Refactor allow_blank escape hatch to work better with params.

shard.yml

@@ -44,7 +44,8 @@ dependencies:
 development_dependencies:
   ameba:
     github: crystal-ameba/ameba
-    version: ~> 1.4
+    branch: master
+    # version: ~> 1.4
   lucky:
     github: luckyframework/lucky
     version: ">= 1.0.0"

spec/avram/operations/save_operation_spec.cr

@@ -83,13 +83,9 @@ private class SavePost < Post::SaveOperation
 end
 
 # This is to test an escape hatch where you don't want to
-# define a Nil type, but your field is optional
+# define a Nil type, but your String field can be an empty string
 private class AllowBlankComment < Comment::SaveOperation
-  skip_default_validations
-
-  before_save do
-    body.allow_blank = true
-  end
+  permit_columns body, post_id
 end
 
 module DefaultUserValidations
@@ -922,6 +918,15 @@ describe "Avram::SaveOperation" do
         comment.body.should eq("")
       end
     end
+    it "allows blank strings from params" do
+      post = PostFactory.create
+      params = build_params({comment: {post_id: post.id, body: ""}}.to_json, content_type: "application/json")
+      AllowBlankComment.create(params) do |op, new_comment|
+        op.valid?.should be_true
+        comment = new_comment.as(Comment)
+        comment.body.should eq("")
+      end
+    end
     it "still allows normal data to be saved" do
       post = PostFactory.create
       AllowBlankComment.create(post_id: post.id, body: "not blank") do |op, new_comment|
@@ -930,13 +935,21 @@ describe "Avram::SaveOperation" do
         comment.body.should eq("not blank")
       end
     end
-    it "fails at postgres when saving nil" do
+    it "fails at postgres when saving nil from named args" do
       post = PostFactory.create
       expect_raises(PQ::PQError) do
         AllowBlankComment.create(post_id: post.id) do |_op, _new_comment|
         end
       end
     end
+    it "fails at postgres when saving nil from params" do
+      post = PostFactory.create
+      params = build_params({comment: {post_id: post.id}}.to_json, content_type: "application/json")
+      expect_raises(PQ::PQError) do
+        AllowBlankComment.create(params) do |_op, _new_comment|
+        end
+      end
+    end
   end
 end
 

spec/support/models/comment.cr

@@ -4,7 +4,7 @@ class Comment < BaseModel
   table do
     primary_key custom_id : Int64
     timestamps
-    column body : String
+    column body : String, allow_blank: true
     belongs_to post : Post
   end
 end

src/avram/add_column_attributes.cr

@@ -56,7 +56,9 @@ module Avram::AddColumnAttributes
           name: :{{ attribute[:name].id }},
           param: permitted_params["{{ attribute[:name] }}"]?,
           value: value,
-          param_key: self.class.param_key)
+          param_key: self.class.param_key).tap do |attr|
+            attr.allow_blank = {{ attribute[:allow_blank] }}
+        end
       end
 
       private def default_value_for_{{ attribute[:name] }}
@@ -96,7 +98,7 @@ module Avram::AddColumnAttributes
       def set_{{ attribute[:name] }}_from_param(_value)
         # In nilable types, `nil` is ok, and non-nilable types we will get the
         # "is required" error.
-        if _value.blank?
+        if _value.blank? && !{{ attribute[:name] }}.allow_blank?
           {{ attribute[:name] }}.value = nil
           return
         end

src/avram/attribute.cr

@@ -19,6 +19,7 @@ class Avram::Attribute(T)
   def permitted
     @_permitted ||= begin
       Avram::PermittedAttribute(T).new(name: @name, param: @param, value: @value, param_key: @param_key).tap do |attribute|
+        attribute.allow_blank = allow_blank?
         errors.each do |error|
           attribute.add_error error
         end

src/avram/model.cr

@@ -243,7 +243,7 @@ abstract class Avram::Model
     {% end %}
   end
 
-  macro column(type_declaration, autogenerated = false, serialize is_serialized = false)
+  macro column(type_declaration, autogenerated = false, serialize is_serialized = false, allow_blank = false)
     {% if type_declaration.type.is_a?(Union) %}
       {% data_type = type_declaration.type.types.first %}
       {% nilable = true %}
@@ -257,7 +257,7 @@ abstract class Avram::Model
       {% value = nil %}
     {% end %}
 
-    {% COLUMNS << {name: type_declaration.var, type: data_type, nilable: nilable.id, autogenerated: autogenerated, value: value, serialized: is_serialized} %}
+    {% COLUMNS << {name: type_declaration.var, type: data_type, nilable: nilable.id, autogenerated: autogenerated, value: value, serialized: is_serialized, allow_blank: allow_blank} %}
   end
 
   macro setup_column_info_methods(columns, *args, **named_args)

src/avram/validations.cr

@@ -93,7 +93,7 @@ module Avram::Validations
   ) : Bool
     no_errors = true
     attributes.each do |attribute|
-      if attribute.value.blank_for_validates_required?
+      if attribute.value.blank_for_validates_required? && !attribute.allow_blank?
         attribute.add_error(message)
         no_errors = false
       end