test(composite_kv): use named function captures in the shared suite (#259)

The shared `Nebulex.Cache.CompositeKVTest` passed literal anonymous
functions (`fn _ -> :pop end`, `&{&1, nil}`) to `get_and_update`. Those
functions belong to the in-memory test module, which doesn't exist on
peer nodes, so adapters that run the function on the node owning the
key (e.g., the Partitioned adapter) fail with `UndefinedFunctionError`.

Use captures of named helpers from the test cache instead, as the suite
already does for the other functions.

Author: cabol

test/shared/cache/composite_kv_test.exs

@@ -12,23 +12,23 @@ defmodule Nebulex.Cache.CompositeKVTest do
       test "stores a nil value when the function returns {get, nil}", %{cache: cache} do
         :ok = cache.put(:counter, 1)
 
-        assert cache.get_and_update(:counter, &{&1, nil}) == {:ok, {1, nil}}
+        assert cache.get_and_update(:counter, &cache.get_and_update_nil_fun/1) == {:ok, {1, nil}}
         assert cache.fetch!(:counter) == nil
         assert cache.has_key?(:counter) == {:ok, true}
       end
 
       test "pops the key when the function returns :pop", %{cache: cache} do
         :ok = cache.put(:counter, 1)
 
-        assert cache.get_and_update(:counter, fn _ -> :pop end) == {:ok, {1, nil}}
+        assert cache.get_and_update(:counter, &cache.pop_fun/1) == {:ok, {1, nil}}
         assert cache.has_key?(:counter) == {:ok, false}
-        assert cache.get_and_update(:counter, fn _ -> :pop end) == {:ok, {nil, nil}}
+        assert cache.get_and_update(:counter, &cache.pop_fun/1) == {:ok, {nil, nil}}
       end
 
       test "pops a cached nil value", %{cache: cache} do
         :ok = cache.put(:counter, nil)
 
-        assert cache.get_and_update(:counter, fn _ -> :pop end) == {:ok, {nil, nil}}
+        assert cache.get_and_update(:counter, &cache.pop_fun/1) == {:ok, {nil, nil}}
         assert cache.has_key?(:counter) == {:ok, false}
       end
 
@@ -52,8 +52,8 @@ defmodule Nebulex.Cache.CompositeKVTest do
       test "gets and updates the value", %{cache: cache} do
         assert cache.get_and_update!(:counter, &cache.get_and_update_fun/1) == {nil, 1}
         assert cache.get_and_update!(:counter, &cache.get_and_update_fun/1) == {1, 2}
-        assert cache.get_and_update!(:counter, fn _ -> :pop end) == {2, nil}
-        assert cache.get_and_update!(:counter, fn _ -> :pop end) == {nil, nil}
+        assert cache.get_and_update!(:counter, &cache.pop_fun/1) == {2, nil}
+        assert cache.get_and_update!(:counter, &cache.pop_fun/1) == {nil, nil}
       end
     end
 

test/support/test_cache.exs

@@ -11,6 +11,10 @@ defmodule Nebulex.TestCache do
 
         def get_and_update_bad_fun(_), do: :other
 
+        def get_and_update_nil_fun(current), do: {current, nil}
+
+        def pop_fun(_), do: :pop
+
         def fetch_or_store_fun, do: {:ok, "value"}
 
         def fetch_or_store_error_fun, do: {:error, :error}