fix: Allow processors to add package imports

lib/constructs/attribute.js

@@ -79,7 +79,7 @@ class Attribute {
       let idlConversion;
       if (typeof this.idl.idlType.idlType === "string" && !this.idl.idlType.nullable &&
           this.ctx.enumerations.has(this.idl.idlType.idlType)) {
-        requires.add(this.idl.idlType.idlType);
+        requires.addRelative(this.idl.idlType.idlType);
         idlConversion = `
           V = \`\${V}\`;
           if (!${this.idl.idlType.idlType}.enumerationValues.has(V)) {

lib/constructs/dictionary.js

@@ -95,7 +95,7 @@ class Dictionary {
     `;
 
     if (this.idl.inheritance) {
-      this.requires.add(this.idl.inheritance);
+      this.requires.addRelative(this.idl.inheritance);
     }
     this.str = `
       ${this.requires.generate()}

lib/constructs/interface.js

@@ -503,11 +503,11 @@ class Interface {
     this.requires.addRaw("ctorRegistry", "utils.ctorRegistrySymbol");
 
     if (this.idl.inheritance !== null) {
-      this.requires.add(this.idl.inheritance);
+      this.requires.addRelative(this.idl.inheritance);
     }
 
     for (const iface of this.consequentialInterfaces()) {
-      this.requires.add(iface);
+      this.requires.addRelative(iface);
     }
 
     this.str = `

lib/parameters.js

@@ -131,7 +131,7 @@ module.exports.generateOverloadConversions = function (ctx, typeOfOp, name, pare
           // Avoid requiring the interface itself
           if (iface !== parent.name) {
             fn = `is${iface}`;
-            requires.add(iface, "is");
+            requires.addRelative(iface, "is");
           } else {
             fn = "module.exports.is";
           }

lib/types.js

@@ -122,7 +122,7 @@ function generateTypeConversion(ctx, name, idlType, argAttrs = [], parentName, e
     // Avoid requiring the interface itself
     if (idlType.idlType !== parentName) {
       fn = `convert${idlType.idlType}`;
-      requires.add(idlType.idlType, "convert");
+      requires.addRelative(idlType.idlType, "convert");
     } else {
       fn = `module.exports.convert`;
     }
@@ -174,7 +174,7 @@ function generateTypeConversion(ctx, name, idlType, argAttrs = [], parentName, e
         // Avoid requiring the interface itself
         if (iface !== parentName) {
           fn = `is${iface}`;
-          requires.add(iface, "is");
+          requires.addRelative(iface, "is");
         } else {
           fn = "module.exports.is";
         }

lib/utils.js

@@ -1,4 +1,5 @@
 "use strict";
+const { extname } = require("path");
 
 function getDefault(dflt) {
   switch (dflt.type) {
@@ -65,14 +66,36 @@ function stringifyPropertyName(prop) {
   return typeof prop === "symbol" ? symbolName(prop) : JSON.stringify(propertyName(prop));
 }
 
+function toKey(type, func = "") {
+  return String(func + type).replace(/[./-]+/g, " ").trim().replace(/ /g, "_");
+}
+
+const PACKAGE_NAME_REGEX = /^(?:@([^/]+?)[/])?([^/]+?)$/u;
+
 class RequiresMap extends Map {
   constructor(ctx) {
     super();
     this.ctx = ctx;
   }
 
-  add(type, func = "") {
-    const key = (func + type).replace(/[./-]+/g, " ").trim().replace(/ /g, "_");
+  add(name, func = "") {
+    const key = toKey(name, func);
+
+    // If `name` is a package name or has a file extension, then use it as-is,
+    // otherwise append the `.js` file extension:
+    const importPath = PACKAGE_NAME_REGEX.test(name) || extname(name) ? name : `${name}.js`;
+    let req = `require(${JSON.stringify(importPath)})`;
+
+    if (func) {
+      req += `.${func}`;
+    }
+
+    this.addRaw(key, req);
+    return key;
+  }
+
+  addRelative(type, func = "") {
+    const key = toKey(type, func);
 
     const path = type.startsWith(".") ? type : `./${type}`;
     let req = `require("${path}.js")`;