Hash filter params

app/models/filter.rb

@@ -10,7 +10,7 @@ class Filter < ApplicationRecord
       filter.save!
       filter
     rescue ActiveRecord::RecordNotUnique
-      find_by!(params: filter.params).tap(&:touch)
+      find_by!(params_digest: filter.hashed_params).tap(&:touch)
     end
   end
 

app/models/filter/params.rb

@@ -4,34 +4,28 @@ module Filter::Params
   KNOWN_PARAMS = [ :indexed_by, :assignments, bucket_ids: [], assignee_ids: [], tag_ids: [] ]
 
   included do
-    after_initialize :derive_params
+    before_save { self.params_digest = hashed_params }
+  end
+
+  def as_params
+    params = {}.tap do |h|
+      h["tag_ids"]      = tags.ids
+      h["bucket_ids"]   = buckets.ids
+      h["assignee_ids"] = assignees.ids
+      h["indexed_by"]   = indexed_by
+      h["assignments"]  = assignments
+    end
+
+    params.compact_blank.reject { |k, v| default_fields[k] == v }
   end
 
   def to_params
-    ActionController::Parameters.new(params).permit(*KNOWN_PARAMS).tap do |params|
+    ActionController::Parameters.new(as_params).permit(*KNOWN_PARAMS).tap do |params|
       params[:filter_id] = id if persisted?
     end
   end
 
-  private
-    # `derive_params` stores a denormalized version of the filter in `params` to
-    #    1) Enforce uniqueness via db constraints
-    #    2) Look up identical filters by a single column
-    #    3) Easily turn all filter params into a query string
-    def derive_params
-      derive_params_from_resource_ids
-      derive_params_from_fields
-      params.compact_blank!
-    end
-    alias_method :derived_params, :derive_params
-
-    def derive_params_from_resource_ids
-      params["tag_ids"] = tags.ids
-      params["bucket_ids"] = buckets.ids
-      params["assignee_ids"] = assignees.ids
-    end
-
-    def derive_params_from_fields
-      self.params.merge! fields.reject { |k, v| default_fields[k] == v }
-    end
+  def hashed_params
+    Digest::MD5.hexdigest as_params.to_json
+  end
 end

app/models/filter/resources.rb

@@ -10,6 +10,6 @@ module Filter::Resources
   def resource_removed(resource)
     kind = resource.class.model_name.plural
     send "#{kind}=", send(kind).without(resource)
-    derived_params.blank? ? destroy! : save!
+    as_params.blank? ? destroy! : save!
   end
 end

db/migrate/20241108205445_hash_filter_params.rb

@@ -0,0 +1,7 @@
+class HashFilterParams < ActiveRecord::Migration[8.0]
+  def change
+    change_column :filters, :params, :string, null: false
+    change_column_default :filters, :params, from: {}, to: nil
+    rename_column :filters, :params, :params_digest
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2024_11_05_224305) do
+ActiveRecord::Schema[8.0].define(version: 2024_11_08_205445) do
   create_table "accesses", force: :cascade do |t|
     t.integer "bucket_id", null: false
     t.integer "user_id", null: false
@@ -131,11 +131,11 @@ ActiveRecord::Schema[8.0].define(version: 2024_11_05_224305) do
 
   create_table "filters", force: :cascade do |t|
     t.integer "creator_id", null: false
-    t.json "params", default: {}, null: false
+    t.string "params_digest", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.json "fields", default: {}, null: false
-    t.index ["creator_id", "params"], name: "index_filters_on_creator_id_and_params", unique: true
+    t.index ["creator_id", "params_digest"], name: "index_filters_on_creator_id_and_params_digest", unique: true
   end
 
   create_table "filters_tags", id: false, force: :cascade do |t|

test/controllers/filters_controller_test.rb

@@ -28,6 +28,6 @@ class FiltersControllerTest < ActionDispatch::IntegrationTest
     assert_difference "users(:david).filters.count", -1 do
       delete filter_url(filters(:jz_assignments))
     end
-    assert_redirected_to bubbles_path(filters(:jz_assignments).params)
+    assert_redirected_to bubbles_path(filters(:jz_assignments).as_params)
   end
 end

test/fixtures/filters.yml

@@ -3,4 +3,4 @@ jz_assignments:
   tags: mobile
   assignees: jz
   fields: <%= { indexed_by: :most_discussed }.to_json %>
-  params: <%= { indexed_by: :most_discussed, tag_ids: [ ActiveRecord::FixtureSet.identify(:mobile) ], assignee_ids: [ ActiveRecord::FixtureSet.identify(:jz) ] }.to_json %>
+  params_digest: <%= Digest::MD5.hexdigest({ indexed_by: :most_discussed, tag_ids: [ ActiveRecord::FixtureSet.identify(:mobile) ], assignee_ids: [ ActiveRecord::FixtureSet.identify(:jz) ] }.to_json) %>

test/models/filter_test.rb

@@ -37,7 +37,7 @@ class FilterTest < ActiveSupport::TestCase
   test "param sanitization" do
     filter = users(:david).filters.new indexed_by: "most_active", tag_ids: "", assignee_ids: [ users(:jz).id ], bucket_ids: [ buckets(:writebook).id ]
     expected = { assignee_ids: [ users(:jz).id ], bucket_ids: [ buckets(:writebook).id ] }
-    assert_equal expected.stringify_keys, filter.params
+    assert_equal expected.stringify_keys, filter.as_params
   end
 
   test "cacheable" do
@@ -48,15 +48,15 @@ class FilterTest < ActiveSupport::TestCase
   test "resource removal" do
     filter = users(:david).filters.create! tag_ids: [ tags(:mobile).id ], bucket_ids: [ buckets(:writebook).id ]
 
-    assert_includes filter.params["tag_ids"], tags(:mobile).id
+    assert_includes filter.as_params["tag_ids"], tags(:mobile).id
     assert_includes filter.tags, tags(:mobile)
-    assert_includes filter.params["bucket_ids"], buckets(:writebook).id
+    assert_includes filter.as_params["bucket_ids"], buckets(:writebook).id
     assert_includes filter.buckets, buckets(:writebook)
 
     assert_changes "filter.reload.updated_at" do
       tags(:mobile).destroy!
     end
-    assert_nil filter.reload.params["tag_ids"]
+    assert_nil filter.reload.as_params["tag_ids"]
 
     assert_changes "Filter.exists?(filter.id)" do
       buckets(:writebook).destroy!