nanosecond_time_comparison.patch

From 2c6ea1df2198a25279f9d09832c901d42a41127c Mon Sep 17 00:00:00 2001
From: Jeff Wallace <[email protected]>
Date: Fri, 17 Jan 2014 14:12:18 -0800
Subject: [PATCH] Patch Time#== and Date#== to only check up to microsecond
 equality

---
 spec/lib/time_patch_spec.rb | 49 +++++++++++++++++++++++++++++++++++++++++++++
 spec/support/time_patch.rb  | 23 +++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 spec/lib/time_patch_spec.rb
 create mode 100644 spec/support/time_patch.rb

diff --git a/spec/lib/time_patch_spec.rb b/spec/lib/time_patch_spec.rb
new file mode 100644
index 0000000..1dd6c22
--- /dev/null
+++ b/spec/lib/time_patch_spec.rb
@@ -0,0 +1,49 @@
+require 'spec_helper'
+
+describe "Time patches" do
+
+  describe "for Time#==" do
+    let(:time1) { Time.at(0, 0.0) }
+    let(:time2) { Time.at(0, 0.5) }
+
+    it "ignores nanoseconds" do
+      expect(time1).to eq(time2)
+    end
+  end
+
+  describe "for ActiveSupport::TimeWithZone#==" do
+    let(:time1) { Time.at(0, 0.0).in_time_zone }
+    let(:time2) { Time.at(0, 0.5).in_time_zone }
+
+    it "ignores nanoseconds" do
+      expect(time1).to eq(time2)
+    end
+  end
+
+  describe "for DateTime#==" do
+    let(:date1) { DateTime.new(2000, 1, 1, 1, 1, Rational(1, 10000000)) }
+    let(:date2) { DateTime.new(2000, 1, 1, 1, 1, Rational(5, 10000000)) }
+
+    it "ignores nanoseconds" do
+      expect(date1).to eq(date2)
+    end
+  end
+
+  describe "for a mix of all 3 classes" do
+    let(:time1) { Time.utc(2000, 1, 1, 1, 1, 0, 0.0) }
+    let(:time2) { Time.utc(2000, 1, 1, 1, 1, 0, 0.5).in_time_zone }
+    let(:time3) { DateTime.new(2000, 1, 1, 1, 1, Rational(6, 10000000)) }
+
+    it "ignores nanoseconds" do
+      expect(time1).to eq(time2)
+      expect(time1).to eq(time3)
+
+      expect(time2).to eq(time1)
+      expect(time2).to eq(time3)
+
+      expect(time3).to eq(time1)
+      expect(time3).to eq(time2)
+    end
+  end
+
+end
diff --git a/spec/support/time_patch.rb b/spec/support/time_patch.rb
new file mode 100644
index 0000000..1f26a81
--- /dev/null
+++ b/spec/support/time_patch.rb
@@ -0,0 +1,23 @@
+# On linux (Circle CI) Time.now has nanosecond precision but on OSX it
+# only has microsecond precision. Postgresql stores time at microsecond
+# precision so timestamps generated in ruby (when creating a new record)
+# will not match what is stored in the database on linux.
+#
+# Also Time#to_f rounds up after using #end_of_day, so we have to use
+# the BigDecimal conversion.
+
+def _time_to_bigdecimal(time)
+  BigDecimal.new("#{time.to_i}.#{time.usec}")
+end
+
+class Time
+  def <=>(other_time)
+    _time_to_bigdecimal(self) <=> _time_to_bigdecimal(other_time)
+  end
+end
+
+class Date
+  def <=>(other_date)
+    self.to_time <=> other_date.to_time
+  end
+end
-- 
1.8.5.2