crystal-lang · Jul 11, 2016 · Jul 11, 2016
Showing with 66 additions and 5 deletions.

+7 −0 spec/std/class_spec.cr

+24 −0 spec/std/json/mapping_spec.cr

+7 −0 spec/std/yaml/mapping_spec.cr

+10 −0 src/class.cr

+1 −1 src/json/mapping.cr

+9 −0 src/union.cr

+6 −2 src/yaml/from_yaml.cr

+2 −2 src/yaml/mapping.cr
diff --git a/spec/std/class_spec.cr b/spec/std/class_spec.cr
@@ -30,4 +30,11 @@ describe Class do
   it "clones" do
     Int32.clone.should eq(Int32)
   end
+
+  it "#nilable" do
+    Int32.nilable?.should be_false
+    Nil.nilable?.should be_true
+    (Int32 | String).nilable?.should be_false
+    Int32?.nilable?.should be_true
+  end
 end
diff --git a/spec/std/json/mapping_spec.cr b/spec/std/json/mapping_spec.cr
@@ -140,6 +140,12 @@ class JSONWithNilableUnion
   })
 end
 
+class JSONWithNilableUnion2
+  JSON.mapping({
+    value: Int32?,
+  })
+end
+
 describe "JSON mapping" do
   it "parses person" do
     person = JSONPerson.from_json(%({"name": "John", "age": 30}))
@@ -402,5 +408,23 @@ describe "JSON mapping" do
     obj = JSONWithNilableUnion.from_json(%({"value": null}))
     obj.value.should be_nil
     obj.to_json.should eq(%({}))
+
+    obj = JSONWithNilableUnion.from_json(%({}))
+    obj.value.should be_nil
+    obj.to_json.should eq(%({}))
+  end
+
+  it "parses nilable union2" do
+    obj = JSONWithNilableUnion2.from_json(%({"value": 1}))
+    obj.value.should eq(1)
+    obj.to_json.should eq(%({"value":1}))
+
+    obj = JSONWithNilableUnion2.from_json(%({"value": null}))
+    obj.value.should be_nil
+    obj.to_json.should eq(%({}))
+
+    obj = JSONWithNilableUnion2.from_json(%({}))
+    obj.value.should be_nil
+    obj.to_json.should eq(%({}))
   end
 end
diff --git a/spec/std/yaml/mapping_spec.cr b/spec/std/yaml/mapping_spec.cr
@@ -48,6 +48,7 @@ class YAMLWithDefaults
     f: {type: Int32, nilable: true, default: 1},
     g: {type: Int32, nilable: true, default: nil},
     h: {type: Array(Int32), default: [1, 2, 3]},
+    i: String?,
   })
 end
 
@@ -214,6 +215,12 @@ describe "YAML mapping" do
       json.e.should eq false
       json = YAMLWithDefaults.from_yaml(%({"e":true}))
       json.e.should eq true
+
+      json = YAMLWithDefaults.from_yaml(%({}))
+      json.i.should be_nil
+
+      json = YAMLWithDefaults.from_yaml(%({"i":"bla"}))
+      json.i.should eq("bla")
     end
 
     it "create new array every time" do

diff --git a/src/class.cr b/src/class.cr
@@ -51,6 +51,16 @@ class Class
     typeof(t, u)
   end
 
+  # Returns `true` if this class is `Nil`.
+  #
+  # ```
+  # Int32.nilable? # => false
+  # Nil.nilable?   # => true
+  # ```
+  def nilable?
+    self == ::Nil
+  end
+
   def to_s(io)
     io << name
   end

diff --git a/src/json/mapping.cr b/src/json/mapping.cr
@@ -120,7 +120,7 @@ module JSON
 
       {% for key, value in properties %}
         {% unless value[:nilable] || value[:default] != nil %}
-          if %var{key.id}.is_a?(Nil) && !%found{key.id}
+          if %var{key.id}.is_a?(Nil) && !%found{key.id} && !Union({{value[:type]}}).nilable?
             raise JSON::ParseException.new("missing json attribute: {{(value[:key] || key).id}}", 0, 0)
           end
         {% end %}

diff --git a/src/union.cr b/src/union.cr
@@ -17,4 +17,13 @@
 # Union(Int32, Int32, Int32) # => Int32
 # ```
 struct Union
+  # Returns `true` if this union includes the `Nil` type.
+  #
+  # ```
+  # (Int32 | String).nilable? # => false
+  # (Int32 | Nil).nilable?    # => true
+  # ```
+  def self.nilable?
+    {{ T.any? &.==(::Nil) }}
+  end
 end
diff --git a/src/yaml/from_yaml.cr b/src/yaml/from_yaml.cr
@@ -19,8 +19,12 @@ def Array.from_yaml(string : String)
 end
 
 def Nil.new(pull : YAML::PullParser)
-  pull.read_scalar
-  nil
+  value = pull.read_scalar
+  if value.empty?
+    nil
+  else
+    raise YAML::ParseException.new("expected nil, not #{value}", 0, 0)
+  end
 end
 
 def Bool.new(pull : YAML::PullParser)

diff --git a/src/yaml/mapping.cr b/src/yaml/mapping.cr
@@ -121,7 +121,7 @@ module YAML
 
       {% for key, value in properties %}
         {% unless value[:nilable] || value[:default] != nil %}
-          if %var{key.id}.is_a?(Nil) && !%found{key.id}
+          if %var{key.id}.is_a?(Nil) && !%found{key.id} && !Union({{value[:type]}}).nilable?
             raise YAML::ParseException.new("missing yaml attribute: {{(value[:key] || key).id}}", 0, 0)
           end
         {% end %}
@@ -137,7 +137,7 @@ module YAML
         {% elsif value[:default] != nil %}
           @{{key.id}} = %var{key.id}.is_a?(Nil) ? {{value[:default]}} : %var{key.id}
         {% else %}
-          @{{key.id}} = %var{key.id}.not_nil!
+          @{{key.id}} = %var{key.id}.as({{value[:type]}})
         {% end %}
       {% end %}
     end