Implement support for [LegacyWindowAlias] and [NoInterfaceObject]

Fixed #187.

Author: ExE-Boss

README.md

@@ -456,6 +456,8 @@ webidl2js is implementing an ever-growing subset of the Web IDL specification. S
 - `[EnforceRange]`
 - `[LegacyArrayClass]`
 - `[LegacyUnenumerableNamedProperties]`
+- `[LegacyWindowAlias]`
+- `[NoInterfaceObject]`
 - `[OverrideBuiltins]`
 - `[PutForwards]`
 - `[Replaceable]`
@@ -477,7 +479,6 @@ Notable missing features include:
 - `[Default]` (for `toJSON()` operations)
 - `[Global]`'s various consequences, including the named properties object and `[[SetPrototypeOf]]`
 - `[Exposed]`
-- `[LegacyWindowAlias]`
 - `[LenientSetter]`
 - `[LenientThis]`
 - `[NamedConstructor]`

lib/constructs/interface.js

@@ -76,6 +76,49 @@ class Interface {
     if (global && !global.rhs) {
       throw new Error(`[Global] must take an identifier or an identifier list in interface ${this.name}`);
     }
+
+    const exposed = utils.getExtAttr(this.idl.extAttrs, "Exposed");
+    if (exposed) {
+      if (!exposed.rhs || (exposed.rhs.type !== "identifier" && exposed.rhs.type !== "identifier-list")) {
+        throw new Error(`[Exposed] must take an identifier or an identifier list in interface ${this.name}`);
+      }
+
+      if (exposed.rhs.type === "identifier") {
+        this.exposed = new Set([exposed.rhs.value]);
+      } else {
+        this.exposed = new Set(exposed.rhs.value.map(token => token.value));
+      }
+    } else {
+      this.exposed = new Set();
+    }
+
+    if (!exposed && !utils.getExtAttr(this.idl.extAttrs, "NoInterfaceObject")) {
+      throw new Error(`Interface ${this.name} has neither [Exposed] nor [NoInterfaceObject]`);
+    }
+
+    const legacyWindowAlias = utils.getExtAttr(this.idl.extAttrs, "LegacyWindowAlias");
+    if (legacyWindowAlias) {
+      if (utils.getExtAttr(this.idl.extAttrs, "NoInterfaceObject")) {
+        throw new Error(`Interface ${this.name} has [LegacyWindowAlias] and [NoInterfaceObject]`);
+      }
+
+      if (!this.exposed.has("Window")) {
+        throw new Error(`Interface ${this.name} has [LegacyWindowAlias] without [Exposed=Window]`);
+      }
+
+      if (!legacyWindowAlias.rhs ||
+        (legacyWindowAlias.rhs.type !== "identifier" && legacyWindowAlias.rhs.type !== "identifier-list")) {
+        throw new Error(`[LegacyWindowAlias] must take an identifier or an identifier list in interface ${this.name}`);
+      }
+
+      if (legacyWindowAlias.rhs.type === "identifier") {
+        this.legacyWindowAliases = new Set([legacyWindowAlias.rhs.value]);
+      } else {
+        this.legacyWindowAliases = new Set(legacyWindowAlias.rhs.value.map(token => token.value));
+      }
+    } else {
+      this.legacyWindowAliases = null;
+    }
   }
 
   // whence is either "instance" or "prototype"
@@ -1420,7 +1463,7 @@ class Interface {
     const { idl, name } = this;
 
     this.str += `
-      exports.install = function install(globalObject) {
+      exports.install = (globalObject, globalName) => {
     `;
 
     if (idl.inheritance) {
@@ -1444,12 +1487,39 @@ class Interface {
           globalObject[ctorRegistrySymbol] = Object.create(null);
         }
         globalObject[ctorRegistrySymbol][interfaceName] = ${name};
+    `;
 
+    if (!utils.getExtAttr(this.idl.extAttrs, "NoInterfaceObject")) {
+      this.str += `
         Object.defineProperty(globalObject, interfaceName, {
           configurable: true,
           writable: true,
           value: ${name}
         });
+      `;
+
+      if (this.legacyWindowAliases) {
+        this.str += `
+          if (globalName === "Window") {
+        `;
+
+        for (const legacyWindowAlias of this.legacyWindowAliases) {
+          this.str += `
+            Object.defineProperty(globalObject, "${legacyWindowAlias}", {
+              configurable: true,
+              writable: true,
+              value: ${name}
+            });
+          `;
+        }
+
+        this.str += `
+          }
+        `;
+      }
+    }
+
+    this.str += `
       };
     `;
   }