snap: add track 'latest' if no track is specified (#6835)

* snap: add track 'latest' if no track is specified

See https://snapcraft.io/docs/channels for more details.

* snap: assume track latest if channel does not specify it

changelogs/fragments/6835-snap-missing-track.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - snap - assume default track ``latest`` in parameter ``channel`` when not specified (https://github.com/ansible-collections/community.general/pull/6835, https://github.com/ansible-collections/community.general/issues/6821).

plugins/modules/snap.py

@@ -55,6 +55,9 @@ options:
             - Define which release of a snap is installed and tracked for updates.
               This option can only be specified if there is a single snap in the task.
             - If not passed, the C(snap) command will default to V(stable).
+            - If the value passed does not contain the C(track), it will default to C(latest).
+              For example, if V(edge) is passed, the module will assume the channel to be V(latest/edge).
+            - See U(https://snapcraft.io/docs/channels) for more details about snap channels.
         type: str
         required: false
     options:
@@ -277,7 +280,7 @@ class Snap(StateModuleHelper):
             match = [c for n, c in installed if n == name]
             if not match:
                 return Snap.NOT_INSTALLED
-            if channel and channel != match[0]:
+            if channel and match[0] not in (channel, "latest/{0}".format(channel)):
                 return Snap.CHANNEL_MISMATCH
             else:
                 return Snap.INSTALLED

tests/integration/targets/snap/tasks/test_channel.yml

@@ -44,3 +44,36 @@
       - install_microk8s_chan is changed
       - install_microk8s_chan_again is not changed
       - remove_microk8s is changed
+
+- name: Install package (shellcheck)
+  community.general.snap:
+    name: shellcheck
+    state: present
+  register: install_shellcheck
+
+- name: Install package with channel (shellcheck)
+  community.general.snap:
+    name: shellcheck
+    channel: edge
+    state: present
+  register: install_shellcheck_chan
+
+- name: Install package with channel (shellcheck) again
+  community.general.snap:
+    name: shellcheck
+    channel: edge
+    state: present
+  register: install_shellcheck_chan_again
+
+- name: Remove package (shellcheck)
+  community.general.snap:
+    name: shellcheck
+    state: absent
+  register: remove_shellcheck
+
+- assert:
+    that:
+      - install_shellcheck is changed
+      - install_shellcheck_chan is changed
+      - install_shellcheck_chan_again is not changed
+      - remove_shellcheck is changed