[resty.http_ng] globally stub http_ng default backend

in unit tests, it should default to test backend

gateway/src/resty/http_ng.lua

@@ -243,9 +243,13 @@ local function generate_client_method(client, method_or_format)
   return add_http_method(client, method_or_format) or chain_serializer(client, method_or_format)
 end
 
+function http.backend()
+  return resty_backend
+end
+
 function http.new(client)
   client = client or { }
-  client.backend = client.backend or resty_backend
+  client.backend = client.backend or http.backend()
 
   return setmetatable(client, { __index  = generate_client_method  })
 end

spec/resty/http_ng_spec.lua

@@ -1,12 +1,12 @@
 local http_ng = require 'resty.http_ng'
 local fake_backend = require 'fake_backend_helper'
-
+local resty_backend = require 'resty.http_ng.backend.resty'
 
 describe('http_ng', function()
   local http, backend
   before_each(function()
     backend = fake_backend.new()
-    http = http_ng.new({backend = backend})
+    http = http_ng.new{ backend = backend }
   end)
 
   for _,method in ipairs{ 'get', 'head', 'options', 'delete' } do
@@ -210,7 +210,7 @@ describe('http_ng', function()
   describe('when there is no error', function()
     local response
     before_each(function()
-      http = http_ng.new{}
+      http = http_ng.new{ backend = resty_backend }
       response = http.get('http://127.0.0.1:1984')
     end)
 
@@ -226,7 +226,7 @@ describe('http_ng', function()
   describe('when there is error #network', function()
     local response
     before_each(function()
-      http = http_ng.new{}
+      http = http_ng.new{ backend = resty_backend }
       response = http.get('http://127.0.0.1:1')
     end)
 
@@ -242,7 +242,7 @@ describe('http_ng', function()
   describe('works with api.twitter.com #network', function()
 
     it('connects #twitter', function()
-      local client = http_ng.new{}
+      local client = http_ng.new{ backend = resty_backend }
       local response = client.get('http://api.twitter.com/')
       assert(response.ok, 'response is not ok')
     end)

spec/spec_helper.lua

@@ -131,3 +131,21 @@ _G.fixture = function (...)
 
    return file.read(path.join('spec', 'fixtures', ...))
 end
+
+do -- stub http_ng
+  local http_ng = require('resty.http_ng')
+  local test_backend_client = require 'resty.http_ng.backend.test'
+  local test_backend
+  local stub = require('luassert.stub')
+  local stubbed
+
+  busted.before_each(function(...)
+    test_backend = test_backend_client.new()
+    stubbed = stub(http_ng, 'backend', test_backend)
+  end)
+
+  busted.after_each(function()
+    test_backend.verify_no_outstanding_expectations()
+    stubbed:revert()
+  end)
+end