improve readme + remove todo

Author: FrancoGiachetta

examples/wasm-demo-cairo1/README.md

@@ -1,9 +1,10 @@
-# Demo of `cairo-vm` on WebAssembly
+# Demo of `cairo-vm` on WebAssembly (Cairo 1)
 
 While cairo-vm is compatible with WebAssembly, it doesn't implement any bindings to it.
-Instead, create a new WebAssembly crate with cairo-vm as a dependency and implement the required functionality there.
+Instead, create a new WebAssembly crate with cairo-vm and cairo1-run as dependencies and implement the required functionality there.
 
-Since mimalloc is not automatically compilable to WebAssembly, the cairo-vm dependency should disable the default features, which will in turn disable mimalloc.
+Since mimalloc is not automatically compilable to WebAssembly, the cairo-vm dependency should disable the default features, which will in turn disable mimalloc. Simliar to this, WebAssembly is
+not compatible with rust standard library. For this reason, cairo1-run should also disable the default features.
 
 A working example is provided in this repository.
 
@@ -22,10 +23,18 @@ To compile and run the example you need:
 
 To build the example, first you need to compile your Cairo Program, using either cairo 1 or cairo 2 compiler:
 
+If cairo 1 is used:
+
 ```sh
 cairo-compile -rs ../../cairo_programs/cairo-1-programs/bitwise.cairo ../../cairo_programs/cairo-1-programs/bitwise.sierra
 ```
 
+If cairo 2 is used:
+
+```sh
+cairo-compile -r ../../cairo_programs/cairo-1-programs/bitwise.cairo ../../cairo_programs/cairo-1-programs/bitwise.sierra
+```
+
 > WARNING: This example uses `cairo1-run::cairo_run_program` which expectes the program to be compiled with debug names. By default, `cairo-compile` does not include debug names in sierra. Due to this, the flag `-r` or `--replace-ids` is needed.
 
 compile the WebAssembly package:

examples/wasm-demo-cairo1/src/lib.rs

@@ -16,16 +16,14 @@ pub fn start() {
     crate::utils::set_panic_hook();
 }
 
-// TODO: check why this is needed. Seems wasm-bindgen expects us to use
-// `std::error::Error` even if it's not yet in `core`
 macro_rules! wrap_error {
     ($xp: expr) => {
-        $xp.map_err(|e| JsError::new(&format!("Error from CairoRunner: {}", e.to_string())))
+        $xp.map_err(|e| JsValue::from_str(&format!("Error from CairoRunner: {}", e.to_string())))
     };
 }
 
 #[wasm_bindgen(js_name = runCairoProgram)]
-pub fn run_cairo_program() -> Result<String, JsError> {
+pub fn run_cairo_program() -> Result<String, JsValue> {
     let cairo_run_config = Cairo1RunConfig {
         layout: LayoutName::all_cairo,
         relocate_mem: true,
@@ -36,7 +34,7 @@ pub fn run_cairo_program() -> Result<String, JsError> {
 
     let sierra_program = {
         let program_str = include_str!("../../../cairo_programs/cairo-1-programs/bitwise.sierra");
-        ProgramParser::new().parse(program_str)?
+        wrap_error!(ProgramParser::new().parse(program_str))?
     };
 
     let (_, _, serialized_output) = wrap_error!(cairo1_run::cairo_run_program(
@@ -48,5 +46,5 @@ pub fn run_cairo_program() -> Result<String, JsError> {
 
     log(&output);
 
-    Ok("output".to_string())
+    Ok(output)
 }