Auto-reload filetypes when filetypes.toml is saved

porcupine/plugins/filetypes.py

@@ -99,8 +99,6 @@ def load_filetypes() -> None:
         assert "filetype_name" not in filetype
         filetype["filetype_name"] = name
 
-
-def set_filedialog_kwargs() -> None:
     filedialog_kwargs["filetypes"] = [
         (
             name,
@@ -126,6 +124,7 @@ def get_filetype_from_matches(
     if not matches:
         return None
     if len(matches) >= 2:
+        # Last match, because it's more likely from the user's configuration rather than default.
         names = ", ".join(matches.keys())
         log.warning(
             f"{len(matches)} file types match {they_match_what}: {names}. The last match will be"
@@ -214,6 +213,8 @@ def apply_filetype_to_tab(filetype: FileType, tab: tabs.FileTab) -> None:
 
     with tab.settings.defer_change_events():
         # Reset all options whose values came from the previous filetype.
+        # This is needed because previous filetype could have set some option that
+        # the new filetype does not set.
         for name in tab.settings.get_options_by_tag("from_filetype"):
             tab.settings.reset(name)
 
@@ -228,10 +229,27 @@ def on_path_changed(tab: tabs.FileTab, junk: object = None) -> None:
     apply_filetype_to_tab(get_filetype_for_tab(tab), tab)
 
 
+def after_save(tab: tabs.FileTab, junk: object) -> None:
+    if tab.path == Path(dirs.user_config_dir) / "filetypes.toml":
+        # Reload all filetypes when the user saves filetypes.toml.
+        # If user has chosen a custom filetype, leave the tab alone.
+        tabs_with_default_filetype = [
+            tab
+            for tab in get_tab_manager().tabs()
+            if isinstance(tab, tabs.FileTab)
+            and tab.settings.get("filetype_name", str) == get_filetype_for_tab(tab)["filetype_name"]
+        ]
+        filetypes.clear()
+        load_filetypes()
+        for tab in tabs_with_default_filetype:
+            apply_filetype_to_tab(get_filetype_for_tab(tab), tab)
+
+
 def on_new_filetab(tab: tabs.FileTab) -> None:
     tab.settings.add_option("filetype_name", None, type_=Optional[str])
     on_path_changed(tab)
     tab.bind("<<PathChanged>>", partial(on_path_changed, tab), add=True)
+    tab.bind("<<AfterSave>>", partial(after_save, tab), add=True)
 
 
 def setup_argument_parser(parser: argparse.ArgumentParser) -> None:
@@ -263,7 +281,6 @@ def setup() -> None:
         "Default filetype for new files:",
         values=sorted(filetypes.keys(), key=str.casefold),
     )
-    set_filedialog_kwargs()
 
     for name in sorted(filetypes.keys(), key=str.casefold):
         escaped_name = name.replace("/", "//")  # doesn't work in all corner cases

tests/test_filetypes_plugin.py

@@ -6,8 +6,10 @@
 from tkinter import filedialog
 
 import pytest
+from pygments.lexer import LexerMeta
+from pygments.lexers import JsonLexer, RustLexer, TextLexer
 
-from porcupine import dirs, filedialog_kwargs, get_main_window
+from porcupine import dirs, filedialog_kwargs, get_main_window, menubar
 from porcupine.plugins import filetypes
 
 
@@ -34,13 +36,11 @@ def custom_filetypes():
     )
     filetypes.filetypes.clear()
     filetypes.load_filetypes()
-    filetypes.set_filedialog_kwargs()
 
     yield
     user_filetypes.unlink()
     filetypes.filetypes.clear()
     filetypes.load_filetypes()
-    filetypes.set_filedialog_kwargs()
 
 
 def test_filedialog_patterns_got_stripped():
@@ -125,6 +125,42 @@ def test_settings_reset_when_filetype_changes(filetab, tmp_path):
     assert len(filetab.settings.get("example_commands", object)) == 0
 
 
+@pytest.fixture
+def filetypes_toml_filetab(tabmanager):
+    tab = tabmanager.open_file(Path(dirs.user_config_dir) / "filetypes.toml")
+    yield tab
+    tabmanager.close_tab(tab)
+
+
+def test_saving_filetypes_toml_reloads_filetypes(
+    filetab, filetypes_toml_filetab, tabmanager, tmp_path
+):
+    filetypes_toml_filetab.textwidget.insert(
+        "end",
+        "[Foo]\nfilename_patterns = ['*.foo']\npygments_lexer = 'pygments.lexers.RustLexer'\n",
+    )
+    filetypes_toml_filetab.textwidget.edit_separator()
+    filetab.save_as(tmp_path / "asd.foo")
+    assert filetab.settings.get("pygments_lexer", LexerMeta) is TextLexer  # default
+
+    filetypes_toml_filetab.save()
+    tabmanager.update()
+    assert filetab.settings.get("pygments_lexer", LexerMeta) is RustLexer
+
+    filetypes_toml_filetab.textwidget.edit_undo()
+    filetypes_toml_filetab.save()
+    tabmanager.update()
+    assert filetab.settings.get("pygments_lexer", LexerMeta) is TextLexer
+
+    # If user sets custom filetype, respect that
+    tabmanager.select(filetab)
+    menubar.get_menu("Filetypes").invoke("JSON")
+    filetypes_toml_filetab.textwidget.edit_redo()
+    filetypes_toml_filetab.save()
+    tabmanager.update()
+    assert filetab.settings.get("pygments_lexer", LexerMeta) is JsonLexer
+
+
 def test_merging_settings():
     default = {
         "Plain Text": {"filename_patterns": ["*.txt"]},