Plaid sync domain improvements (#2267)

Breaks our Plaid sync process out into more manageable classes. Notably, this moves the sync process to a distinct, 2-step flow:

1. Import stage - we first make API calls and import Plaid data to "mirror" tables
2. Processing stage - read the raw data, apply business rules, build internal domain models and sync balances

This provides several benefits:

- Plaid syncs can now be "replayed" without fetching API data again
- Mirror tables provide better audit and debugging capabilities
- Eliminates the "all or nothing" sync behavior that is currently in place, which is brittle

test/models/plaid_account/importer_test.rb

@@ -0,0 +1,35 @@
+require "test_helper"
+
+class PlaidAccount::ImporterTest < ActiveSupport::TestCase
+  setup do
+    @mock_provider = PlaidMock.new
+    @plaid_account = plaid_accounts(:one)
+    @plaid_item = @plaid_account.plaid_item
+
+    @accounts_snapshot = PlaidItem::AccountsSnapshot.new(@plaid_item, plaid_provider: @mock_provider)
+    @account_snapshot = @accounts_snapshot.get_account_data(@plaid_account.plaid_id)
+  end
+
+  test "imports account data" do
+    PlaidAccount::Importer.new(@plaid_account, account_snapshot: @account_snapshot).import
+
+    assert_equal @account_snapshot.account_data.account_id, @plaid_account.plaid_id
+    assert_equal @account_snapshot.account_data.name, @plaid_account.name
+    assert_equal @account_snapshot.account_data.mask, @plaid_account.mask
+    assert_equal @account_snapshot.account_data.type, @plaid_account.plaid_type
+    assert_equal @account_snapshot.account_data.subtype, @plaid_account.plaid_subtype
+
+    # This account has transactions data
+    assert_equal PlaidMock::TRANSACTIONS.count, @plaid_account.raw_transactions_payload["added"].count
+
+    # This account does not have investment data
+    assert_equal 0, @plaid_account.raw_investments_payload["holdings"].count
+    assert_equal 0, @plaid_account.raw_investments_payload["securities"].count
+    assert_equal 0, @plaid_account.raw_investments_payload["transactions"].count
+
+    # This account is a credit card, so it should have liability data
+    assert_equal @plaid_account.plaid_id, @plaid_account.raw_liabilities_payload["credit"]["account_id"]
+    assert_nil @plaid_account.raw_liabilities_payload["mortgage"]
+    assert_nil @plaid_account.raw_liabilities_payload["student"]
+  end
+end

test/models/plaid_account/investments/balance_calculator_test.rb

@@ -0,0 +1,83 @@
+require "test_helper"
+
+class PlaidAccount::Investments::BalanceCalculatorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+
+    @plaid_account.update!(
+      plaid_type: "investment",
+      current_balance: 4000,
+      available_balance: 2000 # We ignore this since we have current_balance + holdings
+    )
+  end
+
+  test "calculates total balance from cash and positions" do
+    brokerage_cash_security_id = "plaid_brokerage_cash" # Plaid's brokerage cash security
+    cash_equivalent_security_id = "plaid_cash_equivalent" # Cash equivalent security (i.e. money market fund)
+    aapl_security_id = "plaid_aapl_security" # Regular stock security
+
+    test_investments = {
+      transactions: [], # Irrelevant for balance calcs, leave empty
+      holdings: [
+        # $1,000 in brokerage cash
+        {
+          security_id: brokerage_cash_security_id,
+          cost_basis: 1000,
+          institution_price: 1,
+          institution_value: 1000,
+          quantity: 1000
+        },
+        # $1,000 in money market funds
+        {
+          security_id: cash_equivalent_security_id,
+          cost_basis: 1000,
+          institution_price: 1,
+          institution_value: 1000,
+          quantity: 1000
+        },
+        # $2,000 worth of AAPL stock
+        {
+          security_id: aapl_security_id,
+          cost_basis: 2000,
+          institution_price: 200,
+          institution_value: 2000,
+          quantity: 10
+        }
+      ],
+      securities: [
+        {
+          security_id: brokerage_cash_security_id,
+          ticker_symbol: "CUR:USD",
+          is_cash_equivalent: true,
+          type: "cash"
+        },
+        {
+          security_id: cash_equivalent_security_id,
+          ticker_symbol: "VMFXX", # Vanguard Money Market Reserves
+          is_cash_equivalent: true,
+          type: "mutual fund"
+        },
+        {
+          security_id: aapl_security_id,
+          ticker_symbol: "AAPL",
+          is_cash_equivalent: false,
+          type: "equity",
+          market_identifier_code: "XNAS"
+        }
+      ]
+    }
+
+    @plaid_account.update!(raw_investments_payload: test_investments)
+
+    security_resolver = PlaidAccount::Investments::SecurityResolver.new(@plaid_account)
+    balance_calculator = PlaidAccount::Investments::BalanceCalculator.new(@plaid_account, security_resolver: security_resolver)
+
+    # We set this equal to `current_balance`
+    assert_equal 4000, balance_calculator.balance
+
+    # This is the sum of "non-brokerage-cash-holdings".  In the above test case, this means
+    # we're summing up $2,000 of AAPL + $1,000 Vanguard MM for $3,000 in holdings value.
+    # We back this $3,000 from the $4,000 total to get $1,000 in cash balance.
+    assert_equal 1000, balance_calculator.cash_balance
+  end
+end

test/models/plaid_account/investments/holdings_processor_test.rb

@@ -0,0 +1,49 @@
+require "test_helper"
+
+class PlaidAccount::Investments::HoldingsProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+    @security_resolver = PlaidAccount::Investments::SecurityResolver.new(@plaid_account)
+  end
+
+  test "creates holding records from Plaid holdings snapshot" do
+    test_investments_payload = {
+      securities: [], # mocked
+      holdings: [
+        {
+          "security_id" => "123",
+          "quantity" => 100,
+          "institution_price" => 100,
+          "iso_currency_code" => "USD"
+        }
+      ],
+      transactions: [] # not relevant for test
+    }
+
+    @plaid_account.update!(raw_investments_payload: test_investments_payload)
+
+    @security_resolver.expects(:resolve)
+                      .with(plaid_security_id: "123")
+                      .returns(
+                        OpenStruct.new(
+                          security: securities(:aapl),
+                          cash_equivalent?: false,
+                          brokerage_cash?: false
+                        )
+                      )
+
+    processor = PlaidAccount::Investments::HoldingsProcessor.new(@plaid_account, security_resolver: @security_resolver)
+
+    assert_difference "Holding.count" do
+      processor.process
+    end
+
+    holding = Holding.order(created_at: :desc).first
+
+    assert_equal 100, holding.qty
+    assert_equal 100, holding.price
+    assert_equal "USD", holding.currency
+    assert_equal securities(:aapl), holding.security
+    assert_equal Date.current, holding.date
+  end
+end

test/models/plaid_account/investments/security_resolver_test.rb

@@ -0,0 +1,115 @@
+require "test_helper"
+
+class PlaidAccount::Investments::SecurityResolverTest < ActiveSupport::TestCase
+  setup do
+    @upstream_resolver = mock("Security::Resolver")
+    @plaid_account = plaid_accounts(:one)
+    @resolver = PlaidAccount::Investments::SecurityResolver.new(@plaid_account)
+  end
+
+  test "handles missing plaid security" do
+    missing_id = "missing_security_id"
+
+    # Ensure there are *no* securities that reference the missing ID
+    @plaid_account.update!(raw_investments_payload: {
+      securities: [
+        {
+          "security_id" => "some_other_id",
+          "ticker_symbol" => "FOO",
+          "type" => "equity",
+          "market_identifier_code" => "XNAS"
+        }
+      ]
+    })
+
+    Security::Resolver.expects(:new).never
+    Sentry.stubs(:capture_exception)
+
+    response = @resolver.resolve(plaid_security_id: missing_id)
+
+    assert_nil response.security
+    refute response.cash_equivalent?
+    refute response.brokerage_cash?
+  end
+
+  test "identifies brokerage cash plaid securities" do
+    brokerage_cash_id = "brokerage_cash_security_id"
+
+    @plaid_account.update!(raw_investments_payload: {
+      securities: [
+        {
+          "security_id" => brokerage_cash_id,
+          "ticker_symbol" => "CUR:USD", # Plaid brokerage cash ticker
+          "type" => "cash",
+          "is_cash_equivalent" => true
+        }
+      ]
+    })
+
+    Security::Resolver.expects(:new).never
+
+    response = @resolver.resolve(plaid_security_id: brokerage_cash_id)
+
+    assert_nil response.security
+    assert response.cash_equivalent?
+    assert response.brokerage_cash?
+  end
+
+  test "identifies cash equivalent plaid securities" do
+    mmf_security_id = "money_market_security_id"
+
+    @plaid_account.update!(raw_investments_payload: {
+      securities: [
+        {
+          "security_id" => mmf_security_id,
+          "ticker_symbol" => "VMFXX", # Vanguard Federal Money Market Fund
+          "type" => "mutual fund",
+          "is_cash_equivalent" => true,
+          "market_identifier_code" => "XNAS"
+        }
+      ]
+    })
+
+    resolved_security = Security.create!(ticker: "VMFXX", exchange_operating_mic: "XNAS")
+
+    Security::Resolver.expects(:new)
+                     .with("VMFXX", exchange_operating_mic: "XNAS")
+                     .returns(@upstream_resolver)
+    @upstream_resolver.expects(:resolve).returns(resolved_security)
+
+    response = @resolver.resolve(plaid_security_id: mmf_security_id)
+
+    assert_equal resolved_security, response.security
+    assert response.cash_equivalent?
+    refute response.brokerage_cash?
+  end
+
+  test "resolves normal plaid securities" do
+    security_id = "regular_security_id"
+
+    @plaid_account.update!(raw_investments_payload: {
+      securities: [
+        {
+          "security_id" => security_id,
+          "ticker_symbol" => "IVV",
+          "type" => "etf",
+          "is_cash_equivalent" => false,
+          "market_identifier_code" => "XNAS"
+        }
+      ]
+    })
+
+    resolved_security = Security.create!(ticker: "IVV", exchange_operating_mic: "XNAS")
+
+    Security::Resolver.expects(:new)
+                     .with("IVV", exchange_operating_mic: "XNAS")
+                     .returns(@upstream_resolver)
+    @upstream_resolver.expects(:resolve).returns(resolved_security)
+
+    response = @resolver.resolve(plaid_security_id: security_id)
+
+    assert_equal resolved_security, response.security
+    refute response.cash_equivalent? # Normal securities are not cash equivalent
+    refute response.brokerage_cash?
+  end
+end

test/models/plaid_account/investments/transactions_processor_test.rb

@@ -0,0 +1,111 @@
+require "test_helper"
+
+class PlaidAccount::Investments::TransactionsProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+    @security_resolver = PlaidAccount::Investments::SecurityResolver.new(@plaid_account)
+  end
+
+
+  test "creates regular trade entries" do
+    test_investments_payload = {
+      transactions: [
+        {
+          "transaction_id" => "123",
+          "security_id" => "123",
+          "type" => "buy",
+          "quantity" => 1, # Positive, so "buy 1 share"
+          "price" => 100,
+          "iso_currency_code" => "USD",
+          "date" => Date.current,
+          "name" => "Buy 1 share of AAPL"
+        }
+      ]
+    }
+
+    @plaid_account.update!(raw_investments_payload: test_investments_payload)
+
+    @security_resolver.stubs(:resolve).returns(OpenStruct.new(
+      security: securities(:aapl)
+    ))
+
+    processor = PlaidAccount::Investments::TransactionsProcessor.new(@plaid_account, security_resolver: @security_resolver)
+
+    assert_difference [ "Entry.count", "Trade.count" ], 1 do
+      processor.process
+    end
+
+    entry = Entry.order(created_at: :desc).first
+
+    assert_equal 100, entry.amount
+    assert_equal "USD", entry.currency
+    assert_equal Date.current, entry.date
+    assert_equal "Buy 1 share of AAPL", entry.name
+  end
+
+  test "creates cash transactions" do
+    test_investments_payload = {
+      transactions: [
+        {
+          "transaction_id" => "123",
+          "type" => "cash",
+          "subtype" => "withdrawal",
+          "amount" => 100, # Positive, so moving money OUT of the account
+          "iso_currency_code" => "USD",
+          "date" => Date.current,
+          "name" => "Withdrawal"
+        }
+      ]
+    }
+
+    @plaid_account.update!(raw_investments_payload: test_investments_payload)
+
+    @security_resolver.expects(:resolve).never # Cash transactions don't have a security
+
+    processor = PlaidAccount::Investments::TransactionsProcessor.new(@plaid_account, security_resolver: @security_resolver)
+
+    assert_difference [ "Entry.count", "Transaction.count" ], 1 do
+      processor.process
+    end
+
+    entry = Entry.order(created_at: :desc).first
+
+    assert_equal 100, entry.amount
+    assert_equal "USD", entry.currency
+    assert_equal Date.current, entry.date
+    assert_equal "Withdrawal", entry.name
+  end
+
+  test "creates fee transactions" do
+    test_investments_payload = {
+      transactions: [
+        {
+          "transaction_id" => "123",
+          "type" => "fee",
+          "subtype" => "miscellaneous fee",
+          "amount" => 10.25,
+          "iso_currency_code" => "USD",
+          "date" => Date.current,
+          "name" => "Miscellaneous fee"
+        }
+      ]
+    }
+
+    @plaid_account.update!(raw_investments_payload: test_investments_payload)
+
+    @security_resolver.expects(:resolve).never # Cash transactions don't have a security
+
+    processor = PlaidAccount::Investments::TransactionsProcessor.new(@plaid_account, security_resolver: @security_resolver)
+
+    assert_difference [ "Entry.count", "Transaction.count" ], 1 do
+      processor.process
+    end
+
+    entry = Entry.order(created_at: :desc).first
+
+    assert_equal 10.25, entry.amount
+    assert_equal "USD", entry.currency
+    assert_equal Date.current, entry.date
+    assert_equal "Miscellaneous fee", entry.name
+  end
+end

test/models/plaid_account/liabilities/credit_processor_test.rb

@@ -0,0 +1,39 @@
+require "test_helper"
+
+class PlaidAccount::Liabilities::CreditProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+    @plaid_account.update!(
+      plaid_type: "credit",
+      plaid_subtype: "credit_card"
+    )
+
+    @plaid_account.account.update!(
+      accountable: CreditCard.new,
+    )
+  end
+
+  test "updates credit card minimum payment and APR from Plaid data" do
+    @plaid_account.update!(raw_liabilities_payload: {
+      credit: {
+        minimum_payment_amount: 100,
+        aprs: [ { apr_percentage: 15.0 } ]
+      }
+    })
+
+    processor = PlaidAccount::Liabilities::CreditProcessor.new(@plaid_account)
+    processor.process
+
+    assert_equal 100, @plaid_account.account.credit_card.minimum_payment
+    assert_equal 15.0, @plaid_account.account.credit_card.apr
+  end
+
+  test "does nothing when liability data absent" do
+    @plaid_account.update!(raw_liabilities_payload: {})
+    processor = PlaidAccount::Liabilities::CreditProcessor.new(@plaid_account)
+    processor.process
+
+    assert_nil @plaid_account.account.credit_card.minimum_payment
+    assert_nil @plaid_account.account.credit_card.apr
+  end
+end

test/models/plaid_account/liabilities/mortgage_processor_test.rb

@@ -0,0 +1,44 @@
+require "test_helper"
+
+class PlaidAccount::Liabilities::MortgageProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+    @plaid_account.update!(
+      plaid_type: "loan",
+      plaid_subtype: "mortgage"
+    )
+
+    @plaid_account.account.update!(accountable: Loan.new)
+  end
+
+  test "updates loan interest rate and type from Plaid data" do
+    @plaid_account.update!(raw_liabilities_payload: {
+      mortgage: {
+        interest_rate: {
+          type: "fixed",
+          percentage: 4.25
+        }
+      }
+    })
+
+    processor = PlaidAccount::Liabilities::MortgageProcessor.new(@plaid_account)
+    processor.process
+
+    loan = @plaid_account.account.loan
+
+    assert_equal "fixed", loan.rate_type
+    assert_equal 4.25, loan.interest_rate
+  end
+
+  test "does nothing when mortgage data absent" do
+    @plaid_account.update!(raw_liabilities_payload: {})
+
+    processor = PlaidAccount::Liabilities::MortgageProcessor.new(@plaid_account)
+    processor.process
+
+    loan = @plaid_account.account.loan
+
+    assert_nil loan.rate_type
+    assert_nil loan.interest_rate
+  end
+end

test/models/plaid_account/liabilities/student_loan_processor_test.rb

@@ -0,0 +1,68 @@
+require "test_helper"
+
+class PlaidAccount::Liabilities::StudentLoanProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+    @plaid_account.update!(
+      plaid_type: "loan",
+      plaid_subtype: "student"
+    )
+
+    # Change the underlying accountable to a Loan so the helper method `loan` is available
+    @plaid_account.account.update!(accountable: Loan.new)
+  end
+
+  test "updates loan details including term months from Plaid data" do
+    @plaid_account.update!(raw_liabilities_payload: {
+      student: {
+        interest_rate_percentage: 5.5,
+        origination_principal_amount: 20000,
+        origination_date: Date.new(2020, 1, 1),
+        expected_payoff_date: Date.new(2022, 1, 1)
+      }
+    })
+
+    processor = PlaidAccount::Liabilities::StudentLoanProcessor.new(@plaid_account)
+    processor.process
+
+    loan = @plaid_account.account.loan
+
+    assert_equal "fixed", loan.rate_type
+    assert_equal 5.5, loan.interest_rate
+    assert_equal 20000, loan.initial_balance
+    assert_equal 24, loan.term_months
+  end
+
+  test "handles missing payoff dates gracefully" do
+    @plaid_account.update!(raw_liabilities_payload: {
+      student: {
+        interest_rate_percentage: 4.8,
+        origination_principal_amount: 15000,
+        origination_date: Date.new(2021, 6, 1)
+        # expected_payoff_date omitted
+      }
+    })
+
+    processor = PlaidAccount::Liabilities::StudentLoanProcessor.new(@plaid_account)
+    processor.process
+
+    loan = @plaid_account.account.loan
+
+    assert_nil loan.term_months
+    assert_equal 4.8, loan.interest_rate
+    assert_equal 15000, loan.initial_balance
+  end
+
+  test "does nothing when loan data absent" do
+    @plaid_account.update!(raw_liabilities_payload: {})
+
+    processor = PlaidAccount::Liabilities::StudentLoanProcessor.new(@plaid_account)
+    processor.process
+
+    loan = @plaid_account.account.loan
+
+    assert_nil loan.interest_rate
+    assert_nil loan.initial_balance
+    assert_nil loan.term_months
+  end
+end

test/models/plaid_account/processor_test.rb

@@ -0,0 +1,172 @@
+require "test_helper"
+
+class PlaidAccount::ProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+  end
+
+  test "processes new account and assigns attributes" do
+    Account.destroy_all # Clear out internal accounts so we start fresh
+
+    expect_default_subprocessor_calls
+
+    @plaid_account.update!(
+      plaid_id: "test_plaid_id",
+      plaid_type: "depository",
+      plaid_subtype: "checking",
+      current_balance: 1000,
+      available_balance: 1000,
+      currency: "USD",
+      name: "Test Plaid Account",
+      mask: "1234"
+    )
+
+    assert_difference "Account.count" do
+      PlaidAccount::Processor.new(@plaid_account).process
+    end
+
+    @plaid_account.reload
+
+    account = Account.order(created_at: :desc).first
+    assert_equal "Test Plaid Account", account.name
+    assert_equal @plaid_account.id, account.plaid_account_id
+    assert_equal "checking", account.subtype
+    assert_equal 1000, account.balance
+    assert_equal 1000, account.cash_balance
+    assert_equal "USD", account.currency
+    assert_equal "Depository", account.accountable_type
+    assert_equal "checking", account.subtype
+  end
+
+  test "processing is idempotent with updates and enrichments" do
+    expect_default_subprocessor_calls
+
+    assert_equal "Plaid Depository Account", @plaid_account.account.name
+    assert_equal "checking", @plaid_account.account.subtype
+
+    @plaid_account.account.update!(
+      name: "User updated name",
+      subtype: "savings",
+      balance: 2000 # User cannot override balance.  This will be overridden by the processor on next processing
+    )
+
+    @plaid_account.account.lock_attr!(:name)
+    @plaid_account.account.lock_attr!(:subtype)
+    @plaid_account.account.lock_attr!(:balance) # Even if balance somehow becomes locked, Plaid ignores it and overrides it
+
+    assert_no_difference "Account.count" do
+      PlaidAccount::Processor.new(@plaid_account).process
+    end
+
+    @plaid_account.reload
+
+    assert_equal "User updated name", @plaid_account.account.name
+    assert_equal "savings", @plaid_account.account.subtype
+    assert_equal @plaid_account.current_balance, @plaid_account.account.balance # Overriden by processor
+  end
+
+  test "account processing failure halts further processing" do
+    Account.any_instance.stubs(:save!).raises(StandardError.new("Test error"))
+
+    PlaidAccount::Transactions::Processor.any_instance.expects(:process).never
+    PlaidAccount::Investments::TransactionsProcessor.any_instance.expects(:process).never
+    PlaidAccount::Investments::HoldingsProcessor.any_instance.expects(:process).never
+
+    expect_no_investment_balance_calculator_calls
+    expect_no_liability_processor_calls
+
+    assert_raises(StandardError) do
+      PlaidAccount::Processor.new(@plaid_account).process
+    end
+  end
+
+  test "product processing failure reports exception and continues processing" do
+    PlaidAccount::Transactions::Processor.any_instance.stubs(:process).raises(StandardError.new("Test error"))
+
+    # Subsequent product processors still run
+    expect_investment_product_processor_calls
+
+    assert_nothing_raised do
+      PlaidAccount::Processor.new(@plaid_account).process
+    end
+  end
+
+  test "calculates balance using BalanceCalculator for investment accounts" do
+    @plaid_account.update!(plaid_type: "investment")
+
+    PlaidAccount::Investments::BalanceCalculator.any_instance.expects(:balance).returns(1000).once
+    PlaidAccount::Investments::BalanceCalculator.any_instance.expects(:cash_balance).returns(1000).once
+
+    PlaidAccount::Processor.new(@plaid_account).process
+  end
+
+  test "processes credit liability data" do
+    expect_investment_product_processor_calls
+    expect_no_investment_balance_calculator_calls
+    expect_depository_product_processor_calls
+
+    @plaid_account.update!(plaid_type: "credit", plaid_subtype: "credit card")
+
+    PlaidAccount::Liabilities::CreditProcessor.any_instance.expects(:process).once
+    PlaidAccount::Liabilities::MortgageProcessor.any_instance.expects(:process).never
+    PlaidAccount::Liabilities::StudentLoanProcessor.any_instance.expects(:process).never
+
+    PlaidAccount::Processor.new(@plaid_account).process
+  end
+
+  test "processes mortgage liability data" do
+    expect_investment_product_processor_calls
+    expect_no_investment_balance_calculator_calls
+    expect_depository_product_processor_calls
+
+    @plaid_account.update!(plaid_type: "loan", plaid_subtype: "mortgage")
+
+    PlaidAccount::Liabilities::CreditProcessor.any_instance.expects(:process).never
+    PlaidAccount::Liabilities::MortgageProcessor.any_instance.expects(:process).once
+    PlaidAccount::Liabilities::StudentLoanProcessor.any_instance.expects(:process).never
+
+    PlaidAccount::Processor.new(@plaid_account).process
+  end
+
+  test "processes student loan liability data" do
+    expect_investment_product_processor_calls
+    expect_no_investment_balance_calculator_calls
+    expect_depository_product_processor_calls
+
+    @plaid_account.update!(plaid_type: "loan", plaid_subtype: "student")
+
+    PlaidAccount::Liabilities::CreditProcessor.any_instance.expects(:process).never
+    PlaidAccount::Liabilities::MortgageProcessor.any_instance.expects(:process).never
+    PlaidAccount::Liabilities::StudentLoanProcessor.any_instance.expects(:process).once
+
+    PlaidAccount::Processor.new(@plaid_account).process
+  end
+
+  private
+    def expect_investment_product_processor_calls
+      PlaidAccount::Investments::TransactionsProcessor.any_instance.expects(:process).once
+      PlaidAccount::Investments::HoldingsProcessor.any_instance.expects(:process).once
+    end
+
+    def expect_depository_product_processor_calls
+      PlaidAccount::Transactions::Processor.any_instance.expects(:process).once
+    end
+
+    def expect_no_investment_balance_calculator_calls
+      PlaidAccount::Investments::BalanceCalculator.any_instance.expects(:balance).never
+      PlaidAccount::Investments::BalanceCalculator.any_instance.expects(:cash_balance).never
+    end
+
+    def expect_no_liability_processor_calls
+      PlaidAccount::Liabilities::CreditProcessor.any_instance.expects(:process).never
+      PlaidAccount::Liabilities::MortgageProcessor.any_instance.expects(:process).never
+      PlaidAccount::Liabilities::StudentLoanProcessor.any_instance.expects(:process).never
+    end
+
+    def expect_default_subprocessor_calls
+      expect_depository_product_processor_calls
+      expect_investment_product_processor_calls
+      expect_no_investment_balance_calculator_calls
+      expect_no_liability_processor_calls
+    end
+end

test/models/plaid_account/transactions/category_matcher_test.rb

@@ -1,6 +1,6 @@
 require "test_helper"
 
-class Provider::Plaid::CategoryAliasMatcherTest < ActiveSupport::TestCase
+class PlaidAccount::Transactions::CategoryMatcherTest < ActiveSupport::TestCase
   setup do
     @family = families(:empty)
 
@@ -32,7 +32,7 @@ class Provider::Plaid::CategoryAliasMatcherTest < ActiveSupport::TestCase
 
     @giving = @family.categories.create!(name: "Giving")
 
-    @matcher = Provider::Plaid::CategoryAliasMatcher.new(@family.categories)
+    @matcher = PlaidAccount::Transactions::CategoryMatcher.new(@family.categories)
   end
 
   test "matches expense categories" do

test/models/plaid_account/transactions/processor_test.rb

@@ -0,0 +1,63 @@
+require "test_helper"
+
+class PlaidAccount::Transactions::ProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+  end
+
+  test "processes added and modified plaid transactions" do
+    added_transactions = [ { "transaction_id" => "123" } ]
+    modified_transactions = [ { "transaction_id" => "456" } ]
+
+    @plaid_account.update!(raw_transactions_payload: {
+      added: added_transactions,
+      modified: modified_transactions,
+      removed: []
+    })
+
+    mock_processor = mock("PlaidEntry::Processor")
+    category_matcher_mock = mock("PlaidAccount::Transactions::CategoryMatcher")
+
+    PlaidAccount::Transactions::CategoryMatcher.stubs(:new).returns(category_matcher_mock)
+    PlaidEntry::Processor.expects(:new)
+                         .with(added_transactions.first, plaid_account: @plaid_account, category_matcher: category_matcher_mock)
+                         .returns(mock_processor)
+                         .once
+
+    PlaidEntry::Processor.expects(:new)
+                         .with(modified_transactions.first, plaid_account: @plaid_account, category_matcher: category_matcher_mock)
+                         .returns(mock_processor)
+                         .once
+
+    mock_processor.expects(:process).twice
+
+    processor = PlaidAccount::Transactions::Processor.new(@plaid_account)
+    processor.process
+  end
+
+  test "removes transactions no longer in plaid" do
+    destroyable_transaction_id = "destroy_me"
+    @plaid_account.account.entries.create!(
+      plaid_id: destroyable_transaction_id,
+      date: Date.current,
+      amount: 100,
+      name: "Destroy me",
+      currency: "USD",
+      entryable: Transaction.new
+    )
+
+    @plaid_account.update!(raw_transactions_payload: {
+      added: [],
+      modified: [],
+      removed: [ { "transaction_id" => destroyable_transaction_id } ]
+    })
+
+    processor = PlaidAccount::Transactions::Processor.new(@plaid_account)
+
+    assert_difference [ "Entry.count", "Transaction.count" ], -1 do
+      processor.process
+    end
+
+    assert_nil Entry.find_by(plaid_id: destroyable_transaction_id)
+  end
+end

test/models/plaid_account/type_mappable_test.rb

@@ -0,0 +1,35 @@
+require "test_helper"
+
+class PlaidAccount::TypeMappableTest < ActiveSupport::TestCase
+  setup do
+    class MockProcessor
+      include PlaidAccount::TypeMappable
+    end
+
+    @mock_processor = MockProcessor.new
+  end
+
+  test "maps types to accountables" do
+    assert_instance_of Depository, @mock_processor.map_accountable("depository")
+    assert_instance_of Investment, @mock_processor.map_accountable("investment")
+    assert_instance_of CreditCard, @mock_processor.map_accountable("credit")
+    assert_instance_of Loan, @mock_processor.map_accountable("loan")
+    assert_instance_of OtherAsset, @mock_processor.map_accountable("other")
+  end
+
+  test "maps subtypes" do
+    assert_equal "checking", @mock_processor.map_subtype("depository", "checking")
+    assert_equal "roth_ira", @mock_processor.map_subtype("investment", "roth")
+  end
+
+  test "raises on invalid types" do
+    assert_raises PlaidAccount::TypeMappable::UnknownAccountTypeError do
+      @mock_processor.map_accountable("unknown")
+    end
+  end
+
+  test "handles nil subtypes" do
+    assert_equal "other", @mock_processor.map_subtype("depository", nil)
+    assert_equal "other", @mock_processor.map_subtype("depository", "unknown")
+  end
+end

test/models/plaid_entry/processor_test.rb

@@ -0,0 +1,91 @@
+require "test_helper"
+
+class PlaidEntry::ProcessorTest < ActiveSupport::TestCase
+  setup do
+    @plaid_account = plaid_accounts(:one)
+    @category_matcher = mock("PlaidAccount::Transactions::CategoryMatcher")
+  end
+
+  test "creates new entry transaction" do
+    plaid_transaction = {
+      "transaction_id" => "123",
+      "merchant_name" => "Amazon", # this is used for merchant and entry name
+      "amount" => 100,
+      "date" => Date.current,
+      "iso_currency_code" => "USD",
+      "personal_finance_category" => {
+        "detailed" => "Food"
+      },
+      "merchant_entity_id" => "123"
+    }
+
+    @category_matcher.expects(:match).with("Food").returns(categories(:food_and_drink))
+
+    processor = PlaidEntry::Processor.new(
+      plaid_transaction,
+      plaid_account: @plaid_account,
+      category_matcher: @category_matcher
+    )
+
+    assert_difference [ "Entry.count", "Transaction.count", "ProviderMerchant.count" ], 1 do
+      processor.process
+    end
+
+    entry = Entry.order(created_at: :desc).first
+
+    assert_equal 100, entry.amount
+    assert_equal "USD", entry.currency
+    assert_equal Date.current, entry.date
+    assert_equal "Amazon", entry.name
+    assert_equal categories(:food_and_drink).id, entry.transaction.category_id
+
+    provider_merchant = ProviderMerchant.order(created_at: :desc).first
+
+    assert_equal "Amazon", provider_merchant.name
+  end
+
+  test "updates existing entry transaction" do
+    existing_plaid_id = "existing_plaid_id"
+
+    plaid_transaction = {
+      "transaction_id" => existing_plaid_id,
+      "merchant_name" => "Amazon", # this is used for merchant and entry name
+      "amount" => 200, # Changed amount will be updated
+      "date" => 1.day.ago.to_date, # Changed date will be updated
+      "iso_currency_code" => "USD",
+      "personal_finance_category" => {
+        "detailed" => "Food"
+      }
+    }
+
+    @category_matcher.expects(:match).with("Food").returns(categories(:food_and_drink))
+
+    # Create an existing entry
+    @plaid_account.account.entries.create!(
+      plaid_id: existing_plaid_id,
+      amount: 100,
+      currency: "USD",
+      date: Date.current,
+      name: "Amazon",
+      entryable: Transaction.new
+    )
+
+    processor = PlaidEntry::Processor.new(
+      plaid_transaction,
+      plaid_account: @plaid_account,
+      category_matcher: @category_matcher
+    )
+
+    assert_no_difference [ "Entry.count", "Transaction.count", "ProviderMerchant.count" ] do
+      processor.process
+    end
+
+    entry = Entry.order(created_at: :desc).first
+
+    assert_equal 200, entry.amount
+    assert_equal "USD", entry.currency
+    assert_equal 1.day.ago.to_date, entry.date
+    assert_equal "Amazon", entry.name
+    assert_equal categories(:food_and_drink).id, entry.transaction.category_id
+  end
+end

test/models/plaid_investment_sync_test.rb

@@ -1,82 +0,0 @@
-require "test_helper"
-
-class PlaidInvestmentSyncTest < ActiveSupport::TestCase
-  include PlaidTestHelper
-
-  setup do
-    @plaid_account = plaid_accounts(:one)
-  end
-
-  test "syncs basic investments and handles cash holding" do
-    assert_equal 0, @plaid_account.account.entries.count
-    assert_equal 0, @plaid_account.account.holdings.count
-
-    plaid_aapl_id = "aapl_id"
-
-    transactions = [
-      create_plaid_investment_transaction({
-        investment_transaction_id: "inv_txn_1",
-        security_id: plaid_aapl_id,
-        quantity: 10,
-        price: 200,
-        date: 5.days.ago.to_date,
-        type: "buy"
-      })
-    ]
-
-    holdings = [
-      create_plaid_cash_holding,
-      create_plaid_holding({
-        security_id: plaid_aapl_id,
-        quantity: 10,
-        institution_price: 200,
-        cost_basis: 2000
-      })
-    ]
-
-    securities = [
-      create_plaid_security({
-        security_id: plaid_aapl_id,
-        close_price: 200,
-        ticker_symbol: "AAPL"
-      })
-    ]
-
-    # Cash holding should be ignored, resulting in 1, NOT 2 total holdings after sync
-    assert_difference -> { Trade.count } => 1,
-                      -> { Transaction.count } => 0,
-                      -> { Holding.count } => 1,
-                      -> { Security.count } => 0 do
-      PlaidInvestmentSync.new(@plaid_account).sync!(
-        transactions: transactions,
-        holdings: holdings,
-        securities: securities
-      )
-    end
-  end
-
-  # Some cash transactions from Plaid are labeled as type: "cash" while others are linked to a "cash" security
-  # In both cases, we should treat them as cash-only transactions (not trades)
-  test "handles cash investment transactions" do
-    transactions = [
-      create_plaid_investment_transaction({
-        price: 1,
-        quantity: 5,
-        amount: 5,
-        type: "fee",
-        subtype: "miscellaneous fee",
-        security_id: PLAID_TEST_CASH_SECURITY_ID
-      })
-    ]
-
-    assert_difference -> { Trade.count } => 0,
-                      -> { Transaction.count } => 1,
-                      -> { Security.count } => 0 do
-      PlaidInvestmentSync.new(@plaid_account).sync!(
-        transactions: transactions,
-        holdings: [ create_plaid_cash_holding ],
-        securities: [ create_plaid_cash_security ]
-      )
-    end
-  end
-end

test/models/plaid_item/importer_test.rb

@@ -0,0 +1,23 @@
+require "test_helper"
+require "ostruct"
+
+class PlaidItem::ImporterTest < ActiveSupport::TestCase
+  setup do
+    @mock_provider = PlaidMock.new
+    @plaid_item = plaid_items(:one)
+    @importer = PlaidItem::Importer.new(@plaid_item, plaid_provider: @mock_provider)
+  end
+
+  test "imports item metadata" do
+    PlaidAccount::Importer.any_instance.expects(:import).times(PlaidMock::ACCOUNTS.count)
+
+    PlaidItem::Importer.new(@plaid_item, plaid_provider: @mock_provider).import
+
+    assert_equal PlaidMock::ITEM.institution_id, @plaid_item.institution_id
+    assert_equal PlaidMock::ITEM.available_products, @plaid_item.available_products
+    assert_equal PlaidMock::ITEM.billed_products, @plaid_item.billed_products
+
+    assert_equal PlaidMock::ITEM.item_id, @plaid_item.raw_payload["item_id"]
+    assert_equal PlaidMock::INSTITUTION.institution_id, @plaid_item.raw_institution_payload["institution_id"]
+  end
+end

test/models/plaid_item_test.rb

@@ -5,11 +5,11 @@ class PlaidItemTest < ActiveSupport::TestCase
 
   setup do
     @plaid_item = @syncable = plaid_items(:one)
+    @plaid_provider = mock
+    Provider::Registry.stubs(:plaid_provider_for_region).returns(@plaid_provider)
   end
 
   test "removes plaid item when destroyed" do
-    @plaid_provider = mock
-    @plaid_item.stubs(:plaid_provider).returns(@plaid_provider)
     @plaid_provider.expects(:remove_item).with(@plaid_item.access_token).once
 
     assert_difference "PlaidItem.count", -1 do
@@ -18,8 +18,6 @@ class PlaidItemTest < ActiveSupport::TestCase
   end
 
   test "if plaid item not found, silently continues with deletion" do
-    @plaid_provider = mock
-    @plaid_item.stubs(:plaid_provider).returns(@plaid_provider)
     @plaid_provider.expects(:remove_item).with(@plaid_item.access_token).raises(Plaid::ApiError.new("Item not found"))
 
     assert_difference "PlaidItem.count", -1 do

test/models/provider/plaid_test.rb

@@ -0,0 +1,80 @@
+require "test_helper"
+
+class Provider::PlaidTest < ActiveSupport::TestCase
+  setup do
+    # Do not change, this is whitelisted in the Plaid Dashboard for local dev
+    @redirect_url = "http://localhost:3000/accounts"
+
+    # A specialization of Plaid client with sandbox-only extensions
+    @plaid = Provider::PlaidSandbox.new
+  end
+
+  test "gets link token" do
+    VCR.use_cassette("plaid/link_token") do
+      link_token = @plaid.get_link_token(
+        user_id: "test-user-id",
+        webhooks_url: "https://example.com/webhooks",
+        redirect_url: @redirect_url
+      )
+
+      assert_match /link-sandbox-.*/, link_token.link_token
+    end
+  end
+
+  test "exchanges public token" do
+    VCR.use_cassette("plaid/exchange_public_token") do
+      public_token = @plaid.create_public_token
+      exchange_response = @plaid.exchange_public_token(public_token)
+
+      assert_match /access-sandbox-.*/, exchange_response.access_token
+    end
+  end
+
+  test "gets item" do
+    VCR.use_cassette("plaid/get_item") do
+      access_token = get_access_token
+      item = @plaid.get_item(access_token).item
+
+      assert_equal "ins_109508", item.institution_id
+      assert_equal "First Platypus Bank", item.institution_name
+    end
+  end
+
+  test "gets item accounts" do
+    VCR.use_cassette("plaid/get_item_accounts") do
+      access_token = get_access_token
+      accounts_response = @plaid.get_item_accounts(access_token)
+
+      assert_equal 4, accounts_response.accounts.size
+    end
+  end
+
+  test "gets item investments" do
+    VCR.use_cassette("plaid/get_item_investments") do
+      access_token = get_access_token
+      investments_response = @plaid.get_item_investments(access_token)
+
+      assert_equal 3, investments_response.holdings.size
+      assert_equal 4, investments_response.transactions.size
+    end
+  end
+
+  test "gets item liabilities" do
+    VCR.use_cassette("plaid/get_item_liabilities") do
+      access_token = get_access_token
+      liabilities_response = @plaid.get_item_liabilities(access_token)
+
+      assert liabilities_response.credit.count > 0
+      assert liabilities_response.student.count > 0
+    end
+  end
+
+  private
+    def get_access_token
+      VCR.use_cassette("plaid/access_token") do
+        public_token = @plaid.create_public_token
+        exchange_response = @plaid.exchange_public_token(public_token)
+        exchange_response.access_token
+      end
+    end
+end