Return error when JS_Eval fails (#258)

Author: jeffcharles

crates/cli/src/bytecode.rs

@@ -1,4 +1,4 @@
-use anyhow::Result;
+use anyhow::{anyhow, Result};
 use wasmtime::{Engine, Instance, Linker, Memory, Module, Store};
 use wasmtime_wasi::{WasiCtx, WasiCtxBuilder};
 
@@ -19,7 +19,7 @@ fn create_wasm_env() -> Result<(Store<WasiCtx>, Instance, Memory)> {
     let module = Module::new(&engine, QUICKJS_PROVIDER_MODULE)?;
     let mut linker = Linker::new(&engine);
     wasmtime_wasi::add_to_linker(&mut linker, |s| s)?;
-    let wasi = WasiCtxBuilder::new().build();
+    let wasi = WasiCtxBuilder::new().inherit_stderr().build();
     let mut store = Store::new(&engine, wasi);
     let instance = linker.instantiate(&mut store, &module)?;
     let memory = instance.get_memory(&mut store, "memory").unwrap();
@@ -56,7 +56,9 @@ fn call_compile(
 ) -> Result<u32> {
     let compile_src_fn =
         instance.get_typed_func::<(u32, u32), u32, _>(&mut store, "compile_src")?;
-    let ret_ptr = compile_src_fn.call(&mut store, (js_src_ptr, js_src_len))?;
+    let ret_ptr = compile_src_fn
+        .call(&mut store, (js_src_ptr, js_src_len))
+        .map_err(|_| anyhow!("JS compilation failed"))?;
     Ok(ret_ptr)
 }
 

crates/cli/src/opt.rs

@@ -1,4 +1,4 @@
-use anyhow::{bail, Error, Result};
+use anyhow::{anyhow, bail, Error, Result};
 use binaryen::{CodegenConfig, Module};
 use std::path::Path;
 use wizer::Wizer;
@@ -25,7 +25,8 @@ impl<'a> Optimizer<'a> {
             .allow_wasi(true)?
             .inherit_stdio(true)
             .wasm_bulk_memory(true)
-            .run(self.wasm)?;
+            .run(self.wasm)
+            .map_err(|_| anyhow!("JS compilation failed"))?;
 
         if self.optimize {
             let codegen_cfg = CodegenConfig {

crates/quickjs-wasm-rs/src/js_binding/context.rs

@@ -79,6 +79,8 @@ impl Context {
                 JS_EVAL_FLAG_COMPILE_ONLY as i32,
             )
         };
+        // returns err with details if JS_Eval fails
+        Value::new(self.inner, raw)?;
 
         let mut output_size = 0;
         unsafe {
@@ -434,6 +436,16 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn test_compile_errors_when_invalid_using_syntax() -> Result<()> {
+        let ctx = Context::default();
+        let contents = "await foo;";
+        let res = ctx.compile_global(SCRIPT_NAME, contents);
+        let err = res.unwrap_err();
+        assert!(err.to_string().starts_with("Uncaught SyntaxError"));
+        Ok(())
+    }
+
     #[test]
     fn test_creates_a_value_from_f64() -> Result<()> {
         let ctx = Context::default();