Temporarily make [Exposed] and globalNames non-required

This reverts the breaking changes introduced in #191, since it was accidentally released as a minor version in v15.2.0, while keeping the functionality.

Author: domenic

README.md

@@ -270,6 +270,8 @@ This method creates a brand new wrapper constructor and prototype and attach it
 
 The second argument `globalNames` is an array containing the [global names](https://heycam.github.io/webidl/#dfn-global-name) of the interface that `globalObject` implements. This is used for the purposes of deciding which interfaces are [exposed](https://heycam.github.io/webidl/#dfn-exposed). For example, this array should be `["Window"]` for a [`Window`](https://html.spec.whatwg.org/multipage/window-object.html#window) global object. But for a [`DedicatedWorkerGlobalScope`](https://html.spec.whatwg.org/multipage/workers.html#dedicatedworkerglobalscope) global object, this array should be `["Worker", "DedicatedWorker"]`. Note that we do not yet implement [`[SecureContext]`](https://heycam.github.io/webidl/#SecureContext), so the "exposed" check is not fully implemented.
 
+Temporarily, until the next major release, `globalNames` defaults to `["Window"]`.
+
 #### `create(globalObject, constructorArgs, privateData)`
 
 Creates a new instance of the wrapper class and corresponding implementation class, passing in the `globalObject`, the `constructorArgs` array and `privateData` object to the implementation class constructor. Then returns the wrapper class.
@@ -304,10 +306,12 @@ The resulting function has an _objectReference_ property, which is the same obje
 
 If any part of the conversion fails, _context_ can be used to describe the provided value in any resulting error message.
 
-#### `install(globalObject)`
+#### `install(globalObject, globalNames)`
 
 If this callback interface has constants, then this method creates a brand new legacy callback interface object and attaches it to the passed `globalObject`. Otherwise, this method is a no-op.
 
+The second argument `globalNames` is the same as for [the `install()` export for interfaces](#installglobalobject-globalnames). (However, it does not have a default.)
+
 ### For dictionaries
 
 #### `convert(value, { context })`
@@ -462,7 +466,7 @@ webidl2js is implementing an ever-growing subset of the Web IDL specification. S
 - Variadic arguments
 - `[Clamp]`
 - `[EnforceRange]`
-- `[Exposed]`
+- `[Exposed]` (temporarily defaulting to `[Exposed=Window]`)
 - `[LegacyArrayClass]`
 - `[LegacyUnenumerableNamedProperties]`
 - `[LegacyWindowAlias]`

lib/constructs/interface.js

@@ -92,8 +92,13 @@ class Interface {
       this.exposed = new Set();
     }
 
-    if (!exposed && !utils.getExtAttr(this.idl.extAttrs, "NoInterfaceObject")) {
-      throw new Error(`Interface ${this.name} has neither [Exposed] nor [NoInterfaceObject]`);
+    // TODO: put back in next major version.
+    // if (!exposed && !utils.getExtAttr(this.idl.extAttrs, "NoInterfaceObject")) {
+    //   throw new Error(`Interface ${this.name} has neither [Exposed] nor [NoInterfaceObject]`);
+    // }
+    // For now:
+    if (!exposed) {
+      this.exposed = new Set(["Window"]);
     }
 
     const legacyWindowAlias = utils.getExtAttr(this.idl.extAttrs, "LegacyWindowAlias");
@@ -1486,7 +1491,7 @@ class Interface {
     this.str += `
       const exposed = new Set(${JSON.stringify([...this.exposed])});
 
-      exports.install = (globalObject, globalNames) => {
+      exports.install = (globalObject, globalNames = ["Window"]) => {
         if (!globalNames.some(globalName => exposed.has(globalName))) {
           return;
         }