branch: elpa/logview
commit 49cca08b84a6ef26f6ce701086eaa2b6483dce8f
Author: Paul Pogonyshev <pogonys...@gmail.com>
Commit: Paul Pogonyshev <pogonys...@gmail.com>
Handle errors in mode initialization in such a way as to never leave it in
half-initialized state (related to issue #55).
---
logview.el | 13 +++++++++++++
test/logview.el | 52 +++++++++++++++++++++++++++++++++++++++++++---------
2 files changed, 56 insertions(+), 9 deletions(-)
diff --git a/logview.el b/logview.el
index 61ffe64430..041b2a17ff 100644
--- a/logview.el
+++ b/logview.el
@@ -1212,6 +1212,19 @@ successfully.")
;;;###autoload
(define-derived-mode logview-mode nil "Logview"
"Major mode for viewing and filtering various log files."
+ (let (successful)
+ (unwind-protect
+ (progn (logview--set-up)
+ (setf successful t))
+ (unless successful
+ ;; Don't leave the mode half-initialized if there is any unhandled
error. This is
+ ;; not how Emacs normally works, but standard way is too confusing to
users and
+ ;; behavior depends on where exactly an error happened. Also, as
function
+ ;; `normal-mode' effectively eats the error (at least its backtrace),
debugging it
+ ;; is nearly impossible anyway.
+ (fundamental-mode)))))
+
+(defun logview--set-up ()
;; {LOCKED-NARROWING}
;; Logview is incompatible with locked narrowing of Emacs 29. Later
snapshots sort of
;; allow us to unlock this shit sometimes, but not the earlier, there we can
only set
diff --git a/test/logview.el b/test/logview.el
index aca79a6b65..b4eb08dadf 100644
--- a/test/logview.el
+++ b/test/logview.el
@@ -22,11 +22,32 @@
(require 'subr-x)
+(define-error 'logview-test-expected-error "Must be caught")
+
(defvar logview--test-directory (file-name-directory (or load-file-name
(buffer-file-name))))
(defvar inhibit-message)
+;; Copied from Eldev source code, see documentation there.
+(defmacro logview--advised (spec &rest body)
+ (declare (indent 1) (debug (sexp body)))
+ (let ((symbol (nth 0 spec))
+ (where (nth 1 spec))
+ (function (nth 2 spec))
+ (props (nthcdr 3 spec))
+ (fn (make-symbol "$fn")))
+ `(let ((,fn ,function))
+ (when ,fn
+ (if (advice-member-p ,fn ,symbol)
+ (setf ,fn nil)
+ (advice-add ,symbol ,where ,fn ,@props)))
+ (unwind-protect
+ ,(macroexp-progn body)
+ (when ,fn
+ (advice-remove ,symbol ,fn))))))
+
+
(defmacro logview--test-with-restriction (start end locking-label &rest body)
(declare (indent 3))
(if (fboundp 'with-restriction)
@@ -56,8 +77,22 @@
(should (string= (buffer-string) "foo bar baz")))))))
-(defun logview--test-display-warning-advice (&rest arguments)
- (error "Warning elevated to an error: %S" arguments))
+(ert-deftest logview-mode ()
+ (with-temp-buffer
+ (insert "2020-01-01 00:00:00 [thread 1] INFO hello - world\n")
+ (logview-mode)
+ (should (eq major-mode 'logview-mode))))
+
+
+(ert-deftest logview-mode-unsuccessful-setup ()
+ (condition-case nil
+ (logview--advised (#'logview--set-up :override (lambda () (signal
'logview-test-expected-error nil)))
+ (with-temp-buffer
+ (logview-mode)
+ ;; Errors during mode setup must not leave the mode half-initialized.
+ (should (eq major-mode 'fundamental-mode))))
+ (logview-test-expected-error)))
+
(defmacro logview--test-with-file (filename &rest body)
"Activate Logview in a temporary buffer with contents of the file.
@@ -86,13 +121,12 @@ buffer if the test needs that."
`(let (,@erase-customizations
,@extra-customizations
(inhibit-message t))
- (advice-add 'display-warning :override
#'logview--test-display-warning-advice)
- (unwind-protect
- (with-temp-buffer
- (insert-file-contents (expand-file-name ,filename
logview--test-directory))
- (,(or buffer-mode 'logview-mode))
- ,@body)
- (advice-remove 'display-warning
#'logview--test-display-warning-advice)))))
+ (logview--advised ('display-warning :override (lambda (&rest arguments)
+ (error "Warning
elevated to an error: %S" arguments)))
+ (with-temp-buffer
+ (insert-file-contents (expand-file-name ,filename
logview--test-directory))
+ (,(or buffer-mode 'logview-mode))
+ ,@body)))))
(defun logview--test-user-visible-buffer-string ()
