Data provider simplification, tests, and documentation (#1997)

* Ignore env.test from source control

* Simplification of providers interface

* Synth tests

* Update money to use new find rates method

* Remove unused issues code

* Additional issue feature removals

* Update price data fetching and tests

* Update documentation for providers

* Security test fixes

* Fix self host test

* Update synth usage data access

* Remove AI pr schema changes

test/models/provider_test.rb

@@ -0,0 +1,61 @@
+require "test_helper"
+require "ostruct"
+
+class TestProvider < Provider
+  def fetch_data
+    provider_response(retries: 3) do
+      client.get("/test")
+    end
+  end
+
+  private
+    def client
+      @client ||= Faraday.new
+    end
+
+    def retryable_errors
+      [ Faraday::TimeoutError ]
+    end
+end
+
+class ProviderTest < ActiveSupport::TestCase
+  setup do
+    @provider = TestProvider.new
+  end
+
+  test "retries then provides failed response" do
+    client = mock
+    Faraday.stubs(:new).returns(client)
+
+    client.expects(:get)
+          .with("/test")
+          .raises(Faraday::TimeoutError)
+          .times(3)
+
+    response = @provider.fetch_data
+
+    assert_not response.success?
+    assert_match "timeout", response.error.message
+  end
+
+  test "fail, retry, succeed" do
+    client = mock
+    Faraday.stubs(:new).returns(client)
+
+    sequence = sequence("retry_sequence")
+
+    client.expects(:get)
+          .with("/test")
+          .raises(Faraday::TimeoutError)
+          .in_sequence(sequence)
+
+    client.expects(:get)
+          .with("/test")
+          .returns(Provider::ProviderResponse.new(success?: true, data: "success", error: nil))
+          .in_sequence(sequence)
+
+    response = @provider.fetch_data
+
+    assert response.success?
+  end
+end