Update tests for error regions and add a few new ones

flycheck-ert.el

@@ -99,7 +99,7 @@ Defaults to `error'."
 Like `with-temp-buffer', but resets the modification state of the
 temporary buffer to make sure that it is properly killed even if
 it has a backing file and is modified."
-  (declare (indent 0))
+  (declare (indent 0) (debug t))
   `(with-temp-buffer
      (unwind-protect
          ,(macroexp-progn body)
@@ -114,7 +114,7 @@ it has a backing file and is modified."
 
 BODY is evaluated with `current-buffer' being a buffer with the
 contents FILE-NAME."
-  (declare (indent 1))
+  (declare (indent 1) (debug t))
   `(let ((file-name ,file-name))
      (unless (file-exists-p file-name)
        (error "%s does not exist" file-name))
@@ -337,9 +337,10 @@ Raise an assertion error if the buffer is not clear afterwards."
 
 ERROR is a Flycheck error object."
   (let* ((overlay (-first (lambda (ov) (equal (overlay-get ov 'flycheck-error)
-                                              error))
+                                         error))
                           (flycheck-overlays-in 0 (+ 1 (buffer-size)))))
-         (region (flycheck-error-region-for-mode error 'symbols))
+         (flycheck-highlighting-mode 'symbols)
+         (region (flycheck-error-region error))
          (level (flycheck-error-level error))
          (category (flycheck-error-level-overlay-category level))
          (face (get category 'face))
@@ -436,8 +437,7 @@ resource directory."
 Return non-nil if the point is at the N'th Flycheck error in the
 current buffer.  Otherwise return nil."
   (let* ((error (nth (1- n) flycheck-current-errors))
-         (mode flycheck-highlighting-mode)
-         (region (flycheck-error-region-for-mode error mode)))
+         (region (flycheck-error-region error)))
     (and (member error (flycheck-overlay-errors-at (point)))
          (= (point) (car region)))))
 

test/flycheck-test.el

@@ -1280,6 +1280,26 @@
 
 
 ;;; Errors from syntax checks
+(defun flycheck-error-line-region (err)
+  (flycheck--line-region
+   (flycheck-error-start-line err)
+   (flycheck-error-end-line err)
+   (flycheck-error-buffer err)))
+
+(defun flycheck-error-column-region (err)
+  (-when-let* ((line (flycheck-error-start-line err))
+               (col (flycheck-error-start-column err))
+               (buf (flycheck-error-buffer err)))
+    (flycheck--column-region
+     (flycheck-line-column-to-position line col buf) buf)))
+
+(defun flycheck-error-thing-region (thing err)
+  (-when-let* ((line (flycheck-error-start-line err))
+               (col (flycheck-error-start-column err))
+               (buf (flycheck-error-buffer err)))
+    (flycheck-bounds-of-thing-at-pos
+     thing (flycheck-line-column-to-position line col buf) buf)))
+
 (ert-deftest flycheck-error-line-region ()
   :tags '(error-api)
   (flycheck-ert-with-temp-buffer
@@ -1333,6 +1353,10 @@
     ;; An incomplete expression
     (should-not (flycheck-error-thing-region 'sexp (flycheck-error-new-at 2 5)))))
 
+(defun flycheck-error-region-for-mode (err mode)
+  (let ((flycheck-highlighting-mode mode))
+    (flycheck-error-region err)))
+
 (ert-deftest flycheck-error-region-for-mode ()
   :tags '(error-api)
   (flycheck-ert-with-temp-buffer
@@ -1366,6 +1390,28 @@
     (should (= (flycheck-error-pos (flycheck-error-new-at 4 1)) 19))
     (should (= (flycheck-error-pos (flycheck-error-new-at 4 nil)) 19))))
 
+(ert-deftest flycheck-error-region ()
+  :tags '(error-api)
+  ;; All these tests should be independent of the ambient `flycheck-highlighting-mode'
+  (flycheck-ert-with-temp-buffer
+    (insert "    Hello\n   World\n")
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 1 1 1 3))
+                   '(1 . 3)))
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 1 4 1 6))
+                   '(4 . 6)))
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 1 nil 2 nil))
+                   '(5 . 19)))
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 2 4 nil 8))
+                   '(14 . 18)))
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 3 1 nil nil))
+                   '(19 . 20)))
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 4 1 12 15))
+                   '(19 . 20)))
+    (should (equal (flycheck-error-region (flycheck-error-new-with-coords 4 nil 5 nil))
+                   '(19 . 20)))))
+
+;; (ert-deftest flycheck-error-coords ()
+
 (ert-deftest flycheck-error-format-message-and-id/no-id ()
   :tags '(error-api)
   (should (string= (flycheck-error-format-message-and-id