yum always return changes dict, not only in check mode (#51987)

Previously the yum module would provide a `changes` dict when
executed in check mode but omit it when not in check mode in favor
of the `results` data which is raw output from the yum command. This
pull request makes that output uniform.

Fixes #51724

Signed-off-by: Adam Miller <admiller@redhat.com>

changelogs/fragments/yum-consistent-output-checkmode.yaml

@@ -0,0 +1,2 @@
+minor_changes:
+  - yum - provide consistent return data structure when run in check mode and not in check mode

lib/ansible/modules/packaging/os/yum.py

@@ -808,6 +808,8 @@ class YumModule(YumDnf):
 
         if self.module.check_mode:
             self.module.exit_json(changed=True, results=res['results'], changes=dict(installed=pkgs))
+        else:
+            res['changes'] = dict(installed=pkgs)
 
         lang_env = dict(LANG='C', LC_ALL='C', LC_MESSAGES='C')
         rc, out, err = self.module.run_command(cmd, environ_update=lang_env)
@@ -1043,6 +1045,8 @@ class YumModule(YumDnf):
         if pkgs:
             if self.module.check_mode:
                 self.module.exit_json(changed=True, results=res['results'], changes=dict(removed=pkgs))
+            else:
+                res['changes'] = dict(removed=pkgs)
 
             # run an actual yum transaction
             if self.autoremove:
@@ -1273,38 +1277,38 @@ class YumModule(YumDnf):
                     self.module.fail_json(**res)
 
         # check_mode output
-        if self.module.check_mode:
-            to_update = []
-            for w in will_update:
-                if w.startswith('@'):
-                    to_update.append((w, None))
-                elif w not in updates:
-                    other_pkg = will_update_from_other_package[w]
-                    to_update.append(
-                        (
-                            w,
-                            'because of (at least) %s-%s.%s from %s' % (
-                                other_pkg,
-                                updates[other_pkg]['version'],
-                                updates[other_pkg]['dist'],
-                                updates[other_pkg]['repo']
-                            )
+        to_update = []
+        for w in will_update:
+            if w.startswith('@'):
+                to_update.append((w, None))
+            elif w not in updates:
+                other_pkg = will_update_from_other_package[w]
+                to_update.append(
+                    (
+                        w,
+                        'because of (at least) %s-%s.%s from %s' % (
+                            other_pkg,
+                            updates[other_pkg]['version'],
+                            updates[other_pkg]['dist'],
+                            updates[other_pkg]['repo']
                         )
                     )
-                else:
-                    to_update.append((w, '%s.%s from %s' % (updates[w]['version'], updates[w]['dist'], updates[w]['repo'])))
-
-            if self.update_only:
-                res['changes'] = dict(installed=[], updated=to_update)
+                )
             else:
-                res['changes'] = dict(installed=pkgs['install'], updated=to_update)
+                to_update.append((w, '%s.%s from %s' % (updates[w]['version'], updates[w]['dist'], updates[w]['repo'])))
 
-            if will_update or pkgs['install']:
-                res['changed'] = True
+        if self.update_only:
+            res['changes'] = dict(installed=[], updated=to_update)
+        else:
+            res['changes'] = dict(installed=pkgs['install'], updated=to_update)
 
-            if obsoletes:
-                res['obsoletes'] = obsoletes
+        if obsoletes:
+            res['obsoletes'] = obsoletes
 
+        # return results before we actually execute stuff
+        if self.module.check_mode:
+            if will_update or pkgs['install']:
+                res['changed'] = True
             return res
 
         # run commands
@@ -1340,9 +1344,6 @@ class YumModule(YumDnf):
         if rc:
             res['failed'] = True
 
-        if obsoletes:
-            res['obsoletes'] = obsoletes
-
         return res
 
     def ensure(self, repoq):

test/integration/targets/yum/tasks/check_mode_consistency.yml

@@ -0,0 +1,61 @@
+- name: install htop in check mode to verify changes dict returned
+  yum:
+    name: htop
+    state: present
+  check_mode: yes
+  register: yum_changes_check_mode_result
+
+- name: install verify changes dict returned in check mode
+  assert:
+    that:
+      - "yum_changes_check_mode_result is success"
+      - "yum_changes_check_mode_result is changed"
+      - "'changes' in yum_changes_check_mode_result"
+      - "'installed' in yum_changes_check_mode_result['changes']"
+      - "'htop' in yum_changes_check_mode_result['changes']['installed']"
+
+- name: install htop to verify changes dict returned
+  yum:
+    name: htop
+    state: present
+  register: yum_changes_result
+
+- name: install verify changes dict returned
+  assert:
+    that:
+      - "yum_changes_result is success"
+      - "yum_changes_result is changed"
+      - "'changes' in yum_changes_result"
+      - "'installed' in yum_changes_result['changes']"
+      - "'htop' in yum_changes_result['changes']['installed']"
+
+- name: remove htop in check mode to verify changes dict returned
+  yum:
+    name: htop
+    state: absent
+  check_mode: yes
+  register: yum_changes_check_mode_result
+
+- name: remove verify changes dict returned in check mode
+  assert:
+    that:
+      - "yum_changes_check_mode_result is success"
+      - "yum_changes_check_mode_result is changed"
+      - "'changes' in yum_changes_check_mode_result"
+      - "'removed' in yum_changes_check_mode_result['changes']"
+      - "'htop' in yum_changes_check_mode_result['changes']['removed']"
+
+- name: remove htop to verify changes dict returned
+  yum:
+    name: htop
+    state: absent
+  register: yum_changes_result
+
+- name: remove verify changes dict returned
+  assert:
+    that:
+      - "yum_changes_result is success"
+      - "yum_changes_result is changed"
+      - "'changes' in yum_changes_result"
+      - "'removed' in yum_changes_result['changes']"
+      - "'htop' in yum_changes_result['changes']['removed']"

test/integration/targets/yum/tasks/main.yml

@@ -71,3 +71,7 @@
     - (ansible_distribution in ['RedHat', 'CentOS', 'ScientificLinux'] and ansible_distribution_major_version|int > 6)
 
 - include: 'proxy.yml'
+
+- include: 'check_mode_consistency.yml'
+  when:
+    - (ansible_distribution in ['RedHat', 'CentOS', 'ScientificLinux'] and ansible_distribution_major_version|int == 7)