implement direct and indirect eval

src/client/shared/eval.ts

@@ -1,24 +1,47 @@
 import { ScramjetClient, ProxyCtx } from "../client";
-import { rewriteJs } from "../shared";
+import { config, rewriteJs } from "../shared";
 
 function rewriteFunction(ctx: ProxyCtx) {
-    for (const i in ctx.args) {
-        ctx.args[i] = rewriteJs(ctx.args[i]);
-    }
+	for (const i in ctx.args) {
+		ctx.args[i] = rewriteJs(ctx.args[i]);
+	}
 
-    ctx.return(ctx.fn(...ctx.args));
+	ctx.return(ctx.fn(...ctx.args));
 }
 
 export default function (client: ScramjetClient, self: Self) {
-    client.Proxy("Function", {
-        apply(ctx) {
-            rewriteFunction(ctx);
-        },
+	client.Proxy("Function", {
+		apply(ctx) {
+			rewriteFunction(ctx);
+		},
 
-        construct(ctx) {
-            rewriteFunction(ctx);
-        },
-    });
+		construct(ctx) {
+			rewriteFunction(ctx);
+		},
+	});
 
-    Function.prototype.constructor = Function;
-}
+	Function.prototype.constructor = Function;
+
+	// used for proxying *direct eval*
+	// eval("...") -> eval($scramjet$rewrite("..."))
+	Object.defineProperty(self, config.rewritefn, {
+		value: function (js: any) {
+			if (typeof js !== "string") return js;
+
+			const rewritten = rewriteJs(js, client.url);
+
+			return rewritten;
+		},
+		writable: false,
+		configurable: false,
+	});
+}
+
+export function indirectEval(this: ScramjetClient, js: any) {
+	// > If the argument of eval() is not a string, eval() returns the argument unchanged
+	if (typeof js !== "string") return js;
+
+	const indirection = this.global.eval;
+
+	return indirection(rewriteJs(js, this.url) as string);
+}