(WIP) Test missing logging call linter

vex.toml

@@ -0,0 +1,8 @@
+[vex]
+version = "1"
+
+[files]
+ignore = [ "vex.toml", "vexes/", ".git/", ".gitignore", ".idea/", "lib/", "tests/", "venv/" ]
+
+[python]
+use-for = [ "*.star" ]

vexes/logging.star

@@ -0,0 +1,42 @@
+def init():
+    vex.observe('open_project', on_open_project)
+
+def find_logging_call(node):
+    for previous_sibling in node.previous_siblings():
+        if str(previous_sibling).startswith('logger.'):
+            return previous_sibling
+    return None
+
+def find_parent(node, predicate):
+    parent = node.parent().parent()
+    if predicate(parent):
+        return parent
+    return None
+
+def on_open_project(_):
+    vex.search(
+        'python',
+        '(return_statement) @return_statement',
+        on_match,
+    )
+
+def on_match(event):
+    return_statement = event.captures['return_statement']
+
+    parent = find_parent(
+        return_statement,
+        lambda node: node.kind == 'if_statement',
+    )
+
+    if type(parent) == type(None):
+        return
+
+    logging_call = find_logging_call(return_statement)
+    if logging_call:
+        return
+
+    vex.warn(
+        'logging',
+        'return statement without logging call',
+        at=(parent, 'consider adding the logging call')
+    )