From b7155a5e35f85d32996154fbfd7c47e6d6115904 Mon Sep 17 00:00:00 2001
From: Geremia Taglialatela <tagliala.dev@gmail.com>
Date: Mon, 12 Aug 2024 09:39:25 +0200
Subject: [PATCH] Fix batch methods for historical models

In the default implementation, `cursor` defaults to `primary_key`, which
is 'id'.
However, for historical models, we need to use 'hid' instead of 'id'.

This patch addresses an issue where `with_hid_pkey` is called after the
cursor is already set, potentially leading to incorrect behavior.

Notes:
- `find_each` and `find_in_batches` use `in_batches` internally, however
  this is not enough anymore in the upcoming Rails 8.0 because there is
  a conditional branch using `enum_for`
- This approach prevents specifying 'id' as a cursor for historical
  models. If 'id' is needed, it must be handled separately.

Fix #321
---
 lib/chrono_model/patches/batches.rb | 36 ++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/lib/chrono_model/patches/batches.rb b/lib/chrono_model/patches/batches.rb
index debacbe..1acdb43 100644
--- a/lib/chrono_model/patches/batches.rb
+++ b/lib/chrono_model/patches/batches.rb
@@ -2,10 +2,44 @@
 
 module ChronoModel
   module Patches
+    # Overrides the default batch methods for historical models
+    #
+    # In the default implementation, `cursor` defaults to `primary_key`, which is 'id'.
+    # However, historical models need to use 'hid' instead of 'id'.
+    #
+    # This patch addresses an issue where `with_hid_pkey` is called after the cursor
+    # is already set, potentially leading to incorrect behavior.
+    #
+    # Notes:
+    # - `find_each` and `find_in_batches` internally utilize `in_batches`.
+    #   However, in the upcoming Rails 8.0, this implementation will be
+    #   insufficient due to a new conditional branch using `enum_for`.
+    # - This approach prevents specifying 'id' as a cursor for historical models.
+    #   If 'id' is needed, it must be handled separately.
+    #
+    # See: ifad/chronomodel#321 for more context
     module Batches
-      def in_batches(**)
+      def find_each(**options)
         return super unless try(:history?)
 
+        options[:cursor] = 'hid' if options[:cursor] == 'id'
+
+        with_hid_pkey { super }
+      end
+
+      def find_in_batches(**options)
+        return super unless try(:history?)
+
+        options[:cursor] = 'hid' if options[:cursor] == 'id'
+
+        with_hid_pkey { super }
+      end
+
+      def in_batches(**options)
+        return super unless try(:history?)
+
+        options[:cursor] = 'hid' if options[:cursor] == 'id'
+
         with_hid_pkey { super }
       end
     end