feat: support Bool as param type

spec/params_spec.cr

@@ -22,6 +22,7 @@ module Prism::Params::Specs
       end
 
       type important : Array(String) | Null, validate: {size: (1..10)}
+      type boolean : Bool | Null?
     end
 
     @@last_params = uninitialized ParamsTuple
@@ -36,7 +37,7 @@ module Prism::Params::Specs
 
   describe SimpleAction do
     context "with valid params" do
-      response = handle_request(SimpleAction, Req.new(method: "GET", resource: "/?id=42&value=42&time=1526120573870&kebab-param=null&nest1[nest2][bar]=null&nest1[foo]=BAR&nest1[arrayParam][]=2&nest1[arrayParam][]=3&important[]=foo&important[]=42"))
+      response = handle_request(SimpleAction, Req.new(method: "GET", resource: "/?id=42&value=42&time=1526120573870&kebab-param=null&nest1[nest2][bar]=null&nest1[foo]=BAR&nest1[arrayParam][]=2&nest1[arrayParam][]=3&important[]=foo&important[]=42&boolean=true"))
 
       it "doesn't halt" do
         response.body.should eq "ok"
@@ -73,10 +74,14 @@ module Prism::Params::Specs
       it "has arrayParam in params" do
         SimpleAction.last_params[:important].should eq ["foo", "42"]
       end
+
+      it "has boolean in params" do
+        SimpleAction.last_params[:boolean].should eq true
+      end
     end
 
     context "with missing insignificant param" do
-      response = handle_request(SimpleAction, Req.new(method: "GET", resource: "/?id=42&important[]=foo&important[]=42"))
+      response = handle_request(SimpleAction, Req.new(method: "GET", resource: "/?id=42&important[]=foo&important[]=42&boolean=false"))
 
       it "doesn't halt" do
         response.body.should eq "ok"
@@ -85,6 +90,7 @@ module Prism::Params::Specs
       it "returns params" do
         SimpleAction.last_params[:id].should eq 42
         SimpleAction.last_params[:important].should eq ["foo", "42"]
+        SimpleAction.last_params[:boolean].should eq false
       end
     end
 
@@ -114,6 +120,12 @@ module Prism::Params::Specs
           response = handle_request(SimpleAction, Req.new(method: "GET", resource: "/?id=42&important[]=foo&nest1[arrayParam][]=foo"))
         end
       end
+
+      it "raises" do
+        expect_raises(InvalidParamTypeError) do
+          response = handle_request(SimpleAction, Req.new(method: "GET", resource: "/?id=42&important[]=foo&boolean=unknown"))
+        end
+      end
     end
 
     context "with invalid params" do
@@ -146,6 +158,7 @@ module Prism::Params::Specs
               arrayParam: [1, 2],
             },
             important: ["foo"],
+            boolean:   false,
           }.to_json,
           headers: HTTP::Headers{
             "Content-Type" => "application/json",
@@ -177,6 +190,10 @@ module Prism::Params::Specs
         it "has nested array params" do
           SimpleAction.last_params[:nest1]?.try &.[:array_param].should eq [2_u8, 4_u8]
         end
+
+        it "has boolean param" do
+          SimpleAction.last_params[:boolean].should eq false
+        end
       end
     end
   end

src/prism/ext/bool/from_param.cr

@@ -0,0 +1,16 @@
+struct Bool
+  # Initialize from *param*.
+  #
+  # The param value must be either `true`, `"true"`, `false` or `"false"`.
+  #
+  # ```
+  # Bool.from_param(<@value="true">) # => true
+  # ```
+  def self.from_param(param : Prism::Params::AbstractParam)
+    case param.value
+    when true, "true"   then true
+    when false, "false" then false
+    else                     raise Prism::Params::InvalidParamTypeError.new(param, "Bool")
+    end
+  end
+end

src/prism/ext/from_param.cr

@@ -2,6 +2,7 @@ require "../params/abstract_param"
 require "../params/errors"
 
 require "./array/from_param"
+require "./bool/from_param"
 require "./float/from_param"
 require "./int/from_param"
 require "./named_tuple/from_param"

src/prism/ext/union/from_param.cr

@@ -5,24 +5,15 @@ struct Union(T)
   #
   # NOTE: Types are iterated alphabetically, so `UInt8 | Null` would turn to `Null | UInt8`. That's why `Int32 | String` won't work, it will always return `String`.
   def self.from_param(param : Prism::Params::AbstractParam)
-    any = false
-    {% begin %}
-      result = (
-        {% for t in T %}
-          (
-            begin
-              x = {{ t.id }}.from_param(param)
-              any = true
-              x
-            rescue Exception
-              nil
-            end
-          ) ||
-        {% end %}
-        nil
-      )
-      raise Prism::Params::InvalidParamTypeError.new(param, {{@type.id.stringify}}) unless any
-      result.as(self)
-    {% end %}
+    result = (
+      {% for t in T %}
+        begin
+          return {{ t.id }}.from_param(param).as(self)
+        rescue Prism::Params::InvalidParamTypeError | ArgumentError
+        end
+      {% end %}
+    )
+
+    raise Prism::Params::InvalidParamTypeError.new(param, {{@type.id.stringify}})
   end
 end

src/prism/params/parsing.cr

@@ -194,7 +194,7 @@ module Prism::Params
                 raise InvalidParamTypeError.new(param.not_nil!, {{param[:type].stringify}})
               end
 
-              if json_value
+              if json_value != nil
                 {% if param[:parents] %}
                   params.deep_set({{param[:parents] + [param[:name]]}}, json_value)
                 {% else %}