Update hard-coded currency UI with currency specific params (#488)

* Update hard-coded currency UI with currency specific params

* Rename extension methods to match currency option names; Move cents extension to numeric class extension

* Use currency's precision to show the cents part in accounts show page

---------

Co-authored-by: Sriram Krishnan <sriram@seafoodsouq.com>

app/views/accounts/show.html.erb

@@ -11,7 +11,7 @@
     <div class="flex items-center gap-3">
       <div class="relative cursor-not-allowed">
         <div class="flex items-center gap-2 px-3 py-2">
-          <span class="text-gray-900">USD $</span>
+          <span class="text-gray-900"><%= @account.original_currency %> <%= @account.original_currency.unit %></span>
           <%= lucide_icon("chevron-down", class: "w-5 h-5 text-gray-500") %>
         </div>
       </div>
@@ -29,9 +29,11 @@
         <p class="text-sm text-gray-500">Total Value</p>
         <%# TODO: Will need a better way to split a formatted monetary value into these 3 parts %>
         <p class="text-gray-900">
-          <span class="text-gray-500"><%= number_to_currency(@account.original_balance)[0] %></span>
-          <span class="text-xl font-medium"><%= number_with_delimiter(@account.original_balance.round) %></span>
-          <span class="text-gray-500">.<%= number_to_currency(@account.original_balance, precision: 2)[-2, 2] %></span>
+          <span class="text-gray-500"><%= @account.original_currency.unit %></span>
+          <span class="text-xl font-medium"><%= format_currency(@account.original_balance, precision: 0, unit: '') %></span>
+          <%- if @account.original_currency.precision.positive? -%>
+            <span class="text-gray-500"><%= @account.original_currency.separator %><%= @account.original_balance.cents(precision: @account.original_currency.precision) %></span>
+          <% end %>
         </p>
         <% if @balance_series.nil? %>
           <p class="text-sm text-gray-500">Data not available for the selected period</p>

config/initializers/constants.rb

@@ -12,7 +12,7 @@ CURRENCY_OPTIONS = Hash.new { |hash, key| hash[key] = default_currency_options.d
   "NZD": { unit: "NZ$", precision: 2, delimiter: ",", separator: "." },
   "AUD": { unit: "A$", precision: 2, delimiter: ",", separator: "." },
   "KRW": { unit: "₩", precision: 0, delimiter: ",", separator: "." },
-  "INR": { unit: "₹", precision: 0, delimiter: ",", separator: "." }
+  "INR": { unit: "₹", precision: 2, delimiter: ",", separator: "." }
 )
 
 EXCHANGE_RATE_ENABLED = ENV["OPEN_EXCHANGE_APP_ID"].present?

config/initializers/numeric_extensions.rb

@@ -0,0 +1,11 @@
+class Numeric
+  def cents(precision: 2)
+    return "" unless precision.positive?
+
+    cents = self.to_s.split(".")[1]
+    cents = "" unless cents.to_i.positive?
+
+    zero_padded_cents = cents.ljust(precision, "0")
+    zero_padded_cents[0..precision - 1]
+  end
+end

config/initializers/string_extensions.rb

@@ -0,0 +1,13 @@
+class String
+  def unit
+    CURRENCY_OPTIONS[self.to_sym][:unit]
+  end
+
+  def separator
+    CURRENCY_OPTIONS[self.to_sym][:separator]
+  end
+
+  def precision
+    CURRENCY_OPTIONS[self.to_sym][:precision]
+  end
+end

test/initializers/numeric_extensions_test.rb

@@ -0,0 +1,28 @@
+# test/initializers/big_decimal_extensions_test.rb
+require "test_helper"
+
+class NumericExtensionsTest < ActiveSupport::TestCase
+  test "#cents returns the cents part with 2 precisions by default" do
+    amount = 123.45
+    assert_equal "45", amount.cents
+  end
+
+  test "#cents returns empty when precision is 0" do
+    amount = 123.45
+    assert_equal "", amount.cents(precision: 0)
+  end
+
+  test "#cents returns the cents part of the string with given precision" do
+    amount = 123.4862
+    assert_equal "4", amount.cents(precision: 1)
+    assert_equal "486", amount.cents(precision: 3)
+  end
+
+  test "#cents pads the cents part with zeros up to the specified precision" do
+    amount_without_decimal = 123
+    amount_with_decimal = 123.4
+
+    assert_equal "00", amount_without_decimal.cents
+    assert_equal "40", amount_with_decimal.cents
+  end
+end

test/initializers/string_extensions_test.rb

@@ -0,0 +1,19 @@
+# test/string_extensions_test.rb
+require "test_helper"
+
+class StringExtensionsTest < ActiveSupport::TestCase
+  test "#unit returns the currency unit for a given currency code" do
+    assert_equal "$", "USD".unit
+    assert_equal "€", "EUR".unit
+  end
+
+  test "#separator returns the currency separator for a given currency code" do
+    assert_equal ".", "USD".separator
+    assert_equal ",", "EUR".separator
+  end
+
+  test "#precision returns the currency's precision for a given currency code" do
+    assert_equal 2, "USD".precision
+    assert_equal 0, "KRW".precision
+  end
+end