Handle interval where base is missing on older dates

.rubocop.yml

@@ -12,7 +12,7 @@ Metrics/BlockLength:
   ExcludedMethods: ['dataset_module', 'describe', 'helpers']
 
 Metrics/AbcSize:
-  Max: 20.62
+  Max: 21.79
 
 Metrics/MethodLength:
   Max: 13

lib/quote/base.rb

@@ -66,7 +66,7 @@ module Quote
       result.each do |date, rates|
         rates['EUR'] = amount if symbols.nil? || symbols.include?('EUR')
         divisor = rates.delete(base)
-        if rates.empty?
+        if divisor.nil? || rates.empty?
           result.delete(date)
         else
           result[date] = rates.sort

spec/edge_cases_spec.rb

@@ -28,14 +28,14 @@ describe 'the server' do
     last_response.must_be :not_found?
   end
 
-  it 'will not process an invalid base' do
+  it 'will not process an unavailable base' do
     get '/latest?base=UAH'
-    last_response.must_be :unprocessable?
+    last_response.must_be :not_found?
   end
 
   it 'handles malformed queries' do
     get '/latest?base=USD?callback=?'
-    last_response.must_be :unprocessable?
+    last_response.must_be :not_found?
   end
 
   it 'does not return stale dates' do

spec/helper.rb

@@ -6,6 +6,7 @@ require_relative '../config/environment'
 
 require 'minitest/autorun'
 require 'minitest/around/spec'
+require 'minitest/focus'
 require 'vcr'
 require 'webmock'
 

spec/quote/base_spec.rb

@@ -50,6 +50,27 @@ module Quote
       end
     end
 
+    describe 'when rebasing from an unavailable currency' do
+      let(:date) do
+        Date.parse('2000-01-01')
+      end
+
+      let(:quote) do
+        klass.new(date: date, base: 'ILS')
+      end
+
+      before do
+        def quote.fetch_data
+          [{ date: date, iso_code: 'USD', rate: 1 }]
+        end
+      end
+
+      it 'finds nothing' do
+        quote.perform
+        quote.not_found?.must_equal true
+      end
+    end
+
     describe 'when rebasing and converting to an unavailable currency' do
       let(:date) do
         Date.today
@@ -61,7 +82,7 @@ module Quote
 
       before do
         def quote.fetch_data
-          [{ date: date, iso_code: 'USD', rate: 1.2 }]
+          [{ date: date, iso_code: 'USD', rate: 1 }]
         end
       end