Fix import map panics, use import map's location as its base URL (#2770)

cli/state.rs

@@ -200,14 +200,7 @@ impl ThreadSafeState {
 
     let import_map: Option<ImportMap> = match &flags.import_map_path {
       None => None,
-      Some(file_name) => {
-        let base_url = match &main_module {
-          Some(module_specifier) => module_specifier.clone(),
-          None => unreachable!(),
-        };
-        let import_map = ImportMap::load(&base_url.to_string(), file_name)?;
-        Some(import_map)
-      }
+      Some(file_path) => Some(ImportMap::load(file_path)?),
     };
 
     let mut seeded_rng = None;
@@ -380,3 +373,17 @@ fn thread_safe() {
     String::from("hello.js"),
   ]));
 }
+
+#[test]
+fn import_map_given_for_repl() {
+  let _result = ThreadSafeState::new(
+    flags::DenoFlags {
+      import_map_path: Some("import_map.json".to_string()),
+      ..flags::DenoFlags::default()
+    },
+    vec![String::from("./deno")],
+    ops::op_selector_std,
+    Progress::new(),
+    true,
+  );
+}