From ae5c25d55bf96a0b7de78d2141f33e2ab0f6bfac Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 16 Dec 2024 17:10:22 +0000
Subject: [PATCH 01/27] style: Renamed the `handle_error` method to
 `handle_exceptions`

---
 app/controllers/exceptions_controller.rb | 2 +-
 config/initializers/exceptions.rb        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/controllers/exceptions_controller.rb b/app/controllers/exceptions_controller.rb
index cba7da59..e0b9fc75 100644
--- a/app/controllers/exceptions_controller.rb
+++ b/app/controllers/exceptions_controller.rb
@@ -4,7 +4,7 @@
 class ExceptionsController < ApplicationController
   layout 'application'
 
-  def render_error
+  def handle_exceptions
     env = request.env
     exception = env['action_dispatch.exception']
     status_code = ActionDispatch::ExceptionWrapper.new(env, exception).status_code
diff --git a/config/initializers/exceptions.rb b/config/initializers/exceptions.rb
index b0de5388..48551584 100644
--- a/config/initializers/exceptions.rb
+++ b/config/initializers/exceptions.rb
@@ -3,5 +3,5 @@
 # Custom error handling via a Rack middleware action
 Rails.application.config.exceptions_app =
   lambda do |env|
-    ExceptionsController.action(:render_error).call(env)
+    ExceptionsController.action(:handle_exceptions).call(env)
   end

From 2e6b96cb8722beee65a02cb800fc18b9bb6c82ca Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 16 Dec 2024 17:11:03 +0000
Subject: [PATCH 02/27] fix: set any unmatched route to be redirected to
 handle_exception method

---
 config/routes.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/config/routes.rb b/config/routes.rb
index adf861e7..8a39efa3 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -15,4 +15,6 @@
   get 'doc/ukhpi', to: 'doc#ukhpi', as: 'ukhpi_doc'
   get 'doc/ukhpi-dsd', to: 'doc#ukhpi_dsd'
   get 'doc/ukhpi-user-guide', to: 'doc#ukhpi_user_guide'
+
+  get '*unmatched_route', to: 'exceptions#handle_exceptions'
 end

From e71919ebb4fe757586dc29143a03550f278aebd2 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 17 Dec 2024 12:27:55 +0000
Subject: [PATCH 03/27] fix: undefined method `user_selections' for an instance
 of Hash

checks for user_selections or passes in new, empty, user_selections to ensure the key is present
---
 app/controllers/browse_controller.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/controllers/browse_controller.rb b/app/controllers/browse_controller.rb
index 8b7f2a3e..d40408b7 100644
--- a/app/controllers/browse_controller.rb
+++ b/app/controllers/browse_controller.rb
@@ -60,7 +60,8 @@ def render_view_state(view_state)
     @view_state = view_state
     if view_state.respond_to?(:[]) && view_state[:error]
       Rails.logger.debug { "Application experienced an issue with this request: #{view_state}" } if Rails.env.development? # rubocop:disable Metrics/LineLength
-      render_request_error(@view_state.user_selections, :internal_server_error)
+      user_selections = view_state.respond_to?(:user_selections) ? view_state.user_selections : UserSelections.new
+      render_request_error(user_selections, :internal_server_error)
     else
       respond_to do |format|
         format.html

From 5d8b26f23b05e178467760b2d797ae0e4dfbc967 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 17 Dec 2024 12:29:08 +0000
Subject: [PATCH 04/27] style: updated comments

primarily disabling rubocop linting warnings but also adjusted a debugging phrase
---
 app/controllers/browse_controller.rb | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/app/controllers/browse_controller.rb b/app/controllers/browse_controller.rb
index d40408b7..eab20250 100644
--- a/app/controllers/browse_controller.rb
+++ b/app/controllers/browse_controller.rb
@@ -3,7 +3,7 @@
 # Controller for the main user experience of browsing the UKHPI statistics.
 # Usually the primary interaction will be via JavaScript and XHR, but we also
 # support non-JS access by setting browse preferences in the `edit` action.
-class BrowseController < ApplicationController
+class BrowseController < ApplicationController # rubocop:disable Metrics/ClassLength
   layout 'webpack_application'
 
   def show
@@ -56,10 +56,11 @@ def setup_view_state(user_selections)
     { user_selections: user_selections, error: e.message }
   end
 
+  # rubocop:disable Metrics/MethodLength, Metrics/LineLength
   def render_view_state(view_state)
     @view_state = view_state
     if view_state.respond_to?(:[]) && view_state[:error]
-      Rails.logger.debug { "Application experienced an issue with this request: #{view_state}" } if Rails.env.development? # rubocop:disable Metrics/LineLength
+      Rails.logger.debug { "UKHPI experienced an issue with this request: #{view_state}" } if Rails.env.development?
       user_selections = view_state.respond_to?(:user_selections) ? view_state.user_selections : UserSelections.new
       render_request_error(user_selections, :internal_server_error)
     else
@@ -69,6 +70,7 @@ def render_view_state(view_state)
       end
     end
   end
+  # rubocop:enable Metrics/MethodLength, Metrics/LineLength
 
   # Look at the `action` parameter, which may be set by various action buttons
   # on the form, to determine whether we need to do any processing before
@@ -108,7 +110,7 @@ def match_location(view_state)
   end
 
   def match_no_locations
-    flash[:search] = 'Sorry, no locations match that search term' # rubocop:disable Rails/I18nLocaleTexts
+    flash.now[:search] = 'Sorry, no locations match that search term' # rubocop:disable Rails/I18nLocaleTexts
   end
 
   def match_single_location(view_state, locations)
@@ -129,7 +131,7 @@ def view_result(view_state)
     }.merge(new_params))
   end
 
-  def render_request_error(user_selections, status)
+  def render_request_error(user_selections, status) # rubocop:disable Metrics/MethodLength
     respond_to do |format|
       @view_state = { user_selections: user_selections }
       request_status = status == 400 ? :bad_request : :internal_server_error

From b58b04275b8db9d3edd2bf96fb307e0935498c37 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 17 Dec 2024 12:29:37 +0000
Subject: [PATCH 05/27] style: disabled rubocop linting warning

---
 app/models/data_view.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/models/data_view.rb b/app/models/data_view.rb
index f2844e46..52e24037 100644
--- a/app/models/data_view.rb
+++ b/app/models/data_view.rb
@@ -7,7 +7,7 @@
 # a view of the  `averagePrice` indicator, together with the relevant dates,
 # location and other options, and access to the underlying data, to enable
 # the renderer to draw the display
-class DataView
+class DataView # rubocop:disable Metrics/ClassLength
   include Rails.application.routes.url_helpers
 
   attr_reader :user_selections, :query_result, :indicator, :theme

From 9e7afac5660838d4f23137d4c9517101c8a083e7 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 17 Dec 2024 12:31:21 +0000
Subject: [PATCH 06/27] fix: resolved duplicate element warnings on statistic
 view controls

by assigning unique names and id's to the checkboxes for each  row
---
 app/views/browse/_data_view.html.haml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/views/browse/_data_view.html.haml b/app/views/browse/_data_view.html.haml
index 8b8ffda4..3450a198 100644
--- a/app/views/browse/_data_view.html.haml
+++ b/app/views/browse/_data_view.html.haml
@@ -26,9 +26,10 @@
       %br
       %span.o-data-view__options-statistics
         - data_view.each_statistic do |stat|
+          - x = x ? x + 1 : 0
           %label
             - checked = data_view.statistic_selected?(stat)
-            %input{ type: 'checkbox', value: stat.slug, checked: checked }
+            %input{ id: "checkbox-#{node_id}-#{stat.slug}-#{x}", name: "checkbox-#{node_id}-#{stat.slug}", type: 'checkbox', value: stat.slug, checked: checked }
             %a{ href: data_view.add_remove_statistic(!checked, stat) }
               = stat.label
 

From cf8499803f87d1feca0c9277d5a74883d4934c10 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Wed, 18 Dec 2024 14:51:10 +0000
Subject: [PATCH 07/27] fix: check for slug before comparing to seeing if it's
 value is `vol`

---
 app/models/ukhpi_indicator.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/models/ukhpi_indicator.rb b/app/models/ukhpi_indicator.rb
index 72560cbf..02864d86 100644
--- a/app/models/ukhpi_indicator.rb
+++ b/app/models/ukhpi_indicator.rb
@@ -17,7 +17,7 @@ def initialize(slug, root_name, label_key)
 
   # @return True if this indicator denotes sales volume
   def volume?
-    slug == 'vol'
+    slug && slug == 'vol'
   end
 
   # @return The label for this indicator

From ba6a7ac6d230bdef80c42314a00e06b44d242f55 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Wed, 18 Dec 2024 15:41:38 +0000
Subject: [PATCH 08/27] Fix: casting long strings to `Date`, `Time` or
 `DateTime`

`ActiveModel::Type::Date` raises `ArgumentError` for strings longer than 128 characters; this rescues and logs if long string is attempted
---
 app/models/concerns/user_choices.rb | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/app/models/concerns/user_choices.rb b/app/models/concerns/user_choices.rb
index 7130e764..b9fcf301 100644
--- a/app/models/concerns/user_choices.rb
+++ b/app/models/concerns/user_choices.rb
@@ -54,15 +54,23 @@ def alternative_key(key)
   end
 
   # Recognise a date. Accepts ISO-8601 strings or Date objects.
-  # Dates that match YYYY-MM will be transformed to YYYY-MM-01.
   # @param date Either an ISO0-8601 date string, or a date object
   def parse_date(date)
     if date.is_a?(Date)
       date
     else
-      date_str = date.to_s.match?(/\d\d\d\d-(1[012]|0[1-9])/) ? "#{date}-01" : date.to_s
+      # We need to truncate the date to at most the final 10 characters expected
+      # to avoid potential errors from maliciously long strings.
+      potential_date = date.to_s.first(10)
+      # strings that match YYYY-MM will be transformed to YYYY-MM-01 (i.e. 10 chars)
+      date_str = potential_date.match?(/\d\d\d\d-(1[012]|0[1-9])/) ? "#{potential_date}-01" : potential_date
+      # We can now parse the date string and fail if it is not a valid date.
       Date.parse(date_str)
     end
+  rescue ArgumentError => e
+    # We use truncate here to show the original date value in the logs with an
+    # ellipsis but with a maximum length of 128 characters to clarify the error.
+    Rails.logger.error("Failed to parse date '#{date.to_s.truncate(128)}': #{e.message || e}")
   end
 
   def array_valued?(param)

From a26438281e517ac29e4e66fa45f3fa9fcf30b1e3 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Fri, 20 Dec 2024 13:00:01 +0000
Subject: [PATCH 09/27] style: disable line length warning from rubocop

---
 app/models/concerns/user_choices.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/models/concerns/user_choices.rb b/app/models/concerns/user_choices.rb
index b9fcf301..4bbdc3cf 100644
--- a/app/models/concerns/user_choices.rb
+++ b/app/models/concerns/user_choices.rb
@@ -63,7 +63,7 @@ def parse_date(date)
       # to avoid potential errors from maliciously long strings.
       potential_date = date.to_s.first(10)
       # strings that match YYYY-MM will be transformed to YYYY-MM-01 (i.e. 10 chars)
-      date_str = potential_date.match?(/\d\d\d\d-(1[012]|0[1-9])/) ? "#{potential_date}-01" : potential_date
+      date_str = potential_date.match?(/\d\d\d\d-(1[012]|0[1-9])/) ? "#{potential_date}-01" : potential_date # rubocop:disable Layout/LineLength
       # We can now parse the date string and fail if it is not a valid date.
       Date.parse(date_str)
     end

From 5280f14ca019589c85dad78532f74bc5c2de5111 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Fri, 20 Dec 2024 13:01:20 +0000
Subject: [PATCH 10/27] build: adds `meta_request` gem

Allows debugging via Chrome DevTools while in development
---
 Gemfile      | 3 ++-
 Gemfile.lock | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Gemfile b/Gemfile
index 267fdf37..f678e3ba 100644
--- a/Gemfile
+++ b/Gemfile
@@ -51,7 +51,8 @@ end
 group :development do
   # Access an IRB console on exception pages or by using <%= console %> in views
   gem 'web-console'
-
+  # Rails Panel is a Chrome extension for Rails development that will end your tailing of development.log.
+  gem 'meta_request'
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem 'spring'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 2ea53fd2..554d0e3b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -210,6 +210,9 @@ GEM
       net-smtp
     marcel (1.0.4)
     matrix (0.4.2)
+    meta_request (0.8.5)
+      rack-contrib (>= 1.1, < 3)
+      railties (>= 3.0.0, < 9)
     method_source (1.1.0)
     mini_mime (1.1.5)
     minitest (5.25.1)
@@ -266,6 +269,8 @@ GEM
       puma (>= 6.0)
     racc (1.8.1)
     rack (3.1.8)
+    rack-contrib (2.5.0)
+      rack (< 4)
     rack-proxy (0.7.7)
       rack
     rack-session (2.0.0)
@@ -475,6 +480,7 @@ DEPENDENCIES
   json_expressions
   json_rails_logger!
   m
+  meta_request
   minitest-rails
   minitest-reporters
   mocha

From 007b1444cec9a92053d6466622c461e75c7f34ed Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Fri, 20 Dec 2024 13:02:13 +0000
Subject: [PATCH 11/27] build: removed assets and start targets from server
 target in makefile

with intention being to manually include those targets when required
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 3934ec9a..f4cbec73 100644
--- a/Makefile
+++ b/Makefile
@@ -89,7 +89,7 @@ run: start
 	@if docker network inspect dnet > /dev/null 2>&1; then echo "Using docker network dnet"; else echo "Create docker network dnet"; docker network create dnet; sleep 2; fi
 	@docker run -p ${PORT}:3000 -e API_SERVICE_URL=${API_SERVICE_URL} --network dnet --rm --name ${SHORTNAME} ${NAME}:${TAG}
 
-server: assets start
+server:
 	@export SECRET_KEY_BASE=$(./bin/rails secret)
 	@API_SERVICE_URL=${API_SERVICE_URL} ./bin/rails server -p ${PORT}
 

From 7d8290a440e98a0409dcb00905ead4051a58aa28 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Fri, 20 Dec 2024 13:03:01 +0000
Subject: [PATCH 12/27] docs: updated CHANGELOG with unreleased changes

also includes a minor layout adjustment
---
 CHANGELOG.md | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7b5bc2e8..749a16e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changes to the UKHPI app by version and date
 
+## Unreleased
+
+- (Jon) Fix for casting long strings to `Date`, `Time` or `DateTime`
+
 ## 2.0.1 - 2024-12
 
 - (Jon) Improves error metrics reporting to ensure that logging always happens
@@ -23,7 +27,8 @@
 
 ## 1.8.0 - 2024-10
 
-- (Dan) Updates ruby version to 2.7.8 and alpine version to 3.16 [GH-455](https://github.com/epimorphics/ukhpi/issues/455)
+- (Dan) Updates ruby version to 2.7.8 and alpine version to 3.16
+  [GH-455](https://github.com/epimorphics/ukhpi/issues/455)
 
 ## 1.7.5 - 2024-09
 

From b6f895173ac8534c0b20770c2023dae2478548ea Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Fri, 20 Dec 2024 13:03:37 +0000
Subject: [PATCH 13/27] style: disabled rubocop warnings on test fixtures

---
 test/models/ukhpi_indicator_test.rb | 2 +-
 test/models/ukhpi_statistic_test.rb | 2 +-
 test/models/ukhpi_theme_test.rb     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/models/ukhpi_indicator_test.rb b/test/models/ukhpi_indicator_test.rb
index 5f26a7da..27bb2cec 100644
--- a/test/models/ukhpi_indicator_test.rb
+++ b/test/models/ukhpi_indicator_test.rb
@@ -4,7 +4,7 @@
 
 # Unit tests on the UkhpiIndicator class
 class UkhpiIndicatorTest < ActiveSupport::TestCase
-  describe 'UkhpiIndicator' do
+  describe 'UkhpiIndicator' do # rubocop:disable Metrics/BlockLength
     describe '#initialize' do
       it 'should provide access to the initialised values' do
         ind = UkhpiIndicator.new('foo', 'foo_root', 'average_price')
diff --git a/test/models/ukhpi_statistic_test.rb b/test/models/ukhpi_statistic_test.rb
index 1d8c3201..6b7593b7 100644
--- a/test/models/ukhpi_statistic_test.rb
+++ b/test/models/ukhpi_statistic_test.rb
@@ -4,7 +4,7 @@
 
 # Unit tests on the UkhpiStatistic class
 class UkhpiStatisticTest < ActiveSupport::TestCase
-  describe 'UkhpiStatistic' do
+  describe 'UkhpiStatistic' do # rubocop:disable Metrics/BlockLength
     describe '#initialize' do
       it 'should provide accessors to initialization state' do
         stat = UkhpiStatistic.new('foo', 'foo_r', 'all_property_types', true)
diff --git a/test/models/ukhpi_theme_test.rb b/test/models/ukhpi_theme_test.rb
index 7ee869a3..b4d791ba 100644
--- a/test/models/ukhpi_theme_test.rb
+++ b/test/models/ukhpi_theme_test.rb
@@ -4,7 +4,7 @@
 
 # Unit tests on the UkhpiTheme class
 class UkhpiThemeTest < ActiveSupport::TestCase
-  describe 'UkhpiTheme' do
+  describe 'UkhpiTheme' do # rubocop:disable Metrics/BlockLength
     describe '#initialize' do
       it 'should provide accessors to initialization state' do
         stat = stub

From d4999fa638d99c78b18bc0f0c32e17be871cbdd9 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 10:22:56 +0000
Subject: [PATCH 14/27] refactor: updated CHANGELOG to remove rolled back
 release header

---
 CHANGELOG.md | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 749a16e6..f8eca75e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,10 +2,8 @@
 
 ## Unreleased
 
-- (Jon) Fix for casting long strings to `Date`, `Time` or `DateTime`
-
-## 2.0.1 - 2024-12
-
+- (Jon) Fix for casting long strings to `Date`, `Time` or `DateTime` in Ruby
+  3.1.0
 - (Jon) Improves error metrics reporting to ensure that logging always happens
   with the appropriate severity depending on the exception status while reducing
   the types of errors that can trigger a an error metric and therefore a

From b6f638a57d4e010f13c6fb3ce3593431167154d4 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:15:48 +0000
Subject: [PATCH 15/27] fix: remove exceptions controller and intializer

to ensure the appropriate error message is handled correctly by the application
---
 app/controllers/exceptions_controller.rb | 31 ------------------------
 config/initializers/exceptions.rb        |  7 ------
 2 files changed, 38 deletions(-)
 delete mode 100644 app/controllers/exceptions_controller.rb
 delete mode 100644 config/initializers/exceptions.rb

diff --git a/app/controllers/exceptions_controller.rb b/app/controllers/exceptions_controller.rb
deleted file mode 100644
index 11c20945..00000000
--- a/app/controllers/exceptions_controller.rb
+++ /dev/null
@@ -1,31 +0,0 @@
-# frozen_string_literal: true
-
-# Controller to handle dynamically displaying error messages
-class ExceptionsController < ApplicationController
-  layout 'application'
-
-  def render_error
-    env = request.env
-    exception = env['action_dispatch.exception']
-    status_code = ActionDispatch::ExceptionWrapper.new(env, exception).status_code
-
-    sentry_code = maybe_report_to_sentry(exception, status_code)
-    # add the exception to the prometheus metrics
-    instrument_internal_error(exception)
-
-    render :error_page,
-           locals: { status: status_code, sentry_code: sentry_code },
-           layout: true,
-           status: status_code
-  end
-
-  private
-
-  def maybe_report_to_sentry(exception, status_code)
-    return nil if Rails.env.development? # Why are we reporting to Senty in dev?
-    return nil unless status_code >= 500
-
-    sevent = Sentry.capture_exception(exception)
-    sevent&.event_id
-  end
-end
diff --git a/config/initializers/exceptions.rb b/config/initializers/exceptions.rb
deleted file mode 100644
index b0de5388..00000000
--- a/config/initializers/exceptions.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-# frozen_string_literal: true
-
-# Custom error handling via a Rack middleware action
-Rails.application.config.exceptions_app =
-  lambda do |env|
-    ExceptionsController.action(:render_error).call(env)
-  end

From e9c62ed37b46b5d7a1d6b11928f26e0a1b3bf3bd Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:17:41 +0000
Subject: [PATCH 16/27] refactor: implement updated `instrument_internal_error`
 method

Notify subscriber(s) of an internal error event with the payload of the exception once done but only if error status is over 500
---
 app/controllers/application_controller.rb | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 34285f77..c45ab2cd 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -74,7 +74,26 @@ def detailed_request_log(duration)
   # @param [Exception] exp the exception that caused the error
   # @return [ActiveSupport::Notifications::Event] provides an object-oriented
   # interface to the event
-  def instrument_internal_error(exception)
-    ActiveSupport::Notifications.instrument('internal_error.application', exception: exception)
+  # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/MethodLength
+  def instrument_internal_error(exc, status = nil)
+    err = {
+      message: exc&.message || exc,
+      status: Rack::Utils::SYMBOL_TO_STATUS_CODE[exc]
+    }
+    err[:status] = status if status
+    err[:type] = exc.class&.name if exc&.class
+    err[:cause] = exc&.cause if exc&.cause
+    err[:backtrace] = exc&.backtrace if exc&.backtrace && Rails.env.development?
+    # Log the exception to the Rails logger with the appropriate severity
+    Rails.logger.send(err[:status] < 500 ? :warn : :error, JSON.generate(err))
+    # Return unless the status code is 500 or greater to ensure subscribers are NOT notified
+    return nil unless err[:status] >= 500
+
+    sevent = Sentry.capture_exception(exc) unless Rails.env.development?
+    # Instrument the internal error event to notify subscribers of the error
+    ActiveSupport::Notifications.instrument('internal_error.application', exception: err)
+    # Return the event id for the internal error event
+    sevent&.event_id
   end
+  # rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/MethodLength
 end

From dffe863fc0fd3741f50e26cec9eb411c3b2ea2e0 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:22:53 +0000
Subject: [PATCH 17/27] refactor: ensure correct error response is presented

also lists any errors based on current query as well as improves the contact information presentation
---
 app/views/exceptions/error_page.html.haml | 35 ++++++++++++-----------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/app/views/exceptions/error_page.html.haml b/app/views/exceptions/error_page.html.haml
index e27f6e64..6933d242 100644
--- a/app/views/exceptions/error_page.html.haml
+++ b/app/views/exceptions/error_page.html.haml
@@ -1,3 +1,6 @@
+- puts "Rendering error page with status: #{status.inspect}" if Rails.env.development?
+- puts "View state: #{@view_state.inspect}" if Rails.env.development?
+
 %article.u-clear
   - if status == 400
     %h1.o-heading--1 Request not understood
@@ -7,16 +10,16 @@
       message as a result of using the HPI or PPD applications, please let us
       know so that we can correct the problem.
 
-    - if @view_state.user_selections&.errors
+    - if @view_state && @view_state[:user_selections].errors.any?
       %p
         The following issues were identified in your request:
 
       %ul.list.list-bullet
-        - @view_state.user_selections.errors.each do |err_msg|
+        - @view_state[:user_selections].errors.each do |err_msg|
           %li
             = err_msg
 
-  - elsif status == 404
+  - if status == 404
     %h1.o-heading--1 Page not found
 
     %p
@@ -24,7 +27,7 @@
       Please check the spelling of the page address (URL). If you require further
       assistance, please see the contact details below.
 
-  - else
+  - if status == 500
     %h1.o-heading--1 Application error
 
     %p
@@ -42,16 +45,14 @@
         = sentry_code
 
   %h2.o-heading--2 Who to contact
-  %p
-    If you are unable to access the data, please
-    %a{ href: 'http://site.landregistry.gov.uk/contact-us/form' }
-      fill in our contact form.
-
-  %p
-    For general transaction data enquiries, email
-    %a{ href: 'mailto:DRO@landregistry.gov.uk' }
-      DRO@landregistry.gov.uk
-
-  %p
-    For general price paid data enquiries, contact
-    = mail_to(Rails.application.config.contact_email_address)
+  %ul.list.list-bullet
+    %li
+      If you are unable to access the data, please
+      %a{ href: '//site.landregistry.gov.uk/contact-us/form' }
+        fill in our contact form.
+    %li
+      For general transaction data enquiries, email
+      = mail_to('DRO@landregistry.gov.uk')
+    %li
+      For general price paid data enquiries, contact
+      = mail_to(Rails.application.config.contact_email_address)

From 97451b9135c023eea673f029725e3f190fa97adc Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:23:42 +0000
Subject: [PATCH 18/27] fix: better error control

Handle specific types of exceptions and render the appropriate error page or attempt to render a generic error page if no specific error page exists
---
 app/controllers/application_controller.rb | 72 +++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index c45ab2cd..e721666b 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -2,6 +2,8 @@
 
 # :nodoc:
 class ApplicationController < ActionController::Base
+  include Rails.application.routes.url_helpers
+  include ActionView::Helpers::TranslationHelper
   # Prevent CSRF attacks by raising an exception.
   # For APIs, you may want to use :null_session instead.
   protect_from_forgery with: :exception
@@ -37,6 +39,76 @@ def log_request_result
     detailed_request_log(duration)
   end
 
+  # Handle specific types of exceptions and render the appropriate error page
+  # or attempt to render a generic error page if no specific error page exists
+  unless Rails.application.config.consider_all_requests_local
+    rescue_from StandardError do |e|
+      # Trigger the appropriate error handling method based on the exception
+      case e.class
+      when ActionController::RoutingError, ActionView::MissingTemplate
+        :render404
+      when ActionController::InvalidCrossOriginRequest
+        :render403
+      when ActionController::BadRequest, ActionController::ParameterMissing
+        :render400
+      else
+        :handle_internal_error
+      end
+    end
+  end
+
+  # Render the appropriate error page based on the exception
+  def handle_internal_error(exception)
+    if exception.instance_of? ArgumentError
+      render_error(400)
+    else
+      Rails.logger.warn "No explicit error page for exception #{exception} - #{exception.class}"
+      # Instrument ActiveSupport::Notifications for internal server errors only:
+      sentry_code = instrument_internal_error(exception)
+      render_error(500, sentry_code)
+    end
+  end
+
+  def render_400(_exception = nil) # rubocop:disable Naming/VariableNumber
+    render_error(400)
+  end
+
+  def render_403(_exception = nil) # rubocop:disable Naming/VariableNumber
+    render_error(403)
+  end
+
+  def render_404(_exception = nil) # rubocop:disable Naming/VariableNumber
+    render_error(404)
+  end
+
+  def render_500(_exception = nil) # rubocop:disable Naming/VariableNumber
+    render_error(500)
+  end
+
+  def render_error(status, sentry_code = nil) # rubocop:disable Metrics/AbcSize
+    reset_response
+
+    status = Rack::Utils::SYMBOL_TO_STATUS_CODE[status] if status.is_a?(Symbol)
+    @view_state ||= LandingState.new(UserLanguageSelection.new(params))
+
+    respond_to do |format|
+      format.html { render_html_error_page(status, sentry_code) }
+      # Anything else returns the status as human readable plain string
+      format.all { render plain: Rack::Utils::HTTP_STATUS_CODES[status].to_s, status: status }
+    end
+  end
+
+  def render_html_error_page(status, sentry_code) # rubocop:disable Metrics/MethodLength
+    render 'exceptions/error_page',
+           locals: { status: status, sentry_code: sentry_code },
+           layout: true,
+           status: status
+  end
+
+  def reset_response
+    self.response_body = nil
+  end
+
   private
 
   # rubocop:disable Metrics/AbcSize

From 70f98c68538faeb688a975cb6d73e417703584fb Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:29:31 +0000
Subject: [PATCH 19/27] refactor: updated `render_request_error`

Converts status code to integer if it is a symbol alongside passing the status_code value to ensure the proper error message is displayed
---
 app/controllers/browse_controller.rb | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/app/controllers/browse_controller.rb b/app/controllers/browse_controller.rb
index eab20250..f3ff76a2 100644
--- a/app/controllers/browse_controller.rb
+++ b/app/controllers/browse_controller.rb
@@ -10,7 +10,7 @@ def show
     user_selections = UserSelections.new(params)
 
     if !user_selections.valid?
-      render_request_error(user_selections, 400)
+      render_request_error(user_selections, :bad_request)
     elsif explain_non_json?(user_selections)
       redirect_to_html_view(user_selections)
     else
@@ -56,13 +56,11 @@ def setup_view_state(user_selections)
     { user_selections: user_selections, error: e.message }
   end
 
-  # rubocop:disable Metrics/MethodLength, Metrics/LineLength
   def render_view_state(view_state)
     @view_state = view_state
     if view_state.respond_to?(:[]) && view_state[:error]
-      Rails.logger.debug { "UKHPI experienced an issue with this request: #{view_state}" } if Rails.env.development?
-      user_selections = view_state.respond_to?(:user_selections) ? view_state.user_selections : UserSelections.new
-      render_request_error(user_selections, :internal_server_error)
+      Rails.logger.debug { "Application experienced an issue with this request: #{view_state}" } if Rails.env.development? # rubocop:disable Metrics/LineLength
+      render_request_error(@view_state.user_selections, :internal_server_error)
     else
       respond_to do |format|
         format.html
@@ -70,7 +68,6 @@ def render_view_state(view_state)
       end
     end
   end
-  # rubocop:enable Metrics/MethodLength, Metrics/LineLength
 
   # Look at the `action` parameter, which may be set by various action buttons
   # on the form, to determine whether we need to do any processing before
@@ -110,7 +107,7 @@ def match_location(view_state)
   end
 
   def match_no_locations
-    flash.now[:search] = 'Sorry, no locations match that search term' # rubocop:disable Rails/I18nLocaleTexts
+    flash[:search] = 'Sorry, no locations match that search term' # rubocop:disable Rails/I18nLocaleTexts
   end
 
   def match_single_location(view_state, locations)
@@ -131,19 +128,20 @@ def view_result(view_state)
     }.merge(new_params))
   end
 
-  def render_request_error(user_selections, status) # rubocop:disable Metrics/MethodLength
+  def render_request_error(user_selections, status_code) # rubocop:disable Metrics/MethodLength
+    # Convert status code to integer if it is a symbol
+    status_code = Rack::Utils::SYMBOL_TO_STATUS_CODE[status_code] if status_code.is_a?(Symbol)
     respond_to do |format|
-      @view_state = { user_selections: user_selections }
-      request_status = status == 400 ? :bad_request : :internal_server_error
+      @view_state ||= { user_selections: user_selections }
       format.html do
         render 'exceptions/error_page',
-               locals: { status: status, sentry_code: nil },
+               locals: { status: status_code, sentry_code: nil },
                layout: true,
-               status: request_status
+               status: status_code
       end
 
       format.json do
-        render(json: { status: 'request error' }, status: request_status)
+        render(json: { status: 'request error' }, status: status_code)
       end
     end
   end

From 2cbfa93d79d0385c4af4995ddcf8f625cf792375 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:36:50 +0000
Subject: [PATCH 20/27] refactor: handle differences in
 @view_state.user_selections

---
 app/views/common/_header.html.haml | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/app/views/common/_header.html.haml b/app/views/common/_header.html.haml
index a5256a23..0a14e1a9 100644
--- a/app/views/common/_header.html.haml
+++ b/app/views/common/_header.html.haml
@@ -32,12 +32,13 @@
   .o-secondary-banner
     - if Rails.application.config.welsh_language_enabled
       %nav.o-secondary-banner__lang-select{ 'aria-label' => 'language selector' }
-        - if @view_state.user_selections.english?
+        - user_selections = @view_state.respond_to?(:[]) ? @view_state[:user_selections] : @view_state.user_selections
+        - if user_selections.english?
           English
         - else
-          = link_to('English', @view_state.user_selections.alternative_language_params.params)
+          = link_to('English', user_selections.alternative_language_params.params)
         |
-        - if @view_state.user_selections.welsh?
+        - if user_selections.welsh?
           Cymraeg
         - else
-          = link_to('Cymraeg', @view_state.user_selections.alternative_language_params.params)
+          = link_to('Cymraeg', user_selections.alternative_language_params.params)

From 9bec514816f92b3ebac34869eabbf53821a129d6 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:37:34 +0000
Subject: [PATCH 21/27] build: set specific path for `unmatched_route` to
 `render_404` helper

---
 config/routes.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config/routes.rb b/config/routes.rb
index 8a39efa3..d679ca1f 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -16,5 +16,5 @@
   get 'doc/ukhpi-dsd', to: 'doc#ukhpi_dsd'
   get 'doc/ukhpi-user-guide', to: 'doc#ukhpi_user_guide'
 
-  get '*unmatched_route', to: 'exceptions#handle_exceptions'
+  get '*unmatched_route', to: 'application#render_404'
 end

From 8b5ba75abb0893fe46e6dc6273f25ed2e60c9c66 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 12:38:02 +0000
Subject: [PATCH 22/27] style: disabled rubocop warnings

---
 app/controllers/application_controller.rb | 8 ++++----
 app/controllers/compare_controller.rb     | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index e721666b..022c71af 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 # :nodoc:
-class ApplicationController < ActionController::Base
+class ApplicationController < ActionController::Base # rubocop:disable Metrics/ClassLength
   include Rails.application.routes.url_helpers
   include ActionView::Helpers::TranslationHelper
   # Prevent CSRF attacks by raising an exception.
@@ -111,7 +111,7 @@ def reset_response
 
   private
 
-  # rubocop:disable Metrics/AbcSize
+  # rubocop:disable Metrics/AbcSize, Metrics/MethodLength
   def detailed_request_log(duration)
     env = request.env
 
@@ -139,11 +139,11 @@ def detailed_request_log(duration)
       Rails.logger.info(JSON.generate(log_fields))
     end
   end
-  # rubocop:enable Metrics/AbcSize
+  # rubocop:enable Metrics/AbcSize, Metrics/MethodLength
 
   # Notify subscriber(s) of an internal error event with the payload of the
   # exception once done
-  # @param [Exception] exp the exception that caused the error
+  # @param [exc] exp the exception that caused the error
   # @return [ActiveSupport::Notifications::Event] provides an object-oriented
   # interface to the event
   # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/MethodLength
diff --git a/app/controllers/compare_controller.rb b/app/controllers/compare_controller.rb
index 4998baf9..a66da0ca 100644
--- a/app/controllers/compare_controller.rb
+++ b/app/controllers/compare_controller.rb
@@ -31,7 +31,7 @@ def render_print
     render 'compare/print', layout: 'print'
   end
 
-  def perform_query(user_compare_selections)
+  def perform_query(user_compare_selections) # rubocop:disable Metrics/MethodLength
     query_results = {}
     base_selection = UserSelections.new(
       __safe_params: {

From 6d963911cf8f3d813a9b4a96f1b77f5795fb5334 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Mon, 6 Jan 2025 13:15:44 +0000
Subject: [PATCH 23/27] docs: updated CHANGELOG

---
 CHANGELOG.md | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8eca75e..69022118 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 
 ## Unreleased
 
+- (Jon) Updated the `ApplicationController` to handle each error status
+  appropriately as well as ensure that the `instrument_internal_error` method is
+  called when an internal error is raised
+- (Jon) Updated the `instrument_internal_error` method to replace the
+  `maybe_report_to_sentry` method while reporting internal errors to the
+  Prometheus metrics only when necessary
+- (Jon) Removed the custom error handling by deleting the `ExceptionsController`
+  and the `exceptions` initialiser
 - (Jon) Fix for casting long strings to `Date`, `Time` or `DateTime` in Ruby
   3.1.0
 - (Jon) Improves error metrics reporting to ensure that logging always happens
@@ -9,11 +17,6 @@
   the types of errors that can trigger a an error metric and therefore a
   notification in slack
   [GH-149](https://github.com/epimorphics/hmlr-linked-data/issues/149)
-- (Jon) Updated the `maybe_report_to_sentry` method to call the
-  `instrument_internal_error` method for reporting internal errors to the
-  Prometheus metrics when necessary
-- (Jon) Renamed the `handle_error` method to `handle_exceptions` to better
-  reflect the method's purpose
 
 ## 2.0.0 - 2024-11
 

From 873ca46a5b109044352d7a1be90d31681c57e67f Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 7 Jan 2025 13:47:02 +0000
Subject: [PATCH 24/27] fix: use `if/elsif/else` in error page responses

to ensure a message is displayed at all times.
---
 app/views/exceptions/error_page.html.haml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/views/exceptions/error_page.html.haml b/app/views/exceptions/error_page.html.haml
index 6933d242..cfca09b2 100644
--- a/app/views/exceptions/error_page.html.haml
+++ b/app/views/exceptions/error_page.html.haml
@@ -19,7 +19,7 @@
           %li
             = err_msg
 
-  - if status == 404
+  - elsif status == 404
     %h1.o-heading--1 Page not found
 
     %p
@@ -27,7 +27,7 @@
       Please check the spelling of the page address (URL). If you require further
       assistance, please see the contact details below.
 
-  - if status == 500
+  - else
     %h1.o-heading--1 Application error
 
     %p

From 243b4ab7267d3214df0b56fba1a58d0fa033f04e Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 7 Jan 2025 13:49:53 +0000
Subject: [PATCH 25/27] docs: updated CHANGELOG

---
 CHANGELOG.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69022118..3bca022a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+- (Jon) Refactored UI code to use if/elsif/else in error page responses to
+  ensure a message is displayed at all times no matter what status is passed in
+  as per best practices
 - (Jon) Updated the `ApplicationController` to handle each error status
   appropriately as well as ensure that the `instrument_internal_error` method is
   called when an internal error is raised

From b93e32ebb79d5880dacdad6c88683a2d6df5c49b Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 7 Jan 2025 14:18:13 +0000
Subject: [PATCH 26/27] build: updated version patch cadence

---
 app/lib/version.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/lib/version.rb b/app/lib/version.rb
index da348ade..4d205e68 100644
--- a/app/lib/version.rb
+++ b/app/lib/version.rb
@@ -3,7 +3,7 @@
 module Version
   MAJOR = 2
   MINOR = 0
-  PATCH = 0
+  PATCH = 1
   SUFFIX = nil
   VERSION = "#{MAJOR}.#{MINOR}.#{PATCH}#{SUFFIX && ".#{SUFFIX}"}"
 end

From 2c22473df12e1c097db3dd1fbfb6d1504ba2bc66 Mon Sep 17 00:00:00 2001
From: "Jon R. Humphrey" <jon.humphrey@epimorphics.com>
Date: Tue, 7 Jan 2025 14:19:43 +0000
Subject: [PATCH 27/27] docs: updated CHANGELOG

Added update release version patch cadence with date stamp
---
 CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3bca022a..e3a5c143 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+## 2.0.1 - 2025-01
+
 - (Jon) Refactored UI code to use if/elsif/else in error page responses to
   ensure a message is displayed at all times no matter what status is passed in
   as per best practices