fixes #77: importMetaHook

0-module-and-module-source.emu

@@ -83,6 +83,38 @@ location: https://tc39.es/proposal-compartments/
     </emu-table>
 </emu-clause>
 
+<emu-clause id="sec-meta-properties">
+  <h1>Meta Properties</h1>
+
+  <emu-clause id="sec-meta-properties-runtime-semantics-evaluation" type="sdo">
+    <h1>Runtime Semantics: Evaluation</h1>
+
+    <emu-grammar>ImportMeta : `import` `.` `meta`</emu-grammar>
+    <emu-alg>
+      1. Let _module_ be GetActiveScriptOrModule().
+      1. Assert: _module_ is a Source Text Module Record.
+      1. Let _importMeta_ be _module_.[[ImportMeta]].
+      1. If _importMeta_ is ~empty~, then
+        1. Set _importMeta_ to OrdinaryObjectCreate(*null*).
+        1. <ins>If _module_'s [[ModuleInstance]] internal slot value is *undefined*, then</ins>
+          1. Let _importMetaValues_ be HostGetImportMetaProperties(_module_).
+          1. For each Record { [[Key]], [[Value]] } _p_ of _importMetaValues_, do
+            1. Perform ! CreateDataPropertyOrThrow(_importMeta_, _p_.[[Key]], _p_.[[Value]]).
+          1. Perform HostFinalizeImportMeta(_importMeta_, _module_).
+          1. Set _module_.[[ImportMeta]] to _importMeta_.
+          1. Return _importMeta_.
+        1. <ins>Else,</ins>
+          1. <ins>Let _importMetaHook_ be _module_.[[ModuleInstance]].[[ImportMetaHook]].</ins>
+          1. <ins>Perform ? Call(_importMetaHook_, *undefined*, &laquo; _importMeta_ &raquo;).</ins>
+          1. <ins>Set _module_.[[ImportMeta]] to _importMeta_.</ins>
+          1. <ins>Return _importMeta_.</ins>
+      1. Else,
+        1. Assert: Type(_importMeta_) is Object.
+        1. Return _importMeta_.
+    </emu-alg>
+  </emu-clause>
+</emu-clause>
+
 <emu-clause id="sec-modulesource-records">
     <h1>Module Source Records</h1>
 
@@ -537,27 +569,48 @@ location: https://tc39.es/proposal-compartments/
         </ul>
 
         <emu-clause id="sec-module">
-            <h1>Module ( _moduleSource_, _referral_, _importHook_ [, _importMeta_ ] )</h1>
+            <h1>Module ( _moduleSource_, _handler_ [, _importMeta_ ] )</h1>
             <p>When the `Module` function is called with the arguments _moduleSource_, _referral_, _importHook_ and _importMeta_, the following steps are taken:</p>
             <emu-alg>
                 1. If NewTarget is *undefined*, throw a *TypeError* exception.
                 1. If Type(_moduleSource_) is not Object, throw a *TypeError* exception.
-                1. If IsCallable(_importHook_) is *false*, throw a *TypeError* exception.
-                1. If _importMeta_ is *undefined*, then
-                  1. Set _importMeta_ to *null*.
-                1. Else, if Type(_importMeta_) is not Object, then
-                  1. Throw a *TypeError* exception.
+                _importHook_
                 1. Perform ? RequireInternalSlot(_moduleSource_, [[ModuleSource]]).
-                1. Let _O_ be ? OrdinaryCreateFromConstructor(NewTarget, *"%Module.prototype%"*, « [[Module]], [[ModuleSourceInstance]], [[ImportHook]] »).
                 1. Let _moduleRecord_ to ! CreateModuleRecord(_moduleSource_.[[ModuleSource]]).
-                1. Set _moduleRecord_.[[ModuleInstance]] to _O_.
-                1. Set _moduleRecord_.[[ImportMeta]] to _importMeta_.
-                1. Let _importHookClosure_ be a new Abstract Closure with parameters (_specifier_) that captures _importHook_ and _referral_ and performs the following steps when called
-                  1. Assert: Type(_specifier_) is String.
-                  1. return ? Call(_importHook_, *undefined*, « _specifier_, _referral_ »).
-                1. Set _O_.[[Module]] to _moduleRecord_.
+                1. If Type(_handler_) is Object, then
+                  1. If _handler_ is *null, throw a TypeError exception.
+                  1. Let _importHook_ be ? GetMethod(handler, "importHook").
+                  1. If _importHook_ is *undefined*, then
+                    1. Let _importHookClosure_ be a new Abstract Closure with parameters (_specifier_) that captures _moduleRecord_ and performs the following steps when called
+                      1. Assert: Type(_specifier_) is String.
+                      1. NOTE: Default import hook.
+                      1. Let _promiseCapability_ be ! NewPromiseCapability(%Promise%).
+                      1. Perform HostImportModuleDynamically(_moduleRecord_, _specifier_, _promiseCapability_).
+                      1. Return _promiseCapability_.[[Promise]].
+                  1. Else,
+                    1. Let _importHookClosure_ be a new Abstract Closure with parameters (_specifier_) that captures _importHook_ and _handler_ and performs the following steps when called
+                      1. Assert: Type(_specifier_) is String.
+                      1. return ? Call(_importHook_, _handler_, « _specifier_ »).
+                  1. Let _importMetaHook_ be ? GetMethod(handler, "importMetaHook").
+                  1. If _importMetaHook_ is *undefined*, then
+                    1. Let _importHookClosure_ be a new Abstract Closure with parameters (_importMeta_) that captures _moduleRecord_ and performs the following steps when called
+                      1. NOTE: Default import.meta hook.
+                      1. Let _importMetaValues_ be HostGetImportMetaProperties(_moduleRecord_).
+                      1. For each Record { [[Key]], [[Value]] } _p_ of _importMetaValues_, do
+                        1. Perform ! CreateDataPropertyOrThrow(_importMeta_, _p_.[[Key]], _p_.[[Value]]).
+                      1. Perform HostFinalizeImportMeta(_importMeta_, _moduleRecord_).
+                      1. Set _moduleRecord_.[[ImportMeta]] to _importMeta_.
+                      1. Return _importMeta_.
+                  1. Else,
+                    1. Let _importHookClosure_ be a new Abstract Closure with parameters (_importMeta_) that captures _importMetaHook_ and _handler_ and performs the following steps when called
+                      1. return ? Call(_importMetaHook_, _handler_, &laquo; _importMeta_ &raquo;).
+                1. Let _O_ be ? OrdinaryCreateFromConstructor(NewTarget, *"%Module.prototype%"*, « [[Module]], [[ModuleSourceInstance]], [[HooksThisValue]], [[ImportHook]], [[ImportMetaHook]] »).
                 1. Set _O_.[[ModuleSourceInstance]] to _moduleSource_.
                 1. Set _O_.[[ImportHook]] be CreateBuiltinFunction(_importHookClosure_, 1, *""*, &laquo; &raquo;).
+                1. Set _O_.[[ImportMetaHook]] be CreateBuiltinFunction(_importMetaHookClosure_, 0, *""*, &laquo; &raquo;).
+                1. Set _O_.[[HooksThisValue]] be _handler_.
+                1. Set _moduleRecord_.[[ModuleInstance]] to _O_.
+                1. Set _O_.[[Module]] to _moduleRecord_.
                 1. Return _O_.
             </emu-alg>
         </emu-clause>
@@ -632,11 +685,21 @@ location: https://tc39.es/proposal-compartments/
                         <td>ModuleSource Instance or *null*</td>
                         <td>The ModuleSource Instance associated to Module Instance. *null* if this Module Instance has not a source associated to it.</td>
                     </tr>
+                    <tr>
+                        <td>[[HooksThisValue]]</td>
+                        <td>an ECMAScript language value</td>
+                        <td>This is the *this* value used for invocation of the hook functions.</td>
+                    </tr>
                     <tr>
                         <td>[[ImportHook]]</td>
                         <td>a callable Object</td>
                         <td>The callable Object associated to the [[Module]] record to resolve module dependencies.</td>
                     </tr>
+                    <tr>
+                        <td>[[ImportMetaHook]]</td>
+                        <td>a callable Object</td>
+                        <td>The callable Object associated to the [[Module]] record to provide import.meta value.</td>
+                    </tr>
                 </tbody>
             </table>
         </emu-table>