Yasnippet minor mode working in lisp-interaction-mode but not in emacs-lisp-mode

Question

I wanted to test yasnippet for editing Emacs Lisp files. After installing it from the package manager, the problem is that it works fine from the *scratch* buffer but not when editing a Lisp file using emacs-lisp-mode.

To debug, I reduced my Emacs init file to one line:

(setq debug-on-error t)

Then I started Emacs from command line with:

$ emacs test.el

and run M-x yas-minor-mode and then M-x yas-reload-all, then I typed defun and pressed the TAB key, but nothing happend.

However, if I first switch to the *scratch* buffer and run the same commands it works fine and inserts the defun template when I press TAB..

Answer 1

The problem is that yasnippet doesn't define a "defun" snippet for emacs-lisp-mode. Instead, use the "def" snippet.

The reason you could use the "defun" snippet in the *scratch* buffer is because lisp-interaction-mode does have a "defun" snippet.
Look in the menu bar, under "YASnippet", you can find which snippets you can use.

To summarize: type def and press TAB.