From 0728f7488ae4f245e88d7412bb40b1cd1fa6a060 Mon Sep 17 00:00:00 2001
From: Alex Castillo <alex.castillog33@gmail.com>
Date: Tue, 8 Sep 2026 19:26:30 -0400
Subject: [PATCH 1/2] Default `Paginate#base_path` to "/" instead of nil

`base_path` is an optional keyword argument, but when it is omitted (or
passed as `nil`) and the collection spans more than one page, `next` and
`previous` build the path with `@base_path.sub(...)` and raise
`NoMethodError: undefined method 'sub' for nil`.

Default it to `"/"` (and coerce an explicit `nil`), so an omitted
`base_path` yields root-relative paths like `/page/2/` instead of
crashing. Callers that pass a `base_path` are unaffected.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GtYgwYNfJ3wHrw9xrooVoB
---
 lib/perron/paginate.rb       |  4 ++--
 test/perron/paginate_test.rb | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/lib/perron/paginate.rb b/lib/perron/paginate.rb
index 0fc7ef9..2ec63ac 100644
--- a/lib/perron/paginate.rb
+++ b/lib/perron/paginate.rb
@@ -2,10 +2,10 @@
 
 module Perron
   class Paginate
-    def initialize(collection, page:, per_page:, base_path: nil, page_path_template: nil, use_query_params: false)
+    def initialize(collection, page:, per_page:, base_path: "/", page_path_template: nil, use_query_params: false)
       @collection = collection
       @per_page = per_page
-      @base_path = base_path
+      @base_path = base_path || "/"
       @page_path_template = page_path_template || "/page/:page/"
       @use_query_params = use_query_params
 
diff --git a/test/perron/paginate_test.rb b/test/perron/paginate_test.rb
index c4c7333..6dec375 100644
--- a/test/perron/paginate_test.rb
+++ b/test/perron/paginate_test.rb
@@ -193,4 +193,22 @@ class Perron::PaginateTest < ActiveSupport::TestCase
 
     assert_equal "/articles/?page=2", paginate.previous
   end
+
+  test "next falls back to a root-relative path when base_path is omitted" do
+    paginate = Perron::Paginate.new((1..10).to_a, page: 1, per_page: 5)
+
+    assert_equal "/page/2/", paginate.next
+  end
+
+  test "previous falls back to root when base_path is omitted" do
+    paginate = Perron::Paginate.new((1..10).to_a, page: 2, per_page: 5)
+
+    assert_equal "/", paginate.previous
+  end
+
+  test "an explicit nil base_path is treated as root" do
+    paginate = Perron::Paginate.new((1..10).to_a, page: 1, per_page: 5, base_path: nil)
+
+    assert_equal "/page/2/", paginate.next
+  end
 end

From 8f5fcb5c24c56b94be0e33cc92473b8cb76340d4 Mon Sep 17 00:00:00 2001
From: Alex Castillo <alex.castillog33@gmail.com>
Date: Tue, 8 Sep 2026 19:34:02 -0400
Subject: [PATCH 2/2] Raise ArgumentError for a non-positive `per_page`

`config.pagination.per_page` has no default, so an unconfigured collection
reaches `Paginate.new(per_page: nil)` and dies with
`TypeError: nil can't be coerced into Float`. `per_page: 0` gives
`FloatDomainError: Infinity`, and a negative value gives
`ArgumentError: min argument must be smaller than max argument` from the
`clamp`. Validate up front with a message that says what is wrong.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GtYgwYNfJ3wHrw9xrooVoB
---
 lib/perron/paginate.rb       |  4 ++++
 test/perron/paginate_test.rb | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/lib/perron/paginate.rb b/lib/perron/paginate.rb
index 2ec63ac..a10b4a7 100644
--- a/lib/perron/paginate.rb
+++ b/lib/perron/paginate.rb
@@ -3,6 +3,10 @@
 module Perron
   class Paginate
     def initialize(collection, page:, per_page:, base_path: "/", page_path_template: nil, use_query_params: false)
+      unless per_page.is_a?(Integer) && per_page.positive?
+        raise ArgumentError, "per_page must be a positive integer, got #{per_page.inspect}"
+      end
+
       @collection = collection
       @per_page = per_page
       @base_path = base_path || "/"
diff --git a/test/perron/paginate_test.rb b/test/perron/paginate_test.rb
index 6dec375..4e2c10b 100644
--- a/test/perron/paginate_test.rb
+++ b/test/perron/paginate_test.rb
@@ -211,4 +211,14 @@ class Perron::PaginateTest < ActiveSupport::TestCase
 
     assert_equal "/page/2/", paginate.next
   end
+
+  test "raises ArgumentError for a non-positive or non-integer per_page" do
+    [0, -5, nil, 2.5].each do |bad|
+      error = assert_raises(ArgumentError) do
+        Perron::Paginate.new((1..10).to_a, page: 1, per_page: bad)
+      end
+
+      assert_match(/per_page must be a positive integer/, error.message)
+    end
+  end
 end