Updating MemoryStore so it can support arrays. (#17)

* Updating MemoryStore so it can support arrays. Fixes #15

* Adding a small comment to describe why the array handling is different

Author: jwoertink

spec/stores/memory_store_spec.cr

@@ -73,6 +73,92 @@ describe LuckyCache::MemoryStore do
       friends.map(&.title).should contain("learn about cash")
     end
 
+    it "caches an array of strings" do
+      cache = LuckyCache::MemoryStore.new
+      counter = 0
+      cache.fetch("tags", as: Array(String)) do
+        counter += 1
+        ["foo", "bar", "baz"]
+      end
+      result = cache.fetch("tags", as: Array(String)) do
+        counter += 1
+        ["foo", "bar", "baz"]
+      end
+
+      result.should be_a(Array(String))
+      counter.should eq(1)
+      result.size.should eq(3)
+      result.should eq(["foo", "bar", "baz"])
+    end
+
+    it "caches an array of Int32" do
+      cache = LuckyCache::MemoryStore.new
+      counter = 0
+      cache.fetch("numbers", as: Array(Int32)) do
+        counter += 1
+        [1, 2, 3]
+      end
+      result = cache.fetch("numbers", as: Array(Int32)) do
+        counter += 1
+        [1, 2, 3]
+      end
+
+      result.should be_a(Array(Int32))
+      counter.should eq(1)
+      result.should eq([1, 2, 3])
+    end
+
+    it "caches an array of Int64" do
+      cache = LuckyCache::MemoryStore.new
+      counter = 0
+      cache.fetch("big_numbers", as: Array(Int64)) do
+        counter += 1
+        [100_i64, 200_i64]
+      end
+      result = cache.fetch("big_numbers", as: Array(Int64)) do
+        counter += 1
+        [100_i64, 200_i64]
+      end
+
+      result.should be_a(Array(Int64))
+      counter.should eq(1)
+      result.should eq([100_i64, 200_i64])
+    end
+
+    it "caches an array of Float64" do
+      cache = LuckyCache::MemoryStore.new
+      counter = 0
+      cache.fetch("scores", as: Array(Float64)) do
+        counter += 1
+        [1.5, 2.7, 3.9]
+      end
+      result = cache.fetch("scores", as: Array(Float64)) do
+        counter += 1
+        [1.5, 2.7, 3.9]
+      end
+
+      result.should be_a(Array(Float64))
+      counter.should eq(1)
+      result.should eq([1.5, 2.7, 3.9])
+    end
+
+    it "caches an array of Bool" do
+      cache = LuckyCache::MemoryStore.new
+      counter = 0
+      cache.fetch("flags", as: Array(Bool)) do
+        counter += 1
+        [true, false, true]
+      end
+      result = cache.fetch("flags", as: Array(Bool)) do
+        counter += 1
+        [true, false, true]
+      end
+
+      result.should be_a(Array(Bool))
+      counter.should eq(1)
+      result.should eq([true, false, true])
+    end
+
     it "caches basic types" do
       cache = LuckyCache::MemoryStore.new
       str = cache.fetch("string:key", as: String) { "test" }

src/lucky_cache/stores/memory_store.cr

@@ -18,7 +18,11 @@ module LuckyCache
     def write(key : CacheKey, *, expires_in : Time::Span = LuckyCache.settings.default_duration, &)
       data = yield
 
-      if data.is_a?(Array)
+      # This is because types like `String`, `Int32`, etc... don't include `Cacheable` like a custom type would.
+      # In order to support these, we have to account for them separately.
+      if data.is_a?(Array(String)) || data.is_a?(Array(Int32)) || data.is_a?(Array(Int64)) || data.is_a?(Array(Float64)) || data.is_a?(Array(Bool))
+        stored_data = data
+      elsif data.is_a?(Array)
         stored_data = [] of Cacheable
         data.each { |datum| stored_data << datum }
       else
@@ -49,7 +53,11 @@ module LuckyCache
     def fetch(key : CacheKey, *, as : Array(T).class, expires_in : Time::Span = LuckyCache.settings.default_duration, &) forall T
       if cache_item = read(key)
         new_array = Array(T).new
-        cache_item.value.as(Array(LuckyCache::Cacheable)).each { |v| new_array << v.as(T) }
+        {% if T < LuckyCache::Cacheable %}
+          cache_item.value.as(Array(LuckyCache::Cacheable)).each { |val| new_array << val.as(T) }
+        {% else %}
+          cache_item.value.as(Array(T)).each { |val| new_array << val }
+        {% end %}
         new_array
       else
         write(key, expires_in: expires_in) { yield }