Fix api url_matches and servers validations not applying on updates.

Since we're using the Rails nested attributes stuff, when items are
removed, they're only marked for deletion, which means the validations
still think they exist. We have to explicitly look at each record to see
if it's marked for deletion to really determine whether any url matches
or servers will still exist after saving.

Fixes 18F/api.data.gov#215

app/assets/javascripts/admin/templates/apis/_form.hbs

@@ -15,7 +15,7 @@
       optionValuePath='content.id'
       optionLabelPath='content.name'}}
 
-    <table class="table table-striped table-condensed">
+    <table id="servers_table" class="table table-striped table-condensed">
       <thead>
         <tr>
           <th>{{t 'admin.api.servers.server'}}</th>

app/assets/javascripts/admin/templates/apis/url_matches.hbs

@@ -1,5 +1,5 @@
 <div id="url_matches">
-  <table id="url_matches" class="table table-striped table-condensed">
+  <table id="url_matches_table" class="table table-striped table-condensed">
     <thead>
       <tr>
         <th>Frontend Prefix</th>

app/models/api.rb

@@ -47,7 +47,7 @@ class Api
   validates :balance_algorithm,
     :inclusion => { :in => %w(round_robin least_conn ip_hash) }
   validates_each :servers, :url_matches do |record, attr, value|
-    if(value.blank?)
+    if(value.blank? || (value && value.reject(&:marked_for_destruction?).blank?))
       record.errors.add(:base, "must have at least one #{attr}")
     end
   end

spec/controllers/api/v1/apis_controller_spec.rb

@@ -64,6 +64,97 @@
     @empty_url_prefixes_api.save!(:validate => false)
   end
 
+  shared_examples "validates nested attributes presence - create" do |field|
+    it "returns a validation error if #{field} is set to nil" do
+      admin_token_auth(@admin)
+      attributes = FactoryGirl.attributes_for(:api, {
+        field => nil,
+      })
+
+      expect do
+        post :create, :format => "json", :api => attributes
+        response.status.should eql(422)
+        data = MultiJson.load(response.body)
+        data.keys.should eql(["errors"])
+        data["errors"].should eql({
+          "base" => ["must have at least one #{field}"],
+        })
+      end.to_not change { Api.count }
+    end
+
+    it "returns a validation error if #{field} is set to an empty array" do
+      admin_token_auth(@admin)
+      attributes = FactoryGirl.attributes_for(:api, {
+        field => [],
+      })
+
+      expect do
+        post :create, :format => "json", :api => attributes
+        response.status.should eql(422)
+        data = MultiJson.load(response.body)
+        data.keys.should eql(["errors"])
+        data["errors"].should eql({
+          "base" => ["must have at least one #{field}"],
+        })
+      end.to_not change { Api.count }
+    end
+
+    it "accepts the input if at least one url prefix exists" do
+      admin_token_auth(@admin)
+      attributes = FactoryGirl.attributes_for(:api, {
+        field => [FactoryGirl.attributes_for(:"api_#{field.to_s.singularize}")],
+      })
+
+      expect do
+        post :create, :format => "json", :api => attributes
+        response.status.should eql(201)
+        data = MultiJson.load(response.body)
+        data["api"]["name"].should eql(attributes[:name])
+      end.to change { Api.count }.by(1)
+    end
+  end
+
+  shared_examples "validates nested attributes presence - update" do |field|
+    it "returns a validation error if #{field} is set to nil" do
+      admin_token_auth(@admin)
+      attributes = @api.serializable_hash
+      attributes[field.to_s] = nil
+
+      put :update, :format => "json", :id => @api.id, :api => attributes
+      response.status.should eql(422)
+      data = MultiJson.load(response.body)
+      data.keys.should eql(["errors"])
+      data["errors"].should eql({
+        "base" => ["must have at least one #{field}"],
+      })
+    end
+
+    it "returns a validation error if #{field} is set to an empty array" do
+      admin_token_auth(@admin)
+      attributes = @api.serializable_hash
+      attributes[field.to_s] = []
+
+      put :update, :format => "json", :id => @api.id, :api => attributes
+      response.status.should eql(422)
+      data = MultiJson.load(response.body)
+      data.keys.should eql(["errors"])
+      data["errors"].should eql({
+        "base" => ["must have at least one #{field}"],
+      })
+    end
+
+    it "accepts the input if at least one #{field} exists" do
+      admin_token_auth(@admin)
+      attributes = @api.serializable_hash
+      attributes[field.to_s] = [FactoryGirl.attributes_for(:"api_#{field.to_s.singularize}")]
+
+      put :update, :format => "json", :id => @api.id, :api => attributes
+      response.status.should eql(204)
+      @api = Api.find(@api.id)
+      @api[field].length.should eql(1)
+    end
+  end
+
   shared_examples "api settings header fields - show" do |field|
     it "returns no headers as an empty string" do
       api = FactoryGirl.create(:api, {
@@ -229,7 +320,6 @@
         api.settings.send(field).length.should eql(1)
       end.to change { Api.count }.by(1)
     end
-
   end
 
   shared_examples "api settings header fields - update" do |field|
@@ -758,6 +848,14 @@
       end
     end
 
+    describe "servers" do
+      it_behaves_like "validates nested attributes presence - create", :servers
+    end
+
+    describe "matching url prefixes" do
+      it_behaves_like "validates nested attributes presence - create", :url_matches
+    end
+
     describe "request headers" do
       it_behaves_like "api settings header fields - create", :headers
     end
@@ -1035,6 +1133,14 @@
       end
     end
 
+    describe "servers" do
+      it_behaves_like "validates nested attributes presence - update", :servers
+    end
+
+    describe "matching url prefixes" do
+      it_behaves_like "validates nested attributes presence - update", :url_matches
+    end
+
     describe "request headers" do
       it_behaves_like "api settings header fields - update", :headers
     end

spec/factories/api_url_matches.rb

@@ -2,5 +2,7 @@
 
 FactoryGirl.define do
   factory :api_url_match, :class => 'Api::UrlMatch' do
+    frontend_prefix "/example-frontend/"
+    backend_prefix "/example-backend/"
   end
 end

spec/features/admin/apis_spec.rb

@@ -146,4 +146,28 @@
       find_field("Frontend Host").value.should eql("example2.com")
     end
   end
+
+  it "returns a validation error when all servers are removed from an existing API" do
+    api = FactoryGirl.create(:api)
+    visit "/admin/#/apis/#{api.id}/edit"
+    find("#servers_table a", :text => /Remove/).click
+    click_link("OK")
+    click_button("Save")
+    page.should have_content("must have at least one servers")
+
+    api = Api.find(api.id)
+    api.servers.length.should eql(1)
+  end
+
+  it "returns a validation error when all url prefixes are removed from an existing API" do
+    api = FactoryGirl.create(:api)
+    visit "/admin/#/apis/#{api.id}/edit"
+    find("#url_matches_table a", :text => /Remove/).click
+    click_link("OK")
+    click_button("Save")
+    page.should have_content("must have at least one url_matches")
+
+    api = Api.find(api.id)
+    api.url_matches.length.should eql(1)
+  end
 end