experimental
 
-A failure occurred resolving imports in an [ES6 module][].
+An [ESM module][] could not be resolved.
 
 <a id="ERR_MULTIPLE_CALLBACK"></a>
 ### ERR_MULTIPLE_CALLBACK
@@ -2220,6 +2218,32 @@ A non-specific HTTP/2 error has occurred.
 Used in the `repl` in case the old history file is used and an error occurred
 while trying to read and parse it.
 
+<a id="ERR_INVALID_REPL_TYPE"></a>
+### ERR_INVALID_REPL_TYPE
+
+> Stability: 1 - Experimental
+
+The `--type=...` flag is not compatible with the Node.js REPL.
+
+<a id="ERR_TYPE_MISMATCH"></a>
+### ERR_TYPE_MISMATCH
+
+> Stability: 1 - Experimental
+
+The `--type=commonjs` flag was used to attempt to execute an `.mjs` file or
+a `.js` file where the nearest parent `package.json` contains
+`"type": "module"`; or
+the `--type=module` flag was used to attempt to execute a `.cjs` file or
+a `.js` file where the nearest parent `package.json` either lacks a `"type"`
+field or contains `"type": "commonjs"`.
+
+<a id="ERR_INVALID_TYPE_FLAG"></a>
+### ERR_INVALID_TYPE_FLAG
+
+> Stability: 1 - Experimental
+
+An invalid `--type=...` flag value was provided.
+
 <a id="ERR_MISSING_DYNAMIC_INSTANTIATE_HOOK"></a>
 #### ERR_MISSING_DYNAMIC_INSTANTIATE_HOOK
 
@@ -2250,7 +2274,6 @@ size.
 This `Error` is thrown when a read is attempted on a TTY `WriteStream`,
 such as `process.stdout.on('data')`.
 
-
 [`'uncaughtException'`]: process.html#process_event_uncaughtexception
 [`--force-fips`]: cli.html#cli_force_fips
 [`Class: assert.AssertionError`]: assert.html#assert_class_assert_assertionerror