Fix: Plaid::ApiError (MAYBE-RAILS-78)

app/models/provider/plaid.rb

@@ -3,6 +3,7 @@
 
   MAYBE_SUPPORTED_PLAID_PRODUCTS = %w[transactions investments liabilities].freeze
   MAX_HISTORY_DAYS = Rails.env.development? ? 90 : 730
+  SUPPORTED_COUNTRY_CODES = %w[US CA GB FR ES IE NL DE IT PL DK NO SE EE LT LV PT BE].freeze
 
   class << self
     def process_webhook(webhook_body)
@@ -68,20 +69,26 @@
     @client = self.class.client
   end
 
-  def get_link_token(user_id:, webhooks_url:, redirect_url:, accountable_type: nil, eu: false)
+  def get_link_token(user_id:, webhooks_url:, redirect_url:, accountable_type: nil, country_code: "US")
+    country_code = country_code.to_s.upcase
+    country_code = "US" unless SUPPORTED_COUNTRY_CODES.include?(country_code)
+
     request = Plaid::LinkTokenCreateRequest.new({
-      user: { client_user_id: user_id },
+      user: { client_user_id: user_id.to_s },
       client_name: "Maybe Finance",
       products: [ get_primary_product(accountable_type) ],
       additional_consented_products: get_additional_consented_products(accountable_type),
-      country_codes: get_country_codes(eu),
+      country_codes: [country_code],
       language: "en",
       webhook: webhooks_url,
       redirect_uri: redirect_url,
       transactions: { days_requested: MAX_HISTORY_DAYS }
     })
 
     client.link_token_create(request)
+  rescue Plaid::ApiError => e
+    Rails.logger.error("Plaid link token creation failed: #{e.message}")
+    raise
   end
 
   def exchange_public_token(token)
@@ -198,12 +205,4 @@
     def get_additional_consented_products(accountable_type)
       MAYBE_SUPPORTED_PLAID_PRODUCTS - [ get_primary_product(accountable_type) ]
     end
-
-    def get_country_codes(eu)
-      if eu
-        [ "ES", "NL", "FR", "IE", "DE", "IT", "PL", "DK", "NO", "SE", "EE", "LT", "LV", "PT", "BE" ]  # EU supported countries
-      else
-        [ "US", "CA" ] # US + CA only
-      end
-    end
 end

test/models/provider/plaid_test.rb

@@ -0,0 +1,77 @@
+require "test_helper"
+
+class Provider::PlaidTest < ActiveSupport::TestCase
+  setup do
+    @provider = Provider::Plaid.new
+  end
+
+  test "get_link_token uses supported country code" do
+    mock_client = mock()
+    @provider.stubs(:client).returns(mock_client)
+
+    mock_client.expects(:link_token_create).with(
+      has_entries(
+        country_codes: ["CA"],
+        client_name: "Maybe Finance",
+        language: "en"
+      )
+    ).returns(OpenStruct.new(link_token: "test_token"))
+
+    response = @provider.get_link_token(
+      user_id: "123",
+      webhooks_url: "https://example.com/webhook",
+      redirect_url: "https://example.com/redirect",
+      country_code: "CA"
+    )
+
+    assert_equal "test_token", response.link_token
+  end
+
+  test "get_link_token defaults to US for unsupported country code" do
+    mock_client = mock()
+    @provider.stubs(:client).returns(mock_client)
+
+    mock_client.expects(:link_token_create).with(
+      has_entries(
+        country_codes: ["US"]
+      )
+    ).returns(OpenStruct.new(link_token: "test_token"))
+
+    response = @provider.get_link_token(
+      user_id: "123",
+      webhooks_url: "https://example.com/webhook",
+      redirect_url: "https://example.com/redirect",
+      country_code: "XX"
+    )
+
+    assert_equal "test_token", response.link_token
+  end
+
+  test "get_link_token handles nil country code" do
+    mock_client = mock()
+    @provider.stubs(:client).returns(mock_client)
+
+    mock_client.expects(:link_token_create).with(
+      has_entries(
+        country_codes: ["US"]
+      )
+    ).returns(OpenStruct.new(link_token: "test_token"))
+
+    response = @provider.get_link_token(
+      user_id: "123",
+      webhooks_url: "https://example.com/webhook",
+      redirect_url: "https://example.com/redirect",
+      country_code: nil
+    )
+
+    assert_equal "test_token", response.link_token
+  end
+
+  test "get_primary_product returns correct product for accountable type" do
+    assert_equal "investments", @provider.send(:get_primary_product, "Investment")
+    assert_equal "liabilities", @provider.send(:get_primary_product, "CreditCard")
+    assert_equal "liabilities", @provider.send(:get_primary_product, "Loan")
+    assert_equal "transactions", @provider.send(:get_primary_product, "Depository")
+    assert_equal "transactions", @provider.send(:get_primary_product, nil)
+  end
+end