Clarify backend data pipeline naming concepts (importers, processors, materializers, calculators, and syncers) (#2255)

* Rename MarketDataSyncer to MarketDataImporter

* Materializers

* Importers

* More reference replacements

test/models/market_data_importer_test.rb

@@ -0,0 +1,85 @@
+require "test_helper"
+require "ostruct"
+
+class MarketDataImporterTest < ActiveSupport::TestCase
+  include ProviderTestHelper
+
+  SNAPSHOT_START_DATE = MarketDataImporter::SNAPSHOT_DAYS.days.ago.to_date
+  PROVIDER_BUFFER     = 5.days
+
+  setup do
+    Security::Price.delete_all
+    ExchangeRate.delete_all
+    Trade.delete_all
+    Holding.delete_all
+    Security.delete_all
+
+    @provider = mock("provider")
+    Provider::Registry.any_instance
+                      .stubs(:get_provider)
+                      .with(:synth)
+                      .returns(@provider)
+  end
+
+  test "syncs required exchange rates" do
+    family = Family.create!(name: "Smith", currency: "USD")
+    family.accounts.create!(name: "Chequing",
+                            currency: "CAD",
+                            balance: 100,
+                            accountable: Depository.new)
+
+    # Seed stale rate so only the next missing day is fetched
+    ExchangeRate.create!(from_currency: "CAD",
+                         to_currency: "USD",
+                         date: SNAPSHOT_START_DATE,
+                         rate: 2.0)
+
+    expected_start_date = (SNAPSHOT_START_DATE + 1.day) - PROVIDER_BUFFER
+    end_date            = Date.current.in_time_zone("America/New_York").to_date
+
+    @provider.expects(:fetch_exchange_rates)
+             .with(from: "CAD",
+                   to: "USD",
+                   start_date: expected_start_date,
+                   end_date: end_date)
+             .returns(provider_success_response([
+               OpenStruct.new(from: "CAD", to: "USD", date: SNAPSHOT_START_DATE, rate: 1.5)
+             ]))
+
+    before = ExchangeRate.count
+    MarketDataImporter.new(mode: :snapshot).import_exchange_rates
+    after  = ExchangeRate.count
+
+    assert_operator after, :>, before, "Should insert at least one new exchange-rate row"
+  end
+
+  test "syncs security prices" do
+    security = Security.create!(ticker: "AAPL", exchange_operating_mic: "XNAS")
+
+    expected_start_date = SNAPSHOT_START_DATE - PROVIDER_BUFFER
+    end_date            = Date.current.in_time_zone("America/New_York").to_date
+
+    @provider.expects(:fetch_security_prices)
+             .with(symbol: security.ticker,
+                   exchange_operating_mic: security.exchange_operating_mic,
+                   start_date: expected_start_date,
+                   end_date: end_date)
+             .returns(provider_success_response([
+               OpenStruct.new(security: security,
+                              date: SNAPSHOT_START_DATE,
+                              price: 100,
+                              currency: "USD")
+             ]))
+
+    @provider.stubs(:fetch_security_info)
+             .with(symbol: "AAPL", exchange_operating_mic: "XNAS")
+             .returns(provider_success_response(OpenStruct.new(name: "Apple", logo_url: "logo")))
+
+    # Ignore exchange rate calls for this test
+    @provider.stubs(:fetch_exchange_rates).returns(provider_success_response([]))
+
+    MarketDataImporter.new(mode: :snapshot).import_security_prices
+
+    assert_equal 1, Security::Price.where(security: security, date: SNAPSHOT_START_DATE).count
+  end
+end