DEV: followup to 8edd2b38cb to use existing spec (#11830)

This commit also better explains in spec why max_values might be off by one.

spec/components/timeline_lookup_spec.rb

@@ -25,16 +25,19 @@ describe TimelineLookup do
     input = (1..100).map { |i| [1000 + i, 100 - i] }
 
     result = TimelineLookup.build(input, 5)
-    expect(result.size).to eq(5)
+    # even if max_value is 5 we might get 6 (5 + 1)
-    expect(result).to eq([[1, 99], [21, 79], [41, 59], [61, 39], [81, 19]])
+    # to ensure the last tuple is captured
+    expect(result).to eq([[1, 99], [21, 79], [41, 59], [61, 39], [81, 19], [input.size, input.last[1]]])
   end
 
   it "respects an uneven `max_values` setting" do
     input = (1..100).map { |i| [1000 + i, 100 - i] }
 
     result = TimelineLookup.build(input, 3)
-    expect(result.size).to eq(3)
+    # even if max_value is 3 we might get 4 (3 + 1)
-    expect(result).to eq([[1, 99], [35, 65], [69, 31]])
+    # to ensure the last tuple is captured
+    expect(result.size).to eq(4)
+    expect(result).to eq([[1, 99], [35, 65], [69, 31], [input.size, input.last[1]]])
   end
 
 end

spec/lib/timeline_lookup_spec.rb

@@ -1,17 +0,0 @@
-# frozen_string_literal: true
-
-require 'rails_helper'
-
-describe TimelineLookup do
-
-  context '.build' do
-    it 'keeps the last tuple in the lookup' do
-      tuples = [
-        [7173, 400], [7174, 390], [7175, 380], [7176, 370], [7177, 1]
-      ]
-
-      expect(TimelineLookup.build(tuples, 2)).to eq([[1, 400], [4, 370], [5, 1]])
-    end
-  end
-
-end