1 files changed, 17 insertions, 0 deletions
diff --git a/cli/ops/runtime.rs b/cli/ops/runtime.rs
index a85ce4011..e47b40792 100644
--- a/cli/ops/runtime.rs
+++ b/cli/ops/runtime.rs
@@ -6,11 +6,13 @@ use crate::state::State;
 use crate::version;
 use crate::DenoSubcommand;
 use deno_core::CoreIsolate;
+use deno_core::ModuleSpecifier;
 use deno_core::ZeroCopyBuf;
 use std::env;
 
 pub fn init(i: &mut CoreIsolate, s: &State) {
   i.register_op("op_start", s.stateful_json_op(op_start));
+  i.register_op("op_main_module", s.stateful_json_op(op_main_module));
   i.register_op("op_metrics", s.stateful_json_op(op_metrics));
 }
 
@@ -39,6 +41,21 @@ fn op_start(
   })))
 }
 
+fn op_main_module(
+  state: &State,
+  _args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<JsonOp, OpError> {
+  let main = &state.borrow().main_module.to_string();
+  let main_url = ModuleSpecifier::resolve_url_or_path(&main)?;
+  if main_url.as_url().scheme() == "file" {
+    let main_path = std::env::current_dir().unwrap().join(main_url.to_string());
+    state.check_read_blind(&main_path, "main_module")?;
+  }
+  state.check_unstable("Deno.mainModule");
+  Ok(JsonOp::Sync(json!(&main)))
+}
+
 fn op_metrics(
   state: &State,
   _args: Value,