test(prog-webdev): cover cj/webdev-format-buffer

I added `tests/test-prog-webdev-format.el` — 7 ERT tests over `cj/--webdev-format-command` (plain path, spaces-quoted, `.tsx`) and `cj/webdev-format-buffer` (prettier present → the region command targets `buffer-file-name`; the `file.ts` fallback when the buffer has no file; point clamps to `point-max` when the format shrinks the buffer; prettier missing → `user-error`). `executable-find` and `shell-command-on-region` are stubbed. `cj/webdev-keybindings` was already covered by `test-prog-webdev--format-wiring.el`.

1 files changed, 93 insertions, 0 deletions

diff --git a/tests/test-prog-webdev-format.el b/tests/test-prog-webdev-format.el
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+++ b/tests/test-prog-webdev-format.el
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+;;; test-prog-webdev-format.el --- Tests for the webdev prettier formatter -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Covers the prettier-formatting path in `modules/prog-webdev.el':
+;;   - `cj/--webdev-format-command'  (pure: file -> "prettier --stdin-filepath ...")
+;;   - `cj/webdev-format-buffer'     (interactive wrapper; `executable-find' and
+;;                                    `shell-command-on-region' stubbed)
+;;
+;; `cj/webdev-keybindings' (the C-; f mount) is already covered by
+;; `test-prog-webdev--format-wiring.el'.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(add-to-list 'load-path (expand-file-name "tests" user-emacs-directory))
+(require 'testutil-format-wiring)
+
+(format-test--ensure-packages-init)
+(require 'prog-webdev)
+
+;; --------------------------- cj/--webdev-format-command ----------------------
+
+(ert-deftest test-prog-webdev--format-command-normal ()
+  "Normal: a plain .ts path yields the stdin-filepath prettier command."
+  (should (equal "prettier --stdin-filepath /home/me/app.ts"
+                 (cj/--webdev-format-command "/home/me/app.ts"))))
+
+(ert-deftest test-prog-webdev--format-command-spaces-quoted ()
+  "Boundary: a path with spaces is shell-quoted."
+  (should (equal (format "prettier --stdin-filepath %s"
+                         (shell-quote-argument "/home/me/my app/index.tsx"))
+                 (cj/--webdev-format-command "/home/me/my app/index.tsx"))))
+
+(ert-deftest test-prog-webdev--format-command-tsx-extension ()
+  "Boundary: a .tsx path is passed through (prettier infers the parser)."
+  (should (equal "prettier --stdin-filepath /x/Component.tsx"
+                 (cj/--webdev-format-command "/x/Component.tsx"))))
+
+;; ---------------------------- cj/webdev-format-buffer ------------------------
+
+(ert-deftest test-prog-webdev-format-buffer-runs-prettier-on-the-file ()
+  "Normal: with prettier on PATH, the region command targets `buffer-file-name'."
+  (let (cmd)
+    (cl-letf (((symbol-function 'executable-find) (lambda (_p) "/usr/bin/prettier"))
+              ((symbol-function 'shell-command-on-region)
+               (lambda (_start _end command &rest _) (setq cmd command))))
+      (with-temp-buffer
+        (insert "const x=1\n")
+        (setq buffer-file-name "/home/me/app.ts")
+        (cj/webdev-format-buffer)
+        (setq buffer-file-name nil)))
+    (should (equal (cj/--webdev-format-command "/home/me/app.ts") cmd))))
+
+(ert-deftest test-prog-webdev-format-buffer-falls-back-to-file-ts ()
+  "Boundary: a buffer with no file uses the \"file.ts\" filename hint."
+  (let (cmd)
+    (cl-letf (((symbol-function 'executable-find) (lambda (_p) "/usr/bin/prettier"))
+              ((symbol-function 'shell-command-on-region)
+               (lambda (_start _end command &rest _) (setq cmd command))))
+      (with-temp-buffer
+        (insert "const x=1\n")
+        (should-not buffer-file-name)
+        (cj/webdev-format-buffer)))
+    (should (equal (cj/--webdev-format-command "file.ts") cmd))))
+
+(ert-deftest test-prog-webdev-format-buffer-clamps-point-to-point-max ()
+  "Boundary: after a format that shrinks the buffer, point clamps to point-max."
+  (cl-letf (((symbol-function 'executable-find) (lambda (_p) "/usr/bin/prettier"))
+            ((symbol-function 'shell-command-on-region)
+             (lambda (_start _end _command &rest _)
+               (delete-region (point-min) (point-max))
+               (insert "x"))))
+    (with-temp-buffer
+      (insert "a really long original buffer body that prettier will shorten\n")
+      (goto-char 40)
+      (cj/webdev-format-buffer)
+      (should (= (point) (point-max))))))
+
+(ert-deftest test-prog-webdev-format-buffer-errors-without-prettier ()
+  "Error: prettier missing -> `user-error', nothing shells out."
+  (let ((ran nil))
+    (cl-letf (((symbol-function 'executable-find) (lambda (_p) nil))
+              ((symbol-function 'shell-command-on-region)
+               (lambda (&rest _) (setq ran t))))
+      (with-temp-buffer
+        (should-error (cj/webdev-format-buffer) :type 'user-error)))
+    (should-not ran)))
+
+(provide 'test-prog-webdev-format)
+;;; test-prog-webdev-format.el ends here