Better Request Parsing Parameters

Issue: #310

The framework should be able to parse JSON request body appropriately by
returning a `JSON::Any` object.

Currently, there is a bug when trying to parse JSON parameters from the
body of a request where nested JSON payload is not being parsed correctly

```crystal
{ "test": "test", "address": { "city": "New York" }
params["address"].as(Hash)["city"]
```
Params is now a custom Hash of the following signature
`Hash(String | Symbol, Amber::Router::ParamsType)` or
`Amber::Router::ParamsHash.new`

To give more context all parameters where being parsed using the
**HTTP::Params.parse** method which returns an object of type
**Hash(String, Array(String))** this caused issues when parsing
JSON params from the body, It turns out that nested JSON keys where
being parsed as a string. Basically, all `params` values are currently
returning as a string.

With the changes presented in this PR users can now define model objects
with JSON mapping that should be evaluated correctly based on the mapping
defined. So for instance:

```crystal
params["user_id"].as(Int64) => 123
params["address"].as(Hash).each ...
params["user"].as(User) => User.name
User.from_json(params["user"]) => User.name
```
**Controller**
The controller now generates the app using params.validation similar to
Rails strong params. It adds a method to the Controller and overloads the
Granite initializer and set_attributes methods.

```crystal
private def animal_params
  params.validation do
    required("name") { |v| v.str? & !v.empty? }
  end
end
animal = Animal.new(animal_params.validate!)
```

Model
Models generate for the Granite::ORM now includes the following line include
Amber::Models::Granite this will allow models to be populated with the controller
params using the params.validations. The reason this is added here and not to the
Granite::ORM repo is to keep Granite loosely coupled from any framework since the
params.validation is specific to amber.

```crystal
class Animal < Granite::ORM
  include Amber::Models::Granite
end
```

spec/amber/amber_spec.cr

@@ -4,8 +4,7 @@ struct UserSocket < Amber::WebSockets::ClientSocket; end
 
 struct RoomSocket < Amber::WebSockets::ClientSocket; end
 
-
-describe Amber do 
+describe Amber do
   describe ".env" do
     it "should return test" do
       Amber.env.test?.should be_truthy
@@ -54,9 +53,10 @@ describe Amber do
         settings.secret_key_base.should eq "mV6kTmG3k1yVFh-fPYpugSn0wbZveDvrvfQuv88DPF8"
       end
 
-      it "retains environment.yml settings that haven't been overwritten" do # NOTE: Any changes to settings here remain for all specs run afterwards.
-        # This is a problem.
-
+      it "retains environment.yml settings that haven't been overwritten" do
+        # NOTE: Any changes to settings here remain for all specs run afterwards.
+        # Added for convenience until settings is change to an instances
+        # instead of singleton this is still an "a problem".
         Amber::Server.configure do |server|
           server.name = "Hello World App"
           server.port = 8080

spec/amber/cli/commands/generator_spec.cr

@@ -6,14 +6,15 @@ module Amber::CLI
       context "scaffold" do
         it "generates and compile generated app" do
           ENV["AMBER_ENV"] = "test"
-
           MainCommand.run ["new", TESTING_APP]
           Dir.cd(TESTING_APP)
           MainCommand.run ["generate", "scaffold", "Animal", "name:string"]
           Amber::CLI::Spec.prepare_yaml(Dir.current)
+
           `shards build`
 
-          File.exists?("bin/#{TESTING_APP.split("/").last}").should be_true
+          File.exists?("bin/#{TEST_APP_NAME}").should be_true
+
           Amber::CLI::Spec.cleanup
         end
       end
@@ -49,6 +50,7 @@ module Amber::CLI
           File.read("./config/routes.cr").includes?(routes_get).should be_true
           File.read("./config/routes.cr").includes?(routes_delete).should be_true
           File.read("./src/controllers/animal_controller.cr").should eq output_class
+
           Amber::CLI::Spec.cleanup
         end
       end

spec/amber/router/context_spec.cr

@@ -2,7 +2,7 @@ require "../../../spec_helper"
 
 describe HTTP::Server::Context do
   describe "#override_request_method!" do
-    describe "when X-HTTP-Method-Overrid is present" do
+    context "when X-HTTP-Method-Override is present" do
       it "overrides form POST method to PUT, PATCH, DELETE" do
         %w(PUT PATCH DELETE).each do |method|
           header = HTTP::Headers.new
@@ -147,23 +147,24 @@ describe HTTP::Server::Context do
   it "parses json hash" do
     headers = HTTP::Headers.new
     headers["Content-Type"] = "application/json"
-    body = "{\"test\":\"test\"}"
+    body = %({ "test": "test", "address": { "city": "New York" }})
     request = HTTP::Request.new("POST", "/", headers, body)
 
     context = create_context(request)
 
     context.params["test"].should eq "test"
+    context.params["address"].as(Hash)["city"].should eq "New York"
   end
 
   it "parses json array" do
     headers = HTTP::Headers.new
     headers["Content-Type"] = "application/json"
-    body = "[\"test\",\"test2\"]"
+    body = %(["test", "test2"])
     request = HTTP::Request.new("POST", "/", headers, body)
 
     context = create_context(request)
 
-    context.params["_json"].should eq "[\"test\", \"test2\"]"
+    context.params["_json"].should eq %w(test test2)
   end
 
   it "parses files from multipart forms" do

spec/amber/validations/params_spec.cr

@@ -4,7 +4,7 @@ module Amber::Validators
   describe BaseRule do
     describe "#apply" do
       it "raises error when missing field" do
-        params = HTTP::Params.parse("")
+        params = params_builder("")
         rule = BaseRule.new("field", "") do
           false
         end
@@ -15,7 +15,7 @@ module Amber::Validators
       end
 
       it "returns true for given block" do
-        params = HTTP::Params.parse("field=val")
+        params = params_builder("field=val")
         rule = BaseRule.new("field", "") do
           true
         end
@@ -24,7 +24,7 @@ module Amber::Validators
       end
 
       it "returns false for the given block" do
-        params = HTTP::Params.parse("field=val")
+        params = params_builder("field=val")
         rule = BaseRule.new("field", "") do
           false
         end
@@ -35,7 +35,7 @@ module Amber::Validators
 
     describe "#error" do
       it "returns default error message" do
-        params = HTTP::Params.parse("field=val")
+        params = params_builder("field=val")
         error_message = "Field field is required"
         rule = BaseRule.new("field", nil) do
           false
@@ -47,7 +47,7 @@ module Amber::Validators
       end
 
       it "returns the given error message" do
-        params = HTTP::Params.parse("field=val")
+        params = params_builder("field=val")
         error_message = "You must provide this field"
         rule = BaseRule.new("field", error_message) do
           false
@@ -63,17 +63,17 @@ module Amber::Validators
   describe OptionalRule do
     describe "#apply" do
       it "does not apply rule when field is missing" do
-        params = HTTP::Params.parse("")
+        params = params_builder("")
         error_message = "You must provide this field"
         rule = OptionalRule.new("field", error_message) do
-          false
+          true
         end
 
         rule.apply(params).should be_true
       end
 
       it "applies rule when field is present" do
-        params = HTTP::Params.parse("field=val")
+        params = params_builder("field=val")
         error_message = "You must provide this field"
         rule = OptionalRule.new("field", error_message) do
           true
@@ -87,12 +87,12 @@ module Amber::Validators
   describe Params do
     describe "#validation" do
       it "validates required field" do
-        http_params = HTTP::Params.parse("name=elias&last_name=perez&middle=j")
+        http_params = params_builder("name=elias&last_name=perez&middle=j")
         validator = Validators::Params.new(http_params)
 
         result = validator.validation do
-          required(:name) { |v| v.str? & !v.empty? }
-          required("last_name") { |v| v.str? & !v.empty? }
+          required(:name) { |v| !v.nil? }
+          required("last_name") { |v| !v.nil? }
         end
 
         validator.valid?.should be_true
@@ -102,12 +102,12 @@ module Amber::Validators
       context "optional params" do
         context "when missing" do
           it "does not validate optional field" do
-            http_params = HTTP::Params.parse("last_name=&middle=j")
+            http_params = params_builder("last_name=&middle=j")
             validator = Validators::Params.new(http_params)
 
             result = validator.validation do
-              optional(:name) { |v| v.empty? }
-              required("last_name") { |v| v.empty? }
+              optional(:name) { |v| !v.nil? }
+              required("last_name") { |v| !v.nil? }
             end
 
             validator.valid?.should be_true
@@ -117,40 +117,58 @@ module Amber::Validators
 
         context "when present" do
           it "validates optional field" do
-            http_params = HTTP::Params.parse("name=")
+            http_params = params_builder("name=")
             validator = Validators::Params.new(http_params)
 
             result = validator.validation do
-              optional(:name) { |v| !v.empty? }
+              optional(:name) { |v| v.nil? }
             end
 
             validator.valid?.should be_false
             validator.errors.size.should eq 1
           end
         end
+
+        context "casting" do
+          it "returns false for the given block" do
+            params = params_builder("name=john&number=1&price=3.45&list=[1,2,3]")
+            validator = Validators::Params.new(params)
+            validator.validation do
+              required(:name) { |f| !f.to_s.empty? }
+              required(:number) { |f| f.as(String).to_i > 0 }
+              required(:price) { |f| f.as(String).to_f == 3.45 }
+              required(:list) do |f|
+                list = JSON.parse(f.as(String)).as_a
+                (list == [1, 2, 3] && !list.includes? 6)
+              end
+            end
+
+            validator.valid?.should be_truthy
+          end
+        end
       end
     end
 
     describe "#valid?" do
       it "returns false with invalid fields" do
-        http_params = HTTP::Params.parse("name=john&last_name=doe&middle=j")
+        http_params = params_builder("name=john&last_name=doe&middle=j")
         validator = Validators::Params.new(http_params)
 
         validator.validation do
-          required("name") { |v| v.empty? }
-          required("last_name") { |v| v.str? & !v.empty? }
+          required("name") { |v| v.nil? }
+          required("last_name") { |v| !v.nil? }
         end
 
         validator.valid?.should be_false
       end
 
       it "returns false when key does not exist" do
-        http_params = HTTP::Params.parse("name=elias")
+        http_params = params_builder("name=elias")
         validator = Validators::Params.new(http_params)
         result = {"nonexisting" => {nil, "Param [nonexisting] does not exist."}}
 
         validator.validation do
-          required("nonexisting") { |v| v.str? & !v.empty? }
+          required("nonexisting") { |v| !v.nil? }
         end
 
         expect_raises Exceptions::Validator::InvalidParam do
@@ -159,12 +177,12 @@ module Amber::Validators
       end
 
       it "returns true with valid fields" do
-        http_params = HTTP::Params.parse("name=elias&last_name=perez&middle=j")
+        http_params = params_builder("name=elias&last_name=perez&middle=j")
         validator = Validators::Params.new(http_params)
 
         validator.validation do
-          required("name") { |v| v.str? & !v.empty? }
-          required("last_name") { |v| v.str? & !v.empty? }
+          required("name") { |v| !v.nil? }
+          required("last_name") { |v| !v.nil? }
         end
 
         validator.valid?.should be_true
@@ -173,12 +191,12 @@ module Amber::Validators
 
     describe "#validate!" do
       it "raises error on failed validation" do
-        http_params = HTTP::Params.parse("name=elias&last_name=perez&middle=j")
+        http_params = params_builder("name=&last_name=&middle=j")
         validator = Validators::Params.new(http_params)
 
         validator.validation do
-          required("name") { |v| v.str? & v.empty? }
-          required("last_name") { |v| v.str? & !v.empty? }
+          required("name") { |v| !v.to_s.empty? }
+          required("last_name") { |v| !v.to_s.empty? }
         end
 
         expect_raises Exceptions::Validator::ValidationFailed do
@@ -187,17 +205,27 @@ module Amber::Validators
       end
 
       it "returns validated params on successful validation" do
-        http_params = HTTP::Params.parse("name=elias&last_name=perez&middle=j")
+        http_params = params_builder("name=elias&last_name=perez&middle=j")
         validator = Validators::Params.new(http_params)
         result : Hash(String, String) = {"name" => "elias", "last_name" => "perez"}
 
         validator.validation do
-          required("name") { |v| v.str? & !v.empty? }
-          required("last_name") { |v| v.str? & !v.empty? }
+          required("name") { |v| !v.nil? }
+          required("last_name") { |v| !v.nil? }
         end
 
         validator.validate!.should eq result
       end
     end
   end
 end
+
+def params_builder(body = "")
+  params = {} of String | Symbol => Amber::Router::ParamsType
+  return params if body.empty?
+
+  body.tr("?", "").split("&").each_with_object(params) do |item, params|
+    key, value = item.split("=")
+    params[key] = value
+  end
+end

spec/spec_helper.cr

@@ -1,12 +1,13 @@
 # NOTE: Constants should be set before require begins.
 
 ENV["AMBER_ENV"] = "test"
-TEST_PATH    = "spec/support/sample"
-PUBLIC_PATH  = TEST_PATH + "/public"
-VIEWS_PATH   = TEST_PATH + "/views"
-TESTING_APP  = "./tmp/test_app"
-APP_TPL_PATH = "./src/amber/cli/templates/app"
-CURRENT_DIR  = Dir.current
+TEST_PATH     = "spec/support/sample"
+PUBLIC_PATH   = TEST_PATH + "/public"
+VIEWS_PATH    = TEST_PATH + "/views"
+TEST_APP_NAME = "test_app"
+TESTING_APP   = "./tmp/#{TEST_APP_NAME}"
+APP_TPL_PATH  = "./src/amber/cli/templates/app"
+CURRENT_DIR   = Dir.current
 
 require "http"
 require "spec"

src/amber/cli/commands.cr

@@ -49,7 +49,7 @@ module Amber::CLI
       help desc: "# Describe available commands and usages"
       string ["-t", "--template"], desc: "# Preconfigure for selected template engine. Options: slang | ecr", default: "slang"
       string ["-d", "--database"], desc: "# Preconfigure for selected database. Options: pg | mysql | sqlite", default: "pg"
-      string ["-m", "--model"],    desc: "# Preconfigure for selected model. Options: granite | crecto", default: "granite"
+      string ["-m", "--model"], desc: "# Preconfigure for selected model. Options: granite | crecto", default: "granite"
     end
   end
 end

src/amber/cli/templates/auth.cr

@@ -25,7 +25,7 @@ module Amber::CLI
       @timestamp = Time.now.to_s("%Y%m%d%H%M%S")
       @primary_key = primary_key
       @visible_fields = @fields.reject(&.hidden).map(&.name)
-      
+
       add_routes :web, <<-ROUTES
         get "/signin", SessionController, :new
           post "/session", SessionController, :create
@@ -37,7 +37,7 @@ module Amber::CLI
       add_plugs :web, <<-PLUGS
         plug Authenticate.new
       PLUGS
-      
+
       add_dependencies <<-DEPENDENCY
       require "../src/models/**"
       require "../src/handlers/**"

src/amber/cli/templates/auth/src/controllers/registration_controller.cr.ecr

@@ -5,8 +5,8 @@ class RegistrationController < ApplicationController
   end
 
   def create
-    <%= @name %> = <%= @name.capitalize %>.new(params.to_h.select(<%= @visible_fields %>))
-    <%= @name %>.password = params["password"]
+    <%= @name %> = <%= @name.capitalize %>.new(registration_params.validate!)
+    <%= @name %>.password = params["password"].to_s
 
     if <%= @name %>.valid? && <%= @name %>.save
       session[:<%= @name %>_id] = <%= @name %>.id
@@ -17,4 +17,11 @@ class RegistrationController < ApplicationController
       render("new.<%= @language %>")
     end
   end
+
+  private def registration_params
+    params.validation do
+      required(:email) { |f| !f.nil? }
+      required(:password) { |f| !f.nil? }
+    end
+  end
 end