refactor: use more specific exceptions for not found files

Author: gnikit

fortls/langserver.py

@@ -51,7 +51,11 @@
     load_intrinsics,
     set_lowercase_intrinsics,
 )
-from fortls.parsers.internal.parser import FortranFile, ParserError, get_line_context
+from fortls.parsers.internal.parser import (
+    FortranFile,
+    FortranFileNotFoundError,
+    get_line_context,
+)
 from fortls.parsers.internal.scope import Scope
 from fortls.parsers.internal.use import Use
 from fortls.parsers.internal.utilities import (
@@ -1396,7 +1400,7 @@ def update_workspace_file(
                     file_changed = file_obj.load_from_disk()
                     if not file_changed:
                         return False, None
-                except ParserError as exc:
+                except FortranFileNotFoundError as exc:
                     log.error("%s : %s", str(exc), filepath)
                     raise LSPError from exc
 
@@ -1459,7 +1463,7 @@ def file_init(
         # TODO: allow to bubble up the error message
         try:
             file_obj.load_from_disk()
-        except ParserError as e:
+        except FortranFileNotFoundError as e:
             return str(e)
         try:
             # On Windows multiprocess does not propagate global variables in a shell.

fortls/parsers/internal/parser.py

@@ -881,15 +881,16 @@ def load_from_disk(self) -> bool:
 
         Raises
         ------
-        FileReadDecodeError
-            If the file could not be read or decoded
+        FortranFileNotFoundError
+            If the file could not be found
         """
         contents: str
         try:
+            # errors="replace" prevents UnicodeDecodeError being raised
             with open(self.path, encoding="utf-8", errors="replace") as f:
                 contents = re.sub(r"\t", r" ", f.read())
-        except OSError as exc:
-            raise FileReadDecodeError("Could not read/decode file") from exc
+        except FileNotFoundError as exc:
+            raise FortranFileNotFoundError(exc) from exc
         # Check if files are the same
         try:
             hash = hashlib.md5(
@@ -2274,7 +2275,7 @@ def append_multiline_macro(def_value: str | tuple, line: str):
                         debug=debug,
                     )
                     log.debug("!!! Completed parsing include file")
-                except ParserError as e:
+                except FortranFileNotFoundError as e:
                     log.debug("!!! Failed to parse include file: %s", str(e))
             else:
                 log.debug(
@@ -2316,5 +2317,5 @@ class ParserError(Exception):
     """Parser base class exception"""
 
 
-class FileReadDecodeError(ParserError):
-    """File could not be read/decoded"""
+class FortranFileNotFoundError(ParserError, FileNotFoundError):
+    """File not found"""

test/test_parser.py

@@ -1,7 +1,7 @@
 import pytest
 from setup_tests import test_dir
 
-from fortls.parsers.internal.parser import FileReadDecodeError, FortranFile
+from fortls.parsers.internal.parser import FortranFile, FortranFileNotFoundError
 
 
 def test_line_continuations():
@@ -51,5 +51,5 @@ def test_end_scopes_semicolon():
 
 def test_load_from_disk_exception():
     file = FortranFile("/path/to/nonexistent/file.f90")
-    with pytest.raises(FileReadDecodeError):
+    with pytest.raises(FortranFileNotFoundError):
         file.load_from_disk()