fix: singularize resource names where appropriate (#197)

Closes #196.

Currently, `kele-resource` uses the plural form of the resource name,
e.g. `pods`, everywhere. This was done primarily out of convenience but
obviously is grammatically inaccurate in some places, e.g. "get a single
pods."

Here we introduce a mechanism for looking up the canonical singular form
of any given resource name from the discovery cache and apply it to the
`kele-resource` suffix labels.

docs/references/changelog.md

@@ -24,6 +24,8 @@ versioning][semver].
 - Fixed a bug where kubeconfig cluster entries with uppercase letters in the
   server address erroneously cause resource kind completion to silently fail and
   show no kinds present in cluster
+- Fixed a bug in `kele-resource` where the improper singular/plural form of the
+  resource name is used, e.g. "Get a single pods" instead of "Get a single pod"
 
 ### Changed
 

kele.el

@@ -342,6 +342,48 @@ If CONTEXT is nil, use the current context."
        (-map (-partial #'alist-get 'groupVersion))
        (-sort (lambda (a _) (equal a "v1")))))
 
+(defun kele--resource-list-has-resource (name resource-list)
+  "Return non-nil when RESOURCE-LIST has resource named NAME.
+
+RESOURCE-LIST expected to be an alist mirroring the
+APIResourceList schema."
+  (->> (alist-get 'resources resource-list)
+       (-any (lambda (resource)
+               (equal (alist-get 'name resource) name)))))
+
+(cl-defmethod kele--get-singular-for-plural ((cache kele--discovery-cache)
+                                             type
+                                             &key context)
+  "Look up the singular name for a given resource TYPE in CACHE.
+
+TYPE is expected to be the plural name of the resource.
+
+If CONTEXT is nil, use the current context."
+  (let* ((ctx (or context (kele-current-context-name)))
+         (resource-lists (kele--get-resource-lists-for-context cache ctx))
+
+         ;; TODO:
+         ;; - Accept group-version optional kwarg
+         ;; - Error if len(filtered-resource-lists) > 1 AND group-version not specified
+         ;; - Filter for group-version
+         (filtered-resource-lists (-filter (-partial #'kele--resource-list-has-resource type) resource-lists)))
+
+    (when (> (length filtered-resource-lists) 1)
+      (warn "More than one group-version found for resource name `%s'; assuming `%s'"
+            type
+            (alist-get 'groupVersion (car filtered-resource-lists))))
+
+    (let-alist (car filtered-resource-lists)
+      (let* ((resource (-first (lambda (resource)
+                                 (string-equal
+                                  (alist-get 'name resource)
+                                  type))
+                               .resources))
+             (lower (alist-get 'singularName resource)))
+        (if (or (not lower) (string-equal lower ""))
+            (downcase (alist-get 'kind resource))
+          lower)))))
+
 (cl-defmethod kele--resource-namespaced-p ((cache kele--discovery-cache)
                                            group-version
                                            type
@@ -1698,7 +1740,13 @@ instead of \"pod.\""
            :verb 'delete
            :resource .kind
            :context .context)
-          (format "Delete a single %s" (propertize .kind 'face 'warning))
+          (format "Delete a single %s" (propertize
+                                        (kele--get-singular-for-plural
+                                         kele--global-discovery-cache
+                                         .kind
+                                         :context .context)
+                                        'face
+                                        'warning))
         (format "Don't have permission to delete %s" .kind))))
   (interactive
    (-let* ((kind (kele--get-kind-arg))
@@ -1748,7 +1796,11 @@ instead of \"pod.\""
            :verb 'get
            :resource .kind
            :context .context)
-          (format "Get a single %s" (propertize .kind 'face 'warning))
+          (format "Get a single %s"
+                  (propertize
+                   (kele--get-singular-for-plural kele--global-discovery-cache .kind :context .context)
+                   'face
+                   'warning))
         (format "Don't have permission to get %s" .kind))))
   (interactive
    (-let* ((kind (kele--get-kind-arg))

tests/testdata/cache/discovery/123.456.789.0_9999/fake-group/v1/serverresources.json

@@ -4,7 +4,7 @@
             "kind": "AmbiguousThingFoo",
             "name": "ambiguousthings",
             "namespaced": true,
-            "singularName": "",
+            "singularName": "ambiguousthing",
             "verbs": [
                 "get"
             ]

tests/testdata/cache/discovery/123.456.789.0_9999/fake-other-group/v1/serverresources.json

@@ -4,7 +4,7 @@
             "kind": "AmbiguousThingBar",
             "name": "ambiguousthings",
             "namespaced": true,
-            "singularName": "",
+            "singularName": "ambiguousthing",
             "verbs": [
                 "get"
             ]

tests/unit/test-kele.el

@@ -336,6 +336,25 @@
     (it "sets the timer"
       (expect (oref cache timer) :to-equal :timer)))
 
+  (describe "kele--get-singular-for-plural"
+    (before-each
+      (setq kele-cache-dir (f-expand "./tests/testdata/cache"))
+      (async-wait (kele--cache-update kele--global-discovery-cache)))
+
+    (it "fetches singularName"
+      (expect
+       (kele--get-singular-for-plural kele--global-discovery-cache
+      "ambiguousthings")
+       :to-equal
+       "ambiguousthing"))
+
+    (describe "when singularName not present"
+      (it "returns lowercased .metadata.name"
+        (expect (kele--get-singular-for-plural kele--global-discovery-cache
+                                               "componentstatuses")
+                :to-equal
+                "componentstatus"))))
+
   (describe "kele--get-groupversions-for-type"
     (before-each
       (setq kele-cache-dir (f-expand "./tests/testdata/cache"))