[core] restore old postmessage behavior

Author: velzie

packages/scramjet/packages/core/rewriter/js/src/changes.rs

@@ -78,6 +78,7 @@ pub enum JsChangeType<'alloc: 'data, 'data> {
 		op: AssignmentOperator,
 	},
 
+	SetRealmFn,
 	/// insert `)`
 	ClosingParen {
 		semi: bool,
@@ -251,6 +252,7 @@ impl<'alloc: 'data, 'data> Transform<'data> for JsChange<'alloc, 'data> {
 			]),
 			Ty::ImportFn => LL::replace(transforms![&cfg.importfn, "(\"", &flags.base, "\","]),
 			Ty::MetaFn => LL::replace(transforms![&cfg.metafn, "(import.meta,\"", &flags.base, "\")"]),
+			Ty::SetRealmFn => LL::replace(transforms!["$scramjet$setrealmfn", "({})."]),
 			Ty::AssignmentLeft { name, op } => LL::replace(transforms![
 				"((t)=>",
 				&cfg.trysetfn,

packages/scramjet/packages/core/rewriter/js/src/rewrite.rs

@@ -29,6 +29,8 @@ pub(crate) enum RewriteType<'alloc: 'data, 'data> {
 	/// `cfg.metafn("cfg.base")`
 	MetaFn,
 
+	SetRealmFn,
+
 	/// `location` -> `$sj_location`
 	RewriteProperty {
 		ident: Atom<'data>,
@@ -237,6 +239,7 @@ impl<'alloc: 'data, 'data> RewriteType<'alloc, 'data> {
 					replace: true
 				}
 			)],
+			Self::SetRealmFn => smallvec![change!(span, SetRealmFn)],
 			Self::ImportFn => smallvec![change!(span, ImportFn)],
 			Self::MetaFn => smallvec![change!(span, MetaFn)],
 			Self::ScramErr { ident } => smallvec![change!(span!(end), ScramErrFn { ident })],

packages/scramjet/packages/core/rewriter/js/src/visitor.rs

@@ -472,11 +472,17 @@ where
 				if s.property.name == "postMessage" {
 					// include the "postMessage" and the dot before it in the inner span
 					// if `postMessage?.` remove the dot and the question mark
-					let offset = if s.optional { 2 } else { 1 };
+					// let offset = if s.optional { 2 } else { 1 };
 
-					self.jschanges.add(rewrite!(s.span, WrapPostMessage {
-						inner: Span::new(s.property.span.start - offset, s.property.span.end),
-					}));
+					// self.jschanges.add(rewrite!(s.span, WrapPostMessage {
+					// 	inner: Span::new(s.property.span.start - offset, s.property.span.end),
+					// }));
+					if s.property.name == "postMessage" {
+										self.jschanges.add(rewrite!(s.property.span, SetRealmFn));
+
+										walk::walk_expression(self, &s.object);
+										return; // unwise to walk the rest of the tree
+									}
 
 					// walk::walk_expression(self, &s.object);
 					return; // unwise to walk the rest of the tree

packages/scramjet/packages/core/src/client/shared/postmessage.ts

@@ -1,6 +1,7 @@
 import { iswindow } from "@client/entry";
 import { SCRAMJETCLIENT } from "@/symbols";
 import { ScramjetClient } from "@client/index";
+import { POLLUTANT } from "./realm";
 
 export default function (client: ScramjetClient, self: Self) {
 	if (iswindow)
@@ -14,20 +15,20 @@ export default function (client: ScramjetClient, self: Self) {
 
 				let pollutant;
 
-				// if (typeof ctx.args[0] === "object" && ctx.args[0] !== null) {
-				// 	pollutant = ctx.args[0]; // try to use the first object we can find because it's more reliable
-				// } else if (typeof ctx.args[2] === "object" && ctx.args[2] !== null) {
-				// 	pollutant = ctx.args[2]; // next try to use transfer
-				// } else if (
-				// 	ctx.this &&
-				// 	POLLUTANT in ctx.this &&
-				// 	typeof ctx.this[POLLUTANT] === "object" &&
-				// 	ctx.this[POLLUTANT] !== null
-				// ) {
-				// 	pollutant = ctx.this[POLLUTANT]; // lastly try to use the object from $setrealm
-				// } else {
-				pollutant = {}; // give up
-				// }
+				if (typeof ctx.args[0] === "object" && ctx.args[0] !== null) {
+					pollutant = ctx.args[0]; // try to use the first object we can find because it's more reliable
+				} else if (typeof ctx.args[2] === "object" && ctx.args[2] !== null) {
+					pollutant = ctx.args[2]; // next try to use transfer
+				} else if (
+					ctx.this &&
+					POLLUTANT in ctx.this &&
+					typeof ctx.this[POLLUTANT] === "object" &&
+					ctx.this[POLLUTANT] !== null
+				) {
+					pollutant = ctx.this[POLLUTANT]; // lastly try to use the object from $setrealm
+				} else {
+					pollutant = {}; // give up
+				}
 
 				// and now we can steal Function from the caller's realm
 				const {
@@ -55,13 +56,15 @@ export default function (client: ScramjetClient, self: Self) {
 					$scramjet$origin: callerClient.url.origin,
 					$scramjet$data: ctx.args[0],
 				};
-				// console.error("?");
+				// console.error("?", ctx.args);
 				// eval("debugger");
 
 				// * origin because obviously
 				if (typeof ctx.args[1] === "string") ctx.args[1] = "*";
 				if (typeof ctx.args[1] === "object") ctx.args[1].targetOrigin = "*";
 
+				console.log("postmessage proxy", ctx.args);
+
 				ctx.return(wrappedPostMessage.call(ctx.fn, ...ctx.args));
 			},
 		});
@@ -75,6 +78,7 @@ export default function (client: ScramjetClient, self: Self) {
 		apply(ctx) {
 			// origin/source doesn't need to be preserved - it's null in the message event
 
+			console.error("postmessagfef", ctx.this, ctx.args);
 			ctx.args[0] = {
 				$scramjet$messagetype: "worker",
 				$scramjet$data: ctx.args[0],

packages/scramjet/packages/core/src/client/shared/realm.ts

@@ -0,0 +1,25 @@
+import { ScramjetClient } from "@client/index";
+
+export const POLLUTANT = Symbol.for("scramjet realm pollutant");
+
+export default function (client: ScramjetClient, self: typeof globalThis) {
+	// object.$setrealm({}).postMessage(...)
+	// the empty object is the "pollutant" which can reconstruct the real realm
+	// i explain more in postmessage.ts
+	Object.defineProperty(self.Object.prototype, "$scramjet$setrealmfn", {
+		value(pollution: object) {
+			// this is bad!! sites could detect this
+			Object.defineProperty(this, POLLUTANT, {
+				value: pollution,
+				writable: false,
+				configurable: true,
+				enumerable: false,
+			});
+
+			return this;
+		},
+		writable: true,
+		configurable: true,
+		enumerable: false,
+	});
+}