generate error enums correctly, like GLib.UriError

src/bindings/girepository.js

@@ -43,6 +43,7 @@ const { g } = openLib(libName("girepository-1.0", 1), {
     enum_info: {
       get_n_values: $i32($pointer),
       get_value: $pointer($pointer, $i32),
+      get_error_domain: $string($pointer),
     },
     value_info: {
       get_value: $i32($pointer),

src/bindings/glib.js

@@ -0,0 +1,11 @@
+import { libName, openLib } from "../base_utils/ffipp.js";
+
+import { $string, $u32 } from "../base_utils/types.ts";
+
+const { g } = openLib(libName("glib-2.0", 0), {
+  g: {
+    quark_from_string: $u32($string),
+  },
+});
+
+export default g;

src/bindings/mod.js

@@ -1,4 +1,5 @@
+import glib from "./glib.js";
 import gir from "./girepository.js";
 import gobject from "./gobject.js";
 
-export default { ...gir, ...gobject };
+export default { ...gir, ...gobject, ...glib };

src/types/enum.js

@@ -1,16 +1,53 @@
 import g from "../bindings/mod.js";
 import handleInfo from "../handleInfo.js";
+import { getGLibError } from "../utils/error.ts";
+import { getName } from "../utils/string.ts";
 
-export function createEnum(info) {
-  const result = new Object();
-
+function defineValues(target, info) {
   const nValues = g.enum_info.get_n_values(info);
 
   for (let i = 0; i < nValues; i++) {
     const valueInfo = g.enum_info.get_value(info, i);
-    handleInfo(result, valueInfo);
+    handleInfo(target, valueInfo);
     g.base_info.unref(valueInfo);
   }
+}
+
+export function createError(info, error_domain) {
+  const GError = getGLibError();
+
+  const ObjectClass = class extends GError {
+    constructor(props) {
+      super({
+        ...props,
+        domain: g.quark_from_string(error_domain),
+      });
+    }
+
+    [Symbol.hasInstance](instance) {
+      return (instance instanceof GError) && (instance.domain === this.domain);
+    }
+  };
+
+  Object.defineProperty(ObjectClass, "name", {
+    value: getName(info),
+  });
+
+  defineValues(ObjectClass, info);
+
+  return ObjectClass;
+}
+
+export function createEnum(info) {
+  const error_domain = g.enum_info.get_error_domain(info);
+
+  if (error_domain) {
+    return createError(info, error_domain);
+  }
+
+  const result = new Object();
+
+  defineValues(result, info);
 
   return Object.freeze(result);
 }