Add helpers in Lookup and return a Maybe from lookup. (#84)

test/HTTPure/HeadersSpec.purs

@@ -3,6 +3,7 @@ module HTTPure.HeadersSpec where
 import Prelude
 
 import Control.Monad.Eff.Class as EffClass
+import Data.Maybe as Maybe
 import Data.Tuple as Tuple
 import Test.Spec as Spec
 
@@ -16,14 +17,14 @@ lookupSpec :: SpecHelpers.Test
 lookupSpec = Spec.describe "lookup" do
   Spec.describe "when the string is in the header set" do
     Spec.describe "when searching with lowercase" do
-      Spec.it "is the string" do
-        Headers.header "x-test" "test" !! "x-test" ?= "test"
+      Spec.it "is Just the string" do
+        Headers.header "x-test" "test" !! "x-test" ?= Maybe.Just "test"
     Spec.describe "when searching with uppercase" do
-      Spec.it "is the string" do
-        Headers.header "x-test" "test" !! "X-Test" ?= "test"
+      Spec.it "is Just the string" do
+        Headers.header "x-test" "test" !! "X-Test" ?= Maybe.Just "test"
   Spec.describe "when the string is not in the header set" do
-    Spec.it "is an empty string" do
-      Headers.empty !!  "X-Test" ?= ""
+    Spec.it "is Nothing" do
+      ((Headers.empty !! "X-Test") :: Maybe.Maybe String) ?= Maybe.Nothing
 
 showSpec :: SpecHelpers.Test
 showSpec = Spec.describe "show" do

test/HTTPure/LookupSpec.purs

@@ -2,36 +2,57 @@ module HTTPure.LookupSpec where
 
 import Prelude
 
+import Data.Maybe as Maybe
 import Data.StrMap as StrMap
 
 import Test.Spec as Spec
 
-import HTTPure.Lookup ((!!))
+import HTTPure.Lookup ((!!), (!@), (!?))
 
 import HTTPure.SpecHelpers as SpecHelpers
 import HTTPure.SpecHelpers ((?=))
 
+atSpec :: SpecHelpers.Test
+atSpec = Spec.describe "at" do
+  Spec.describe "when the lookup returns a Just" do
+    Spec.it "is the value inside the Just" do
+      [ "one", "two", "three" ] !@ 1 ?= "two"
+  Spec.describe "when the lookup returns a Nothing" do
+    Spec.it "is mempty" do
+      [ "one", "two", "three" ] !@ 4 ?= ""
+
+hasSpec :: SpecHelpers.Test
+hasSpec = Spec.describe "has" do
+  Spec.describe "when the lookup returns a Just" do
+    Spec.it "is true" do
+      [ "one", "two", "three" ] !? 1 ?= true
+  Spec.describe "when the lookup returns a Nothing" do
+    Spec.it "is false" do
+      [ "one", "two", "three" ] !? 4 ?= false
+
 lookupArraySpec :: SpecHelpers.Test
 lookupArraySpec = Spec.describe "lookupArray" do
   Spec.describe "when the index is in bounds" do
-    Spec.it "is the segment at the index" do
-      [ "one", "two", "three" ] !! 1 ?= "two"
+    Spec.it "is Just the value at the index" do
+      [ "one", "two", "three" ] !! 1 ?= Maybe.Just "two"
   Spec.describe "when the index is out of bounds" do
-    Spec.it "is an empty monoid" do
-      [ "one", "two", "three" ] !! 4 ?= ""
+    Spec.it "is Nothing" do
+      (([ "one", "two", "three" ] !! 4) :: Maybe.Maybe String) ?= Maybe.Nothing
 
 lookupStrMapSpec :: SpecHelpers.Test
 lookupStrMapSpec = Spec.describe "lookupStrMap" do
   Spec.describe "when the key is in the StrMap" do
-    Spec.it "is the value at the given key" do
-      mockStrMap !! "foo" ?= "bar"
+    Spec.it "is Just the value at the given key" do
+      mockStrMap !! "foo" ?= Maybe.Just "bar"
   Spec.describe "when the key is not in the StrMap" do
-    Spec.it "is an empty monoid" do
-      mockStrMap !! "baz" ?= ""
+    Spec.it "is Nothing" do
+      ((mockStrMap !! "baz") :: Maybe.Maybe String) ?= Maybe.Nothing
   where
     mockStrMap = StrMap.singleton "foo" "bar"
 
 lookupSpec :: SpecHelpers.Test
 lookupSpec = Spec.describe "Lookup" do
+  atSpec
+  hasSpec
   lookupArraySpec
   lookupStrMapSpec