Initial commit

spec/strike_me/btc_spec.rb

@@ -0,0 +1,108 @@
+# frozen_string_literal: true
+
+RSpec.describe StrikeMe::BTC do
+  context 'create from integer' do
+    it 'creates using #btc' do
+      btc = 314.btc
+
+      expect(btc).to be_a described_class
+      expect(btc.sats).to eq 314 * 100_000_000
+    end
+
+    it 'creates using #sats' do
+      btc = 314.sats
+
+      expect(btc).to be_a described_class
+      expect(btc.sats).to eq 314
+    end
+  end
+
+  context 'create from float' do
+    it 'creates using #btc' do
+      btc = 314.85.btc
+
+      expect(btc).to be_a described_class
+      expect(btc.sats).to eq 31_485_000_000
+    end
+
+    it 'creates using #sats' do
+      btc = 314.85.sats
+
+      expect(btc).to be_a described_class
+      expect(btc.sats).to eq 315
+    end
+  end
+
+  it 'properly formats to string' do
+    expect(described_class.new(234_522).to_s).to eq '0.00234522'
+  end
+
+  it 'formats properly in json structures' do
+    btc = described_class.new(234_522)
+    expect({ amount: btc }.to_json).to eq '{"amount":"0.00234522"}'
+  end
+
+  context 'arithmetic' do
+    it 'supports multiplication with numbers' do
+      btc1 = described_class.new(234_529)
+      btc2 = btc1 * 3
+      btc3 = btc2 * 2.9
+
+      expect(btc2).to be_a described_class
+      expect(btc3).to be_a described_class
+
+      expect(btc2).not_to eq btc1
+      expect(btc2).not_to eq btc3
+
+      expect(btc1.sats).to eq 234_529
+      expect(btc1).to eq  234_529
+      expect(btc2).to eq  703_587
+      expect(btc3).to eq 2_040_402
+    end
+
+    it 'supports division with numbers' do
+      btc1 = described_class.new(34_529)
+      btc2 = btc1 / 3
+      btc3 = btc2 / 2.9
+
+      expect(btc2).to be_a described_class
+      expect(btc3).to be_a described_class
+
+      expect(btc2).not_to eq btc1
+      expect(btc2).not_to eq btc3
+
+      expect(btc1.sats).to eq 34_529
+      expect(btc1).to eq      34_529
+      expect(btc2).to eq      11_509
+      expect(btc3).to eq 3_968
+    end
+
+    it 'supports addition with other BTC objects' do
+      btc1 = described_class.new(34_529)
+      btc2 = described_class.new(2_556)
+      btc3 = btc1 + btc2
+
+      expect { btc1 + 23 }.to raise_error StrikeMe::BTC::Error
+
+      expect(btc3).to be_a described_class
+      expect(btc3).to eq 37_085
+    end
+
+    it 'supports subtraction with other BTC objects' do
+      btc1 = described_class.new(34_529)
+      btc2 = described_class.new(2_556)
+      btc3 = btc1 - btc2
+
+      expect { btc1 - 23 }.to raise_error StrikeMe::BTC::Error
+
+      expect(btc3).to be_a described_class
+      expect(btc3).to eq 31_973
+    end
+  end
+
+  it 'is consistent for small values' do
+    string = 3.sats.to_s
+    expect(string).to eq '0.00000003'
+    expect(string.to_f.btc.sats).to eq 3
+  end
+end