add prettier support

Signed-off-by: Xe <me@christine.website>

common/home-manager/emacs/default.nix

@@ -440,6 +440,34 @@ in {
             '';
           };
 
+          add-node-modules-path = {
+            enable = true;
+            config = ''
+              (eval-after-load 'js2-mode
+                '(add-hook 'js2-mode-hook #'add-node-modules-path))
+              (eval-after-load 'typescript-mode
+                '(add-hook 'typescript-mode-hook #'add-node-modules-path))
+              (eval-after-load 'web-mode
+                '(add-hook 'web-mode-hook #'add-node-modules-path))
+            '';
+          };
+
+          prettier-js = {
+            enable = true;
+            after = [ "xe-tools" ];
+            config = ''
+              (add-hook 'js2-mode-hook 'prettier-js-mode)
+              (add-hook 'web-mode-hook 'prettier-js-mode)
+
+              (add-hook 'web-mode-hook #'(lambda ()
+                            (xe/enable-minor-mode
+                             '("\\.jsx?\\'" . prettier-js-mode))))
+              (add-hook 'web-mode-hook #'(lambda ()
+                            (xe/enable-minor-mode
+                             '("\\.tsx?\\'" . prettier-js-mode))))
+            '';
+          };
+
           deno-fmt = {
             enable = true;
             config = ''

common/home-manager/emacs/xe-tools.el

@@ -10,4 +10,10 @@
   (interactive)
   (insert "ಠ_ಠ"))
 
+(defun xe/enable-minor-mode (my-pair)
+  "Enable minor mode if filename match the regexp.  MY-PAIR is a cons cell (regexp . minor-mode)."
+  (if (buffer-file-name)
+      (if (string-match (car my-pair) buffer-file-name)
+          (funcall (cdr my-pair)))))
+
 (provide 'xe-tools)