Keep Rails' parameter filtering working, and filter every value LogStruct logs

[ndbroadbent]

The first of twelve stacked PRs for 0.2.0. Merge them in order.

What this fixes

• Rails' filter_parameters stayed empty. LogStruct copied Rails' list into its own filters and then cleared it, so request.filtered_parameters, error reporters' parameter filters and Rails' request inspection stopped filtering. Setting component loggers at boot also loaded ActiveRecord::Base before the app's initializers, so filter_attributes was empty and inspected records showed passwords and tokens. Rails' list is now left alone, and the loggers are set from load hooks.
• Values deeper than the depth limit were logged raw (Values nested more than 20 levels deep are logged raw, skipping filtering and scrubbing #15), skipping filtering and scrubbing. They're now summarized (class and size), as is any value that raises while being processed.
• Rails' filters matched by exact name only. :passw didn't filter user_password. Symbols, Strings and Regexps now go through ActiveSupport::ParameterFilter, so they match what Rails matches. Partial matches don't apply to LogStruct's own top-level field names (Rails' default :_key would filter GoodJob's cron_key). Rails' filter blocks get copies of the key and value.
• Structs, ActionController::Parameters and other objects were serialized without filtering. The formatter now filters what as_json returns.
• Circular references (a Hash containing itself from two keys) took exponential time and produced huge lines. They're logged once.
• Verbose query logs are turned off on the ActiveRecord module, without loading ActiveRecord::Base.

Also pins json below 3 in the Rails test app (json 3 rejects an option ActiveSupport passes to it).

Addresses #15.

Testing

Every regression test fails without its fix. Sorbet and the unit suite (284 tests) pass at this branch's tip.

---

Stack for 0.2.0, merged in order: #16 → #17 → #18 → #19 → #20 → #21 → #22 → #23 → #24 → #25 → #26 → #27

Summary by CodeRabbit

• New Features

  • Rails parameter filters now also protect LogStruct logs. Filtered values remain masked as [FILTERED], and custom filters can still be configured.
  • Sensitive-data filtering now handles nested and circular values safely, with summaries when values cannot be processed.

• Documentation

  • Clarified how Rails filters match keys, how filter blocks are handled, and which LogStruct fields are affected.

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📥 Commits

Reviewing files that changed from the base of the PR and between a356c64 and e2a5bbd.

📒 Files selected for processing: 16

• .cspell/project-words.txt
• README.md
• docs/app/docs/filtering-sensitive-data/page.tsx
• lib/log_struct/concerns/configuration.rb
• lib/log_struct/config_struct/filters.rb
• lib/log_struct/formatter.rb
• lib/log_struct/integrations/action_mailer.rb
• lib/log_struct/integrations/active_record.rb
• lib/log_struct/param_filters.rb
• lib/log_struct/semantic_logger/setup.rb
• rails_test_app/create_app.rb
• rails_test_app/templates/test/integration/filter_parameters_test.rb
• test/log_struct/configuration_test.rb
• test/log_struct/formatter_test.rb
• test/log_struct/integrations/active_record_test.rb
• test/test_helper.rb

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