From f3657624ab13f811ebe186c9aa1d7ce6b3e91ce8 Mon Sep 17 00:00:00 2001
From: Ruben Ignacio Guzman Zamora <ruben.ignaciogz@gmail.com>
Date: Sat, 17 Jan 2026 15:43:50 -0500
Subject: [PATCH 1/4] Add separate methods for compute currency from iso code
 and symbol

---
 lib/monetize/parser.rb | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/lib/monetize/parser.rb b/lib/monetize/parser.rb
index 02a6b328f..6bd0d7061 100644
--- a/lib/monetize/parser.rb
+++ b/lib/monetize/parser.rb
@@ -73,14 +73,27 @@ def to_big_decimal(value)
     attr_reader :input, :fallback_currency, :options
 
     def parse_currency
-      computed_currency = nil
+      computed_currency = compute_currency_from_iso_code
+      computed_currency ||= compute_currency_from_symbol if assume_from_symbol?
+      computed_currency ||= fallback_currency || Money.default_currency
+
+      raise Money::Currency::UnknownCurrency unless computed_currency
+
+      computed_currency
+    end
+
+    def compute_currency_from_iso_code
       computed_currency = input[/[A-Z]{2,3}/]
-      computed_currency = nil unless Money::Currency.find(computed_currency)
-      computed_currency ||= compute_currency if assume_from_symbol?
 
-      found = computed_currency || fallback_currency || Money.default_currency
-      raise Money::Currency::UnknownCurrency unless found
-      found
+      return unless Money::Currency.find(computed_currency)
+
+      computed_currency
+    end
+
+    def compute_currency_from_symbol
+      match = input.match(CURRENCY_SYMBOL_REGEX)
+
+      CURRENCY_SYMBOLS[match.to_s] if match
     end
 
     def assume_from_symbol?
@@ -99,11 +112,6 @@ def apply_sign(negative, amount)
       negative ? amount * -1 : amount
     end
 
-    def compute_currency
-      match = input.match(CURRENCY_SYMBOL_REGEX)
-      CURRENCY_SYMBOLS[match.to_s] if match
-    end
-
     def extract_major_minor(num, currency)
       used_delimiters = num.scan(/[^\d]/).uniq
 

From 96ac50c8c2e16ecb89e4df858144d5bd5eda890a Mon Sep 17 00:00:00 2001
From: Ruben Ignacio Guzman Zamora <ruben.ignaciogz@gmail.com>
Date: Sat, 17 Jan 2026 19:12:03 -0500
Subject: [PATCH 2/4] Add methods to register, unregister, and reset currency
 symbols

---
 lib/monetize.rb        | 12 +++++++++
 lib/monetize/parser.rb | 49 +++++++++++++++++++++++++++++--------
 spec/monetize_spec.rb  | 55 ++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 104 insertions(+), 12 deletions(-)

diff --git a/lib/monetize.rb b/lib/monetize.rb
index 1ec63d360..ca5e3eec1 100644
--- a/lib/monetize.rb
+++ b/lib/monetize.rb
@@ -68,5 +68,17 @@ def from_numeric(value, currency = Money.default_currency)
       fail ArgumentError, "'value' should be a type of Numeric" unless value.is_a?(Numeric)
       Money.from_amount(value, currency)
     end
+
+    def register_currency_symbol(symbol, iso_code)
+      Monetize::Parser.register_currency_symbol(symbol, iso_code)
+    end
+
+    def unregister_currency_symbol(symbol)
+      Monetize::Parser.unregister_currency_symbol(symbol)
+    end
+
+    def reset_currency_symbols!
+      Monetize::Parser.reset_currency_symbols!
+    end
   end
 end
diff --git a/lib/monetize/parser.rb b/lib/monetize/parser.rb
index 6bd0d7061..c842f227e 100644
--- a/lib/monetize/parser.rb
+++ b/lib/monetize/parser.rb
@@ -1,6 +1,12 @@
 module Monetize
   class Parser
-    CURRENCY_SYMBOLS = {
+    MULTIPLIER_SUFFIXES = { 'K' => 3, 'M' => 6, 'B' => 9, 'T' => 12 }
+    MULTIPLIER_SUFFIXES.default = 0
+    MULTIPLIER_REGEXP = /^(.*?\d)(#{MULTIPLIER_SUFFIXES.keys.join('|')})\b([^\d]*)$/i
+
+    DEFAULT_DECIMAL_MARK = '.'.freeze
+
+    @@original_currency_symbols = {
       '$'  => 'USD',
       '€'  => 'EUR',
       '£'  => 'GBP',
@@ -26,15 +32,38 @@ class Parser
       'S$' => 'SGD',
       'HK$'=> 'HKD',
       'NT$'=> 'TWD',
-      '₱'  => 'PHP',
-    }
+      '₱'  => 'PHP'
+    }.freeze
 
-    CURRENCY_SYMBOL_REGEX = /(?<![A-Z])(#{CURRENCY_SYMBOLS.keys.map { |key| Regexp.escape(key) }.join('|')})(?![A-Z])/i
-    MULTIPLIER_SUFFIXES = { 'K' => 3, 'M' => 6, 'B' => 9, 'T' => 12 }
-    MULTIPLIER_SUFFIXES.default = 0
-    MULTIPLIER_REGEXP = Regexp.new(format('^(.*?\d)(%s)\b([^\d]*)$', MULTIPLIER_SUFFIXES.keys.join('|')), 'i')
+    class << self
+      def currency_symbols
+        @@currency_symbols ||= @@original_currency_symbols.dup
+      end
 
-    DEFAULT_DECIMAL_MARK = '.'.freeze
+      def register_currency_symbol(symbol, iso_code)
+        @@currency_symbols[symbol] = iso_code
+
+        reset_currency_symbol_regex
+      end
+
+      def unregister_currency_symbol(symbol)
+        @@currency_symbols.delete(symbol)
+        reset_currency_symbol_regex
+      end
+
+      def reset_currency_symbols!
+        @@currency_symbols = @@original_currency_symbols.dup
+        reset_currency_symbol_regex
+      end
+
+      def currency_symbol_regex
+        @@currency_symbol_regex ||= /(?<![A-Z])(#{currency_symbols.keys.map { |key| Regexp.escape(key) }.join('|')})(?![A-Z])/i
+      end
+
+      def reset_currency_symbol_regex
+        @@currency_symbol_regex = nil
+      end
+    end
 
     def initialize(input, fallback_currency = Money.default_currency, options = {})
       @input = input.to_s.strip
@@ -91,9 +120,9 @@ def compute_currency_from_iso_code
     end
 
     def compute_currency_from_symbol
-      match = input.match(CURRENCY_SYMBOL_REGEX)
+      match = input.match(self.class.currency_symbol_regex)
 
-      CURRENCY_SYMBOLS[match.to_s] if match
+      self.class.currency_symbols[match.to_s] if match
     end
 
     def assume_from_symbol?
diff --git a/spec/monetize_spec.rb b/spec/monetize_spec.rb
index de7c597c4..7b31df562 100644
--- a/spec/monetize_spec.rb
+++ b/spec/monetize_spec.rb
@@ -54,7 +54,7 @@
           Monetize.assume_from_symbol = false
         end
 
-        Monetize::Parser::CURRENCY_SYMBOLS.each_pair do |symbol, iso_code|
+        Monetize::Parser.currency_symbols.each_pair do |symbol, iso_code|
           context iso_code do
             let(:currency) { Money::Currency.find(iso_code) }
             let(:amount) { 5_95 }
@@ -132,6 +132,57 @@
             expect(Monetize.parse('kr9.99')).to eq Money.new(999, 'USD')
           end
         end
+
+        context "registered custom symbols and unregistering" do
+          after { Monetize.reset_currency_symbols! }
+
+          it "parses registered custom currency symbol" do
+            Monetize.register_currency_symbol("S/", "PEN")
+
+            expect(Monetize.parse("S/19.90")).to eq Money.new(1990, "PEN")
+          end
+
+          it "overrides existing currency symbol when registering" do
+            Monetize.register_currency_symbol("€", "USD")
+
+            expect(Monetize.parse("€19.90")).to eq Money.new(1990, "USD")
+          end
+
+          it "unregisters custom currency symbol" do
+            Monetize.register_currency_symbol("S/", "PEN")
+
+            expect(Monetize.parse("S/19.90")).to eq Money.new(1990, "PEN")
+
+            Monetize.unregister_currency_symbol("S/")
+
+            expect(Monetize.parse("S/19.90")).to eq Money.new(1990, "USD")
+          end
+
+          it "unregisters existing currency symbol" do
+            Monetize.unregister_currency_symbol("€")
+
+            expect(Monetize.parse("€19.90")).to eq Money.new(1990, "USD")
+          end
+
+          it "unregisters non-registered currency symbol without errors" do
+            expect {
+              Monetize.unregister_currency_symbol("XYZ")
+            }.not_to raise_error
+          end
+
+          it "resets currency symbols to original set" do
+            Monetize.register_currency_symbol("S/", "PEN")
+            Monetize.unregister_currency_symbol("€")
+
+            expect(Monetize.parse("S/19.90")).to eq Money.new(1990, "PEN")
+            expect(Monetize.parse("€19.90")).to eq Money.new(1990, "USD")
+
+            Monetize.reset_currency_symbols!
+
+            expect(Monetize.parse("€19.90")).to eq Money.new(1990, "EUR")
+            expect(Monetize.parse("S/19.90")).to eq Money.new(1990, "USD")
+          end
+        end
       end
 
       context 'opted out' do
@@ -172,7 +223,7 @@
         end
 
         it 'parses currency not in CURRENCY_SYMBOLS given as ISO code' do
-          expect(Monetize::Parser::CURRENCY_SYMBOLS).to_not have_value('DKK')
+          expect(Monetize::Parser.currency_symbols).to_not have_value('DKK')
           expect('20.00 DKK'.to_money).to eq Money.new(20_00, 'DKK')
         end
 

From e0e0d7d56de783657dd8cbdd601feb1b59de3eb6 Mon Sep 17 00:00:00 2001
From: Ruben Ignacio Guzman Zamora <ruben.ignaciogz@gmail.com>
Date: Sat, 17 Jan 2026 21:05:38 -0500
Subject: [PATCH 3/4] Use the accessor method in currency symbol registration

---
 lib/monetize/parser.rb |  4 ++--
 spec/monetize_spec.rb  | 10 ++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/lib/monetize/parser.rb b/lib/monetize/parser.rb
index c842f227e..7bf78050a 100644
--- a/lib/monetize/parser.rb
+++ b/lib/monetize/parser.rb
@@ -41,13 +41,13 @@ def currency_symbols
       end
 
       def register_currency_symbol(symbol, iso_code)
-        @@currency_symbols[symbol] = iso_code
+        currency_symbols[symbol] = iso_code
 
         reset_currency_symbol_regex
       end
 
       def unregister_currency_symbol(symbol)
-        @@currency_symbols.delete(symbol)
+        currency_symbols.delete(symbol)
         reset_currency_symbol_regex
       end
 
diff --git a/spec/monetize_spec.rb b/spec/monetize_spec.rb
index 7b31df562..a1a3ff470 100644
--- a/spec/monetize_spec.rb
+++ b/spec/monetize_spec.rb
@@ -148,6 +148,16 @@
             expect(Monetize.parse("€19.90")).to eq Money.new(1990, "USD")
           end
 
+          it "registers currency symbol before currency_symbols is accessed" do
+            Monetize::Parser.class_variable_set(:@@currency_symbols, nil)
+
+            expect {
+              Monetize.register_currency_symbol("S/", "PEN")
+            }.not_to raise_error
+
+            expect(Monetize.parse("S/19.90")).to eq Money.new(1990, "PEN")
+          end
+
           it "unregisters custom currency symbol" do
             Monetize.register_currency_symbol("S/", "PEN")
 

From 84db6dfd4e662a86028b176e874d0ff99d77d1c2 Mon Sep 17 00:00:00 2001
From: Ruben Ignacio Guzman Zamora <ruben.ignaciogz@gmail.com>
Date: Sun, 18 Jan 2026 17:52:47 -0500
Subject: [PATCH 4/4] Simplify currency computation from ISO code by directly
 returning the Money::Currency.find result

---
 lib/monetize/parser.rb | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/lib/monetize/parser.rb b/lib/monetize/parser.rb
index 7bf78050a..c1d3d96eb 100644
--- a/lib/monetize/parser.rb
+++ b/lib/monetize/parser.rb
@@ -112,11 +112,7 @@ def parse_currency
     end
 
     def compute_currency_from_iso_code
-      computed_currency = input[/[A-Z]{2,3}/]
-
-      return unless Money::Currency.find(computed_currency)
-
-      computed_currency
+      Money::Currency.find(input[/[A-Z]{2,3}/])
     end
 
     def compute_currency_from_symbol