Normalizes request body and URL by parsing params to a list and sorti…

…ng (#211)

* Normalizes request body by parsing as params, then converting to a list

Before this change, if the request body was a list of params that were
in a different order than the params in the cassette, the request body
match would fail.

As of OTP 26, map key order is not guaranteed, so request bodies that
are created using maps can fail to match since the order of their keys
is not idempotent.

These changes convert the request body to a list of params and sort it
before comparing it to the request body in the cassette. This ensures
cassettes will be matched as long as their request bodies contain the
same set of key-value pairs as the incoming request body.

* Normalizes url by parsing params, converting to a list, and sorting

Before this change, if the url query params were in a different order
than the url params in the cassette, the request body match would fail.

As of OTP 26, map key order is not guaranteed, so url params that are
created using maps can fail to match since the order of their keys is
not idempotent.

These changes convert the url params to a list and sort it before
comparing it to the url in the cassette. This ensures cassettes will be
matched as long as their url params contain the same set of key-value
pairs as the incoming url params (and the rest of the url matches too).

fixture/custom_cassettes/response_mocking_with_param.json

@@ -1,7 +1,7 @@
 [
   {
     "request": {
-      "url": "http://example.com?auth_token=123abc",
+      "url": "http://example.com?auth_token=123abc&another_param=456",
       "method": "get"
     },
     "response": {

fixture/vcr_cassettes/different_query_params_on.json

@@ -5,7 +5,7 @@
       "headers": [],
       "method": "get",
       "options": [],
-      "url": "http://localhost:34006/server?p=3"
+      "url": "http://localhost:34006/server?p=3&q=string"
     },
     "response": {
       "body": "test_response_before",

lib/exvcr/handler.ex

@@ -112,13 +112,13 @@ defmodule ExVCR.Handler do
         pattern = Regex.compile!(Enum.at(match, 1))
         Regex.match?(pattern, key_url)
       else
-        request_url == key_url
+        normalize_url(request_url) == normalize_url(key_url)
       end
     else
       request_url = parse_url(request_url, recorder_options)
       key_url     = parse_url(key_url, recorder_options)
 
-      request_url == key_url
+      normalize_url(request_url) == normalize_url(key_url)
     end
   end
 
@@ -170,13 +170,35 @@ defmodule ExVCR.Handler do
         pattern = Regex.compile!(Enum.at(match, 1))
         Regex.match?(pattern, key_body)
       else
-        request_body == key_body
+        normalize_request_body(request_body) == normalize_request_body(key_body)
       end
     else
       true
     end
   end
 
+  defp normalize_url(url) do
+    original_url = URI.parse(url)
+
+    original_url
+    |> Map.put(:query, normalize_query(original_url.query))
+    |> URI.to_string()
+  end
+
+  defp normalize_request_body(request_body) do
+    normalize_query(request_body)
+  end
+
+  defp normalize_query(nil), do: nil 
+
+  defp normalize_query(query) do
+    query
+    |> URI.decode_query()
+    |> Map.to_list()
+    |> Enum.sort_by(fn {key, _val} -> key end)
+    |> URI.encode_query()
+  end
+
   defp get_response_from_server(request, recorder, record?) do
     adapter = ExVCR.Recorder.options(recorder)[:adapter]
     response = :meck.passthrough(request)

test/handler_custom_mode_test.exs

@@ -4,11 +4,10 @@ defmodule ExVCR.Adapter.HandlerCustomModeTest do
 
   test "query param match succeeds with custom mode" do
     use_cassette "response_mocking_with_param", custom: true do
-      HTTPotion.get("http://example.com?auth_token=123abc", []).body =~ ~r/Custom Response/
+      HTTPotion.get("http://example.com?another_param=456&auth_token=123abc", []).body =~ ~r/Custom Response/
     end
   end
 
-
   test "custom with valid response" do
     use_cassette "response_mocking", custom: true do
       assert HTTPotion.get("http://example.com", []).body =~ ~r/Custom Response/

test/handler_options_test.exs

@@ -17,7 +17,7 @@ defmodule ExVCR.Adapter.HandlerOptionsTest do
     test "specifying match_requests_on: [:query] matches query params" do
       use_cassette "different_query_params_on", match_requests_on: [:query] do
         HttpServer.start(path: "/server", port: @port, response: "test_response_before")
-        assert HTTPotion.get("#{@url}?p=3", []).body =~ ~r/test_response_before/
+        assert HTTPotion.get("#{@url}?q=string&p=3", []).body =~ ~r/test_response_before/
         HttpServer.stop(@port)
 
         # this method call should NOT be mocked as previous "test_response_before" response

test/handler_stub_mode_test.exs

@@ -31,6 +31,14 @@ defmodule ExVCR.Adapter.HandlerStubModeTest do
     end
   end
 
+  test "url matches as regardless of query param order" do
+    use_cassette :stub, [url: "http://localhost?param1=10&param2=20&param3=30"] do
+      {:ok, status_code, _headers, body} = :ibrowse.send_req('http://localhost?param3=30&param1=10&param2=20', [], :get)
+      assert status_code == '200'
+      assert to_string(body) =~ ~r/Hello World/
+    end
+  end
+
   test "url matches as regex" do
     use_cassette :stub, [url: "~r/.+/"] do
       {:ok, status_code, _headers, body} = :ibrowse.send_req('http://localhost', [], :get)
@@ -39,6 +47,14 @@ defmodule ExVCR.Adapter.HandlerStubModeTest do
     end
   end
 
+  test "request_body matches as string" do
+    use_cassette :stub, [url: 'http://localhost', method: :post, request_body: "some-string", body: "Hello World"] do
+      {:ok, status_code, _headers, body} = :ibrowse.send_req('http://localhost', [], :post, 'some-string')
+      assert status_code == '200'
+      assert to_string(body) =~ ~r/Hello World/
+    end
+  end
+
   test "request_body matches as regex" do
     use_cassette :stub, [url: 'http://localhost', method: :post, request_body: "~r/param1/", body: "Hello World"] do
       {:ok, status_code, _headers, body} = :ibrowse.send_req('http://localhost', [], :post, 'param1=value1&param2=value2')
@@ -55,6 +71,22 @@ defmodule ExVCR.Adapter.HandlerStubModeTest do
     end
   end
 
+  test "request_body matches as unordered list of params" do
+    use_cassette :stub, [url: 'http://localhost', method: :post, request_body: "param1=10&param3=30&param2=20", body: "Hello World"] do
+      {:ok, status_code, _headers, body} = :ibrowse.send_req('http://localhost', [], :post, 'param2=20&param1=10&param3=30')
+      assert status_code == '200'
+      assert to_string(body) =~ ~r/Hello World/
+    end
+  end
+
+  test "request_body mismatches as unordered list of params" do
+    assert_raise ExVCR.InvalidRequestError, fn ->
+      use_cassette :stub, [url: 'http://localhost', method: :post, request_body: "param1=10&param3=30&param4=40", body: "Hello World"] do
+        {:ok, _status_code, _headers, _body} = :ibrowse.send_req('http://localhost', [], :post, 'param2=20&param1=10&param3=30')
+      end
+    end
+  end
+
   test "request_body mismatch should raise error" do
     assert_raise ExVCR.InvalidRequestError, fn ->
       use_cassette :stub, [url: 'http://localhost', method: :post, request_body: '{"one" => 1}'] do