Fix(kclvm-parser): return loading file failed error message from meth…

kclvm/parser/src/lib.rs

@@ -70,7 +70,14 @@ pub fn parse_file(filename: &str, code: Option<String>) -> Result<ast::Module, S
         let src = if let Some(s) = code {
             s
         } else {
-            std::fs::read_to_string(filename).unwrap()
+            match std::fs::read_to_string(filename) {
+                Ok(src) => src,
+                Err(_err) => {
+                    let err_msg =
+                        format!("Failed to load KCL file '{}'. Because '{}'", filename, _err);
+                    return Err(err_msg);
+                }
+            }
         };
 
         let sm = kclvm_span::SourceMap::new(FilePathMapping::empty());

kclvm/parser/src/parser/tests.rs

@@ -1,4 +1,5 @@
 use crate::lexer::parse_token_streams;
+use crate::parse_file;
 use crate::parser::Parser;
 use crate::session::ParseSession;
 use expect_test::{expect, Expect};
@@ -1266,3 +1267,15 @@ fn smoke_test_parsing_stmt() {
         assert_eq!(got, expect);
     });
 }
+
+#[test]
+fn test_parse_file_not_found() {
+    match parse_file("The file path is invalid", None) {
+        Ok(_) => {
+            panic!("unreachable")
+        }
+        Err(err_msg) => {
+            assert_eq!(err_msg, "Failed to load KCL file 'The file path is invalid'. Because 'No such file or directory (os error 2)'");
+        }
+    }
+}