feat(flymake): add Bandit backend for Python

modules/me-checkers.el

@@ -18,7 +18,33 @@
 
 (use-package flymake-quickdef
   :straight t
-  :autoload flymake-quickdef-backend)
+  :autoload flymake-quickdef-backend
+  :hook ((python-mode python-ts-mode) . +flymake-bandit-load)
+  :init
+  (defun +flymake-bandit-load ()
+    (add-hook 'flymake-diagnostic-functions #'flymake-check-bandit nil t))
+  :config
+  ;; Add Bandit support for Python (example from https://github.com/karlotness/flymake-quickdef)
+  (flymake-quickdef-backend flymake-bandit
+    :pre-let ((bandit-exec (executable-find "bandit")))
+    :pre-check (unless bandit-exec (error "Cannot find bandit executable"))
+    :write-type 'file
+    :proc-form (list bandit-exec "--format" "custom" "--msg-template" "diag:{line} {severity} {test_id}: {msg}" fmqd-temp-file)
+    :search-regexp "^diag:\\([[:digit:]]+\\) \\(HIGH\\|LOW\\|MEDIUM\\|UNDEFINED\\) \\([[:alpha:]][[:digit:]]+\\): \\(.*\\)$"
+    :prep-diagnostic
+    (let* ((lnum (string-to-number (match-string 1)))
+           (severity (match-string 2))
+           (code (match-string 3))
+           (text (match-string 4))
+           (pos (flymake-diag-region fmqd-source lnum))
+           (beg (car pos))
+           (end (cdr pos))
+           (type (cond
+                  ((string= severity "HIGH") :error)
+                  ((string= severity "MEDIUM") :warning)
+                  (t :note)))
+           (msg (format "%s (%s)" text code)))
+      (list fmqd-source beg end type msg))))
 
 
 (provide 'me-checkers)