From 95599b2b9a4b424667c6272c2e73bf96c9311c72 Mon Sep 17 00:00:00 2001
From: Geremia Taglialatela <tagliala.dev@gmail.com>
Date: Sun, 17 Sep 2023 22:46:50 +0200
Subject: [PATCH] Cosmetic rewrite of string_to_utc_time method

- Add guard clauses
- Use format instead of sprintf (same performance)
- Disable `Style/PerlBackrefs` cop: it is the most performant way of
  implementing this method

NOTE: this implementation is 5x faster than `Time.parse`
---
 .rubocop_todo.yml               | 13 -------------
 lib/chrono_model/conversions.rb | 18 ++++++++----------
 2 files changed, 8 insertions(+), 23 deletions(-)

diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index f80b067..2f38e0c 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -98,20 +98,12 @@ Style/ExplicitBlockArgument:
     - 'lib/chrono_model/adapter/migrations.rb'
     - 'lib/chrono_model/time_machine/history_model.rb'
 
-# This cop supports safe autocorrection (--autocorrect).
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: format, sprintf, percent
-Style/FormatString:
-  Exclude:
-    - 'lib/chrono_model/conversions.rb'
-
 # This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: MinBodyLength, AllowConsecutiveConditionals.
 Style/GuardClause:
   Exclude:
     - 'lib/active_record/connection_adapters/chronomodel_adapter.rb'
     - 'lib/chrono_model/adapter/migrations.rb'
-    - 'lib/chrono_model/conversions.rb'
     - 'lib/chrono_model/time_machine.rb'
 
 # This cop supports unsafe autocorrection (--autocorrect-all).
@@ -162,11 +154,6 @@ Style/PercentLiteralDelimiters:
     - 'lib/chrono_model/time_machine/time_query.rb'
     - 'lib/chrono_model/time_machine/timeline.rb'
 
-# This cop supports safe autocorrection (--autocorrect).
-Style/PerlBackrefs:
-  Exclude:
-    - 'lib/chrono_model/conversions.rb'
-
 # This cop supports safe autocorrection (--autocorrect).
 Style/RedundantSelf:
   Exclude:
diff --git a/lib/chrono_model/conversions.rb b/lib/chrono_model/conversions.rb
index 0f223fa..f43d02b 100644
--- a/lib/chrono_model/conversions.rb
+++ b/lib/chrono_model/conversions.rb
@@ -6,20 +6,18 @@ module Conversions
 
     ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(?:\.(\d+))?\z/.freeze
 
+    # rubocop:disable Style/PerlBackrefs
     def string_to_utc_time(string)
       return string if string.is_a?(Time)
 
-      if string =~ ISO_DATETIME
-        # .1 is .100000, not .000001
-        usec =
-          if $7.nil?
-            '000000'
-          else
-            $7.ljust(6, '0')
-          end
-        Time.utc $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, usec.to_i
-      end
+      return unless string =~ ISO_DATETIME
+
+      # .1 is .100000, not .000001
+      usec = $7.ljust(6, '0') unless $7.nil?
+
+      Time.utc $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, usec.to_i
     end
+    # rubocop:enable Style/PerlBackrefs
 
     def time_to_utc_string(time)
       time.to_formatted_s(:db) << '.' << format('%06d', time.usec)