Send customer_id to TaxJar API

This is required to support per-customer exemptions through the TaxJar
API.

3 files changed, 16 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 25648a6..2e4767e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## master
 
+- Report order.user_id as customer_id when calculating taxes and creating transactions. This enables the use of per customer exemptions.
+
 ## v0.12.0
 
 - Report no tax collected on order and line items when order total zeroed out.
diff --git a/lib/super_good/solidus_taxjar/api_params.rb b/lib/super_good/solidus_taxjar/api_params.rb
index 53b2c81..7c6942f 100644
--- a/lib/super_good/solidus_taxjar/api_params.rb
+++ b/lib/super_good/solidus_taxjar/api_params.rb
@@ -4,6 +4,7 @@ module SuperGood
       class << self
         def order_params(order)
           {}
+            .merge(customer_params(order))
             .merge(order_address_params(order.tax_address))
             .merge(line_items_params(order.line_items))
             .merge(shipping: order.shipment_total)
@@ -23,6 +24,7 @@ module SuperGood
 
         def transaction_params(order)
           {}
+            .merge(customer_params(order))
             .merge(order_address_params(order.tax_address))
             .merge(transaction_line_items_params(order.line_items))
             .merge(
@@ -51,6 +53,12 @@ module SuperGood
 
         private
 
+        def customer_params(order)
+          return {} unless order.user_id
+
+          { customer_id: order.user_id.to_s }
+        end
+
         def order_address_params(address)
           {
             to_country: address.country.iso,
diff --git a/spec/super_good/solidus_taxjar/api_params_spec.rb b/spec/super_good/solidus_taxjar/api_params_spec.rb
index 0311ab4..9718b88 100644
--- a/spec/super_good/solidus_taxjar/api_params_spec.rb
+++ b/spec/super_good/solidus_taxjar/api_params_spec.rb
@@ -10,7 +10,8 @@ RSpec.describe SuperGood::SolidusTaxJar::APIParams do
       ship_address: ship_address,
       shipment_total: BigDecimal("3.01"),
       store: store,
-      total: order_total
+      total: order_total,
+      user_id: 12345
     ).tap do |order|
       order.update! completed_at: DateTime.new(2018, 3, 6, 12, 10, 33)
     end
@@ -123,6 +124,7 @@ RSpec.describe SuperGood::SolidusTaxJar::APIParams do
 
     it "returns params for fetching the tax for the order" do
       expect(subject).to eq(
+        customer_id: "12345",
         to_country: "US",
         to_zip: "90210",
         to_city: "Los Angeles",
@@ -154,6 +156,7 @@ RSpec.describe SuperGood::SolidusTaxJar::APIParams do
 
       it "excludes the line item" do
         expect(subject).to eq(
+          customer_id: "12345",
           to_country: "US",
           to_zip: "90210",
           to_city: "Los Angeles",
@@ -190,6 +193,7 @@ RSpec.describe SuperGood::SolidusTaxJar::APIParams do
     it "returns params for creating/updating an order transaction" do
       expect(subject).to eq({
        amount: BigDecimal("113.58"),
+       customer_id: "12345",
        sales_tax: BigDecimal("9.87"),
        shipping: BigDecimal("3.01"),
        to_city: "Los Angeles",
@@ -249,6 +253,7 @@ RSpec.describe SuperGood::SolidusTaxJar::APIParams do
       it "excludes the line item" do
         expect(subject).to eq({
          amount: BigDecimal("113.58"),
+         customer_id: "12345",
          sales_tax: BigDecimal("9.87"),
          shipping: BigDecimal("3.01"),
          to_city: "Los Angeles",