greasemonkey: Add error handling

See #7245

1 files changed, 28 insertions, 11 deletions

diff --git a/qutebrowser/browser/greasemonkey.py b/qutebrowser/browser/greasemonkey.py
index 9ed2d691e..674ccaad1 100644
--- a/qutebrowser/browser/greasemonkey.py
+++ b/qutebrowser/browser/greasemonkey.py
@@ -233,6 +233,7 @@ class LoadResults:
     """The results of loading all Greasemonkey scripts."""
 
     successful: List[GreasemonkeyScript] = dataclasses.field(default_factory=list)
+    errors: List[Tuple[str, str]] = dataclasses.field(default_factory=list)
 
     def successful_str(self) -> str:
         if not self.successful:
@@ -241,6 +242,13 @@ class LoadResults:
         names = '\n'.join(str(script) for script in sorted(self.successful, key=str))
         return f"Loaded Greasemonkey scripts:\n\n{names}"
 
+    def error_str(self) -> Optional[str]:
+        if not self.errors:
+            return None
+
+        lines = '\n'.join(f"{script}: {error}" for script, error in sorted(self.errors))
+        return f"Greasemonkey scripts failed to load:\n\n{lines}"
+
 
 class GreasemonkeyMatcher:
 
@@ -314,24 +322,26 @@ class GreasemonkeyManager(QObject):
         self._run_end = []
         self._run_idle = []
 
-        scripts = []
+        successful = []
+        errors = []
         for scripts_dir in _scripts_dirs():
             scripts_dir = os.path.abspath(scripts_dir)
             log.greasemonkey.debug("Reading scripts from: {}".format(scripts_dir))
 
             for script_filename in glob.glob(os.path.join(scripts_dir, '*.js')):
-                if not os.path.isfile(script_filename):
-                    continue
                 script_path = os.path.join(scripts_dir, script_filename)
-                with open(script_path, encoding='utf-8-sig') as script_file:
-                    script = GreasemonkeyScript.parse(script_file.read(),
-                                                      script_filename)
-                    assert script.name, script
-                    self.add_script(script, force)
-                    scripts.append(script)
+                try:
+                    with open(script_path, encoding='utf-8-sig') as script_file:
+                        script = GreasemonkeyScript.parse(
+                            script_file.read(), script_filename)
+                        assert script.name, script
+                        self.add_script(script, force)
+                        successful.append(script)
+                except OSError as e:
+                    errors.append((os.path.basename(script_filename), str(e)))
 
         self.scripts_reloaded.emit()
-        return LoadResults(successful=scripts)
+        return LoadResults(successful=successful, errors=errors)
 
     def add_script(self, script, force=False):
         """Add a GreasemonkeyScript to this manager.
@@ -477,12 +487,19 @@ def greasemonkey_reload(force: bool = False, quiet: bool = False) -> None:
     if not quiet:
         message.info(result.successful_str())
 
+    errors = result.error_str()
+    if errors is not None:
+        message.error(errors)
+
 
 def init():
     """Initialize Greasemonkey support."""
     global gm_manager
     gm_manager = GreasemonkeyManager()
-    gm_manager.load_scripts()
+    result = gm_manager.load_scripts()
+    errors = result.error_str()
+    if errors is not None:
+        message.error(errors)
 
     for scripts_dir in _scripts_dirs():
         try: