extend markdown-do to follow links

[edrex]

motivation: spacemacs and others bind <RET> to
markdown-do in evil normal mode.

with this change links can also be followed with enter.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves an existing feature)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the CONTRIBUTING.md document.
• I have updated the documentation in the README.md file if necessary.
• I have added an entry to CHANGES.md.
• I have added tests to cover my changes.
• All new and existing tests passed (using make test).

[syohex]

@edrex Your patch breaks tests and existed behaviors. How about following patch ?

diff --git a/markdown-mode.el b/markdown-mode.el
index 321a284..f999cfe 100644
--- a/markdown-mode.el
+++ b/markdown-mode.el
@@ -8221,9 +8221,6 @@ Jumps between reference links and definitions; between footnote
 markers and footnote text."
   (interactive)
   (cond
-   ;; Link
-   ((or (markdown-link-p) (markdown-wiki-link-p))
-    (markdown-follow-thing-at-point nil))
    ;; Footnote definition
    ((markdown-footnote-text-positions)
     (markdown-footnote-return))
@@ -8242,6 +8239,9 @@ markers and footnote text."
    ;; Align table
    ((markdown-table-at-point-p)
     (call-interactively #'markdown-table-align))
+   ;; Link
+   ((or (markdown-link-p) (markdown-wiki-link-p))
+    (markdown-follow-thing-at-point nil))
    ;; Otherwise
    (t
     (markdown-insert-gfm-checkbox))))

[edrex]

thanks for the quick feedback @syohex! I hadn't worked with the emacs testing tools yet, good time to start :)

I updated the change so the footnote jump test passes, putting the link branch between the footnote and table branches, since table cells can have inlines so links should take precedence there.

I added 3 failing tests that I don't yet know how to make asserts for, LMK if you have any ideas:

• check that a new buffer Foo.md is opened
• check that an external URL is launched in browser

Guessing some mock is needed at least for the URL

[syohex]

I fix your tests at #667. How about this ?