Make gravatar.el more configurable

For discussion, see the following thread:
https://lists.gnu.org/archive/html/emacs-devel/2019-07/msg00528.html

* etc/NEWS: Announce changes in gravatar.el user options.

* lisp/image/gravatar.el (gravatar-cache-ttl): Change :type to
number of seconds without changing the default value and while still
accepting other timestamp formats.
(gravatar-rating): Restrict :type to ratings recognized by Gravatar.
(gravatar-size): Allow nil as a value, in which case Gravatar's
default size is used.
(gravatar-default-image, gravatar-force-default): New user options
controlling the Gravatar query parameters 'default' and
'forcedefault', respectively.
(gravatar-base-url): Use HTTPS.
(gravatar--query-string): New helper function to facilitate testing.
(gravatar-build-url): Use it.

* test/lisp/image/gravatar-tests.el (gravatar-size)
(gravatar-default-image, gravatar-force-default)
(gravatar-build-url): New tests.

1 files changed, 38 insertions, 0 deletions

diff --git a/test/lisp/image/gravatar-tests.el b/test/lisp/image/gravatar-tests.el
index e6239da0084..bd61663f0e8 100644
--- a/test/lisp/image/gravatar-tests.el
+++ b/test/lisp/image/gravatar-tests.el
@@ -31,4 +31,42 @@
     (should (equal (gravatar-hash " foo") hash))
     (should (equal (gravatar-hash " foo ") hash))))
 
+(ert-deftest gravatar-size ()
+  "Test query strings for `gravatar-size'."
+  (let ((gravatar-default-image nil)
+        (gravatar-force-default nil))
+    (let ((gravatar-size 2048))
+      (should (equal (gravatar--query-string) "r=g&s=2048")))
+    (let ((gravatar-size nil))
+      (should (equal (gravatar--query-string) "r=g")))))
+
+(ert-deftest gravatar-default-image ()
+  "Test query strings for `gravatar-default-image'."
+  (let ((gravatar-force-default nil)
+        (gravatar-size nil))
+    (let ((gravatar-default-image nil))
+      (should (equal (gravatar--query-string) "r=g")))
+    (let ((gravatar-default-image "404"))
+      (should (equal (gravatar--query-string) "r=g&d=404")))
+    (let ((gravatar-default-image "https://foo/bar.png"))
+      (should (equal (gravatar--query-string)
+                     "r=g&d=https%3A%2F%2Ffoo%2Fbar.png")))))
+
+(ert-deftest gravatar-force-default ()
+  "Test query strings for `gravatar-force-default'."
+  (let ((gravatar-default-image nil)
+        (gravatar-size nil))
+    (let ((gravatar-force-default nil))
+      (should (equal (gravatar--query-string) "r=g")))
+    (let ((gravatar-force-default t))
+      (should (equal (gravatar--query-string) "r=g&f=y")))))
+
+(ert-deftest gravatar-build-url ()
+  "Test `gravatar-build-url'."
+  (let ((gravatar-default-image nil)
+        (gravatar-force-default nil)
+        (gravatar-size nil))
+    (should (equal (gravatar-build-url "foo") "\
+https://www.gravatar.com/avatar/acbd18db4cc2f85cedef654fccc4a4d8?r=g"))))
+
 ;;; gravatar-tests.el ends here