Add .yas-setup.el for rjsx-mode

snippets/rjsx-mode/yas-setup.el

@@ -0,0 +1,20 @@
+;;; .yas-setup.el --- Yasnippet helper functions for JSX snippets
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'yasnippet)
+
+(defun yas-jsx-get-class-name-by-file-name ()
+  "Return name of class-like construct by `file-name'."
+  (if buffer-file-name
+      (let ((class-name (file-name-nondirectory
+                         (file-name-sans-extension buffer-file-name))))
+        (if (equal class-name "index")
+            (file-name-nondirectory
+             (directory-file-name (file-name-directory buffer-file-name)))
+          class-name))
+    ""))
+
+;;; .yas-setup.el ends here