1 files changed, 85 insertions, 0 deletions
diff --git a/tools/ts/fixtures/intrinsics.d.ts b/tools/ts/fixtures/intrinsics.d.ts
new file mode 100644
index 0000000000..7a0b45ee52
--- /dev/null
+++ b/tools/ts/fixtures/intrinsics.d.ts
@@ -0,0 +1,85 @@
+/**
+ * Gecko XPCOM builtins and utility types.
+ */
+
+/**
+ * Generic IDs are created by most code which passes a nsID to js.
+ * https://searchfox.org/mozilla-central/source/js/xpconnect/src/XPCJSID.cpp#24
+ */
+interface nsID<uuid = string> {
+  readonly number: uuid;
+}
+
+/**
+ * In addition to nsID, interface IIDs support instanceof type guards,
+ * and expose constants defined on the class, including variants from enums.
+ * https://searchfox.org/mozilla-central/source/js/xpconnect/src/XPCJSID.cpp#44
+ */
+type nsJSIID<iface, enums = {}> = nsID & Constants<iface> & enums & {
+  new (_: never): void;
+  prototype: iface;
+}
+
+/** A union of all known IIDs. */
+type nsIID = nsIXPCComponents_Interfaces[keyof nsIXPCComponents_Interfaces];
+
+/** A generic to resolve QueryInterface return type from a nsID (or nsIID). */
+export type nsQIResult<iid> = iid extends { prototype: infer U } ? U : never;
+
+/** XPCOM inout param is passed in as a js object with a value property. */
+type InOutParam<T> = { value: T };
+
+/** XPCOM out param is written to the passed in object's value property. */
+type OutParam<T> = { value?: T };
+
+/** A named type for interfaces to inherit from enums. */
+type Enums<enums> = enums;
+
+/** Callable accepts either form of a [function] interface. */
+type Callable<iface> = iface | Extract<iface[keyof iface], Function>
+
+/** Picks only const number properties from T. */
+type Constants<T> = { [K in keyof T as IfConst<K, T[K]>]: T[K] };
+
+/** Resolves only for keys K whose corresponding type T is a narrow number. */
+type IfConst<K, T> = T extends number ? (number extends T ? never : K) : never;
+
+declare global {
+  // Until we have [ChromeOnly] webidl.
+  interface BrowsingContext {}
+  interface ContentFrameMessageManager {}
+  interface DOMRequest {}
+  interface FrameLoader {}
+  interface JSProcessActorChild {}
+  interface JSProcessActorParent {}
+  interface TreeColumn {}
+  interface WebExtensionContentScript {}
+  interface WebExtensionPolicy {}
+  interface WindowGlobalParent {}
+  interface WindowContext {}
+  interface XULTreeElement {}
+}
+
+// Non-scriptable interfaces referenced from scriptable ones.
+interface nsIAsyncVerifyRedirectReadyCallback {}
+interface nsICRLiteTimestamp {}
+interface nsIInputAvailableCallback {}
+interface nsIScriptElement {}
+interface nsIThreadObserver {}
+interface nsIUDPSocketSyncListener {}
+interface nsIWebAuthnRegisterArgs {}
+interface nsIWebAuthnRegisterPromise {}
+interface nsIWebAuthnSignArgs {}
+interface nsIWebAuthnSignPromise {}
+interface nsIXPCScriptable {}
+
+// Typedefs useful as a quick reference in method signatures.
+type double = number;
+type float = number;
+type i16 = number;
+type i32 = number;
+type i64 = number;
+type u16 = number;
+type u32 = number;
+type u64 = number;
+type u8 = number;