From 367c8d64516f9a2baf8986b79e8cb7e1a0b2cb43 Mon Sep 17 00:00:00 2001
From: VeljkoMaksimovic <maxi.maksimovic7@gmail.com>
Date: Tue, 11 Oct 2022 10:26:58 +0200
Subject: [PATCH 1/2] Pass key to fallback function

---
 lib/cacheman.ex        |  2 +-
 test/cacheman_test.exs | 16 +++++++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/lib/cacheman.ex b/lib/cacheman.ex
index 3495e8c..402ae36 100644
--- a/lib/cacheman.ex
+++ b/lib/cacheman.ex
@@ -190,7 +190,7 @@ defmodule Cacheman do
   def fetch(name, key, put_opts, fallback) do
     case get(name, key) do
       {:ok, nil} ->
-        case fallback.() do
+        case fallback.(key) do
           {:ok, value} ->
             put(name, key, value, put_opts)
             {:ok, value}
diff --git a/test/cacheman_test.exs b/test/cacheman_test.exs
index 4016bca..ea45d5a 100644
--- a/test/cacheman_test.exs
+++ b/test/cacheman_test.exs
@@ -88,7 +88,11 @@ defmodule CachemanTest do
       assert {:ok, nil} = Cacheman.get(:good, key)
 
       # if we fetch on empty value, the fallback function is executed
-      assert {:ok, "hello"} = Cacheman.fetch(:good, key, fn -> {:ok, "hello"} end)
+      assert {:ok, "hello"} =
+               Cacheman.fetch(:good, key, fn passed_key ->
+                 assert passed_key == key
+                 {:ok, "hello"}
+               end)
 
       # the value of the fallback is saved into the cache
       assert {:ok, "hello"} = Cacheman.get(:good, key)
@@ -182,11 +186,17 @@ defmodule CachemanTest do
       key = "test-#{:rand.uniform(10_000)}"
 
       assert {:ok, nil} = Cacheman.get(:broken, key)
-      assert {:ok, "hello"} = Cacheman.fetch(:broken, key, fn -> {:ok, "hello"} end)
+
+      assert {:ok, "hello"} =
+               Cacheman.fetch(:broken, key, fn passed_key ->
+                 assert passed_key == key
+                 {:ok, "hello"}
+               end)
+
       assert {:ok, nil} = Cacheman.get(:broken, key)
 
       assert {:ok, "this-is-not-used"} =
-               Cacheman.fetch(:broken, key, fn -> {:ok, "this-is-not-used"} end)
+               Cacheman.fetch(:broken, key, fn _ -> {:ok, "this-is-not-used"} end)
     end
 
     test "TTL for keys" do

From 6c0737e44bc93447f223ad00bdd9ae9637f3ec82 Mon Sep 17 00:00:00 2001
From: VeljkoMaksimovic <maxi.maksimovic7@gmail.com>
Date: Tue, 11 Oct 2022 13:27:21 +0200
Subject: [PATCH 2/2] Check fallback arity

---
 lib/cacheman.ex        | 2 +-
 test/cacheman_test.exs | 6 +-----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/lib/cacheman.ex b/lib/cacheman.ex
index 402ae36..d08817e 100644
--- a/lib/cacheman.ex
+++ b/lib/cacheman.ex
@@ -190,7 +190,7 @@ defmodule Cacheman do
   def fetch(name, key, put_opts, fallback) do
     case get(name, key) do
       {:ok, nil} ->
-        case fallback.(key) do
+        case if is_function(fallback, 0), do: fallback.(), else: fallback.(key) do
           {:ok, value} ->
             put(name, key, value, put_opts)
             {:ok, value}
diff --git a/test/cacheman_test.exs b/test/cacheman_test.exs
index ea45d5a..5f7ff00 100644
--- a/test/cacheman_test.exs
+++ b/test/cacheman_test.exs
@@ -88,11 +88,7 @@ defmodule CachemanTest do
       assert {:ok, nil} = Cacheman.get(:good, key)
 
       # if we fetch on empty value, the fallback function is executed
-      assert {:ok, "hello"} =
-               Cacheman.fetch(:good, key, fn passed_key ->
-                 assert passed_key == key
-                 {:ok, "hello"}
-               end)
+      assert {:ok, "hello"} = Cacheman.fetch(:good, key, fn -> {:ok, "hello"} end)
 
       # the value of the fallback is saved into the cache
       assert {:ok, "hello"} = Cacheman.get(:good, key)