Avoid crashes on ES module resolution when module not found (#1546)

5 files changed, 22 insertions, 3 deletions

diff --git a/libdeno/binding.cc b/libdeno/binding.cc
index d292f2638..000529304 100644
--- a/libdeno/binding.cc
+++ b/libdeno/binding.cc
@@ -558,7 +558,11 @@ v8::MaybeLocal<v8::Module> ResolveCallback(v8::Local<v8::Context> context,
 
   if (d->resolve_module_.IsEmpty()) {
     // Resolution Error.
-    isolate->ThrowException(v8_str("module resolution error"));
+    std::stringstream err_ss;
+    err_ss << "NotFound: Cannot resolve module \"" << specifier_c
+           << "\" from \"" << referrer_filename << "\"";
+    auto resolve_error = v8_str(err_ss.str().c_str());
+    isolate->ThrowException(resolve_error);
     return v8::MaybeLocal<v8::Module>();
   } else {
     auto module = d->resolve_module_.Get(isolate);
@@ -612,6 +616,8 @@ bool ExecuteMod(v8::Local<v8::Context> context, const char* js_filename,
   auto module = maybe_module.ToLocalChecked();
   auto maybe_ok = module->InstantiateModule(context, ResolveCallback);
   if (maybe_ok.IsNothing()) {
+    DCHECK(try_catch.HasCaught());
+    HandleException(context, try_catch.Exception());
     return false;
   }
 
diff --git a/src/isolate.rs b/src/isolate.rs
index bbd52c64d..5100ac490 100644
--- a/src/isolate.rs
+++ b/src/isolate.rs
@@ -403,8 +403,15 @@ extern "C" fn resolve_cb(
   debug!("module_resolve callback {} {}", specifier, referrer);
   let isolate = unsafe { Isolate::from_raw_ptr(user_data) };
 
-  let out =
-    code_fetch_and_maybe_compile(&isolate.state, specifier, referrer).unwrap();
+  let maybe_out =
+    code_fetch_and_maybe_compile(&isolate.state, specifier, referrer);
+
+  if maybe_out.is_err() {
+    // Resolution failure
+    return;
+  }
+
+  let out = maybe_out.unwrap();
 
   let filename = CString::new(out.filename.clone()).unwrap();
   let filename_ptr = filename.as_ptr() as *const i8;
diff --git a/tests/error_009_missing_js_module.js b/tests/error_009_missing_js_module.js
new file mode 100644
index 000000000..e6ca88934
--- /dev/null
+++ b/tests/error_009_missing_js_module.js
@@ -0,0 +1 @@
+import "./bad-module.js";
diff --git a/tests/error_009_missing_js_module.js.out b/tests/error_009_missing_js_module.js.out
new file mode 100644
index 000000000..1bcd9099e
--- /dev/null
+++ b/tests/error_009_missing_js_module.js.out
@@ -0,0 +1 @@
+NotFound: Cannot resolve module "./bad-module.js" from "[WILDCARD]/tests/error_009_missing_js_module.js"
diff --git a/tests/error_009_missing_js_module.test b/tests/error_009_missing_js_module.test
new file mode 100644
index 000000000..b16bb232b
--- /dev/null
+++ b/tests/error_009_missing_js_module.test
@@ -0,0 +1,4 @@
+args: tests/error_009_missing_js_module.js
+check_stderr: true
+exit_code: 1
+output: tests/error_009_missing_js_module.js.out
\ No newline at end of file