Modernize gem: Ruby 3.4, rubyzip 3.x fix, tests, and rubocop cleanup

.gitignore

@@ -5,3 +5,4 @@
 /stubs
 /vendor/bundle/
 /pkg
+.claude/

.rubocop.yml

@@ -1,23 +1,24 @@
 AllCops:
-  TargetRubyVersion: 2.7
+  TargetRubyVersion: 3.4
 
   # Include gemspec and Rakefile
   Include:
-    - '**/*.gemspec'
-    - '**/*.podspec'
-    - '**/*.jbuilder'
-    - '**/*.rake'
-    - '**/Gemfile'
-    - '**/Rakefile'
-    - '**/Capfile'
-    - '**/Guardfile'
-    - '**/Podfile'
-    - '**/Thorfile'
-    - '**/Vagrantfile'
+    - "**/*.rb"
+    - "**/*.gemspec"
+    - "**/*.podspec"
+    - "**/*.jbuilder"
+    - "**/*.rake"
+    - "**/Gemfile"
+    - "**/Rakefile"
+    - "**/Capfile"
+    - "**/Guardfile"
+    - "**/Podfile"
+    - "**/Thorfile"
+    - "**/Vagrantfile"
   Exclude:
-    - 'vendor/**/*'
-    - 'stubs/**/*'
-    - 'spec/support/shared_contexts/*'
+    - "vendor/**/*"
+    - "stubs/**/*"
+    - "spec/support/shared_contexts/*"
 
   NewCops: enable
 
@@ -51,6 +52,10 @@ Style/DoubleNegation:
 Style/PerlBackrefs:
   Enabled: false
 
+Style/OpenStructUse:
+  Exclude:
+    - "spec/**/*"
+
 ########################################
 # Lint Cops
 
@@ -66,6 +71,10 @@ Security/Eval:
 ########################################
 # Metrics Cops
 
+Metrics/BlockLength:
+  Exclude:
+    - "spec/**/*"
+
 Metrics/MethodLength:
   CountComments: false # count full line comments?
   Max: 30
@@ -77,7 +86,7 @@ Metrics/AbcSize:
   Enabled: false
 
 ########################################
-# Metrics Cops
+# Naming Cops
 
 Naming/FileName:
   Enabled: false

.ruby-version

@@ -1 +1 @@
-3.0.2
+3.4.8

CLAUDE.md

@@ -0,0 +1,89 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+A Ruby gem that downloads postal/zipcode data from GeoNames.org, processes it via an ETL pipeline, and outputs an SQLite3 database and optional CSV files. Supports single-country or all-countries processing.
+
+## Commands
+
+```bash
+# Install dependencies (vendored to vendor/bundle, binstubs in stubs/)
+bundle install
+
+# Run all tests
+bundle exec rspec
+
+# Run a single test file
+bundle exec rspec spec/path/to/file_spec.rb
+
+# Run a specific test by line number
+bundle exec rspec spec/path/to/file_spec.rb:42
+
+# Lint
+bundle exec rubocop
+
+# Lint with auto-correct
+bundle exec rubocop -a
+
+# Version bumping (do on develop branch, not master)
+bundle exec rake version:bump_patch
+bundle exec rake version:bump_minor
+bundle exec rake version:bump_major
+
+# Build and install gem
+bundle exec rake build
+bundle exec rake install
+
+# Release gem
+bundle exec rake release
+```
+
+## Architecture
+
+The gem follows an ETL (Extract, Transform, Load) pattern using the Kiba gem:
+
+1. **Extract**: `DataSource` downloads zip files from GeoNames.org, extracts them, and prepares CSV files with headers
+2. **Source**: `CsvSource` (Kiba source) feeds rows from the prepared CSV into the pipeline
+3. **Load**: Four Kiba destination table classes write rows into an in-memory SQLite database
+
+### Key Flow
+
+`bin/free_zipcode_data` → `Runner#start` → `DataSource#download` → `DataSource#datafile` (extract zip + add CSV headers) → `SqliteRam` (in-memory DB) → `ETL::FreeZipcodeDataJob` (Kiba pipeline) → `SqliteRam#save_to_disk`
+
+### Core Classes
+
+- **`FreeZipcodeData::Runner`** - CLI entry point; parses args via Optimist, orchestrates the full pipeline
+- **`FreeZipcodeData::DataSource`** - Downloads and extracts GeoNames zip files, prepares CSV with headers
+- **`SqliteRam`** - Wraps SQLite3; works entirely in-memory then saves to disk via `SQLite3::Backup`
+- **`FreeZipcodeData::DbTable`** - Base class for all table classes; provides progress bar, SQL helpers, and country lookup from `country_lookup_table.yml`
+- **`FreeZipcodeData::CountryTable`/`StateTable`/`CountyTable`/`ZipcodeTable`** - Kiba destinations; each has `build` (creates schema + indexes) and `write` (inserts rows, swallows duplicate constraint violations)
+- **`ETL::FreeZipcodeDataJob`** - Configures the Kiba pipeline with one source and four destinations
+- **`CsvSource`** - Kiba-compatible CSV reader
+
+### Singletons
+
+`Options` and `Logger` are singletons (via Ruby's `Singleton` module). `Runner` has an `.instance` convenience class method (returns `new` each time, not cached).
+
+## Configuration
+
+- `.ruby-version`: 3.4.8
+- Bundle path: `vendor/bundle` (binstubs in `stubs/`)
+- Environment: `APP_ENV` controls environment (`test`, `development`)
+- Config file: `~/.free_zipcode_data.yml` (overridable via `FZD_CONFIG_FILE` env var; uses `spec/fixtures/` version in test)
+
+## Rubocop
+
+Key style settings (`.rubocop.yml`):
+- Target Ruby 3.4
+- Max line length: 110
+- Max method length: 30 lines
+- `Style/ClassVars`, `Style/Documentation`, `Metrics/AbcSize`, `Lint/SuppressedException` disabled
+- `vendor/` and `stubs/` excluded
+
+## Git Workflow
+
+- `master` is the release branch
+- `develop` is the development branch
+- Version bumps should happen on `develop`, then merge to `master` before `rake release`

Gemfile

@@ -4,3 +4,13 @@ source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 gemspec
+
+group :development do
+  gem 'bundler'
+  gem 'pry-nav', '~> 0.2'
+  gem 'rake', '~> 13.0'
+  gem 'rspec', '~> 3.7'
+  gem 'rubocop'
+  gem 'ruby-prof', '~> 0.17'
+  gem 'simplecov', '~> 0.16'
+end

Gemfile.lock

@@ -3,7 +3,9 @@ PATH
   specs:
     free_zipcode_data (1.0.6)
       colored (~> 1.2)
+      csv
       kiba (~> 4.0)
+      logger
       optimist (~> 3.0)
       ruby-progressbar (~> 1.9)
       rubyzip (>= 1.2.2)
@@ -12,63 +14,75 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    ast (2.4.2)
+    ast (2.4.3)
     coderay (1.1.3)
     colored (1.2)
-    diff-lcs (1.4.4)
-    docile (1.4.0)
+    csv (3.3.5)
+    diff-lcs (1.6.2)
+    docile (1.4.1)
+    json (2.18.1)
     kiba (4.0.0)
+    language_server-protocol (3.17.0.5)
+    lint_roller (1.1.0)
+    logger (1.7.0)
     method_source (0.9.2)
     mini_portile2 (2.8.9)
     optimist (3.2.1)
-    parallel (1.21.0)
-    parser (3.0.2.0)
+    parallel (1.27.0)
+    parser (3.3.10.1)
       ast (~> 2.4.1)
+      racc
+    prism (1.9.0)
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     pry-nav (0.3.0)
       pry (>= 0.9.10, < 0.13.0)
-    rainbow (3.0.0)
-    rake (13.0.6)
-    regexp_parser (2.1.1)
-    rexml (3.4.2)
-    rspec (3.10.0)
-      rspec-core (~> 3.10.0)
-      rspec-expectations (~> 3.10.0)
-      rspec-mocks (~> 3.10.0)
-    rspec-core (3.10.1)
-      rspec-support (~> 3.10.0)
-    rspec-expectations (3.10.1)
+    racc (1.8.1)
+    rainbow (3.1.1)
+    rake (13.3.1)
+    regexp_parser (2.11.3)
+    rspec (3.13.2)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.6)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.5)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.10.0)
-    rspec-mocks (3.10.2)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.7)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.10.0)
-    rspec-support (3.10.3)
-    rubocop (1.22.3)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.7)
+    rubocop (1.84.2)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
       parallel (~> 1.10)
-      parser (>= 3.0.0.0)
+      parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml
-      rubocop-ast (>= 1.12.0, < 2.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.49.0, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.12.0)
-      parser (>= 3.0.1.1)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.49.0)
+      parser (>= 3.3.7.2)
+      prism (~> 1.7)
     ruby-prof (0.18.0)
-    ruby-progressbar (1.11.0)
-    rubyzip (3.1.1)
-    simplecov (0.21.2)
+    ruby-progressbar (1.13.0)
+    rubyzip (3.2.2)
+    simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
-    simplecov_json_formatter (0.1.3)
+    simplecov-html (0.13.2)
+    simplecov_json_formatter (0.1.4)
     sqlite3 (1.7.3)
       mini_portile2 (~> 2.8.0)
-    unicode-display_width (2.1.0)
+    unicode-display_width (3.2.0)
+      unicode-emoji (~> 4.1)
+    unicode-emoji (4.2.0)
 
 PLATFORMS
   ruby
@@ -84,4 +98,4 @@ DEPENDENCIES
   simplecov (~> 0.16)
 
 BUNDLED WITH
-   2.2.22
+   2.6.9

Rakefile

@@ -4,7 +4,7 @@ require 'rubygems'
 require 'bundler/setup'
 
 require 'rake'
-Dir['lib/tasks/**/*.rake'].sort.each { |ext| load ext }
+Dir['lib/tasks/**/*.rake'].each { |ext| load ext }
 
 # Install rubygem tasks
 Bundler::GemHelper.install_tasks

free_zipcode_data.gemspec

@@ -23,18 +23,12 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
-  spec.add_development_dependency 'bundler'
-  spec.add_development_dependency 'pry-nav', '~> 0.2'
-  spec.add_development_dependency 'rake', '~> 13.0'
-  spec.add_development_dependency 'rspec', '~> 3.7'
-  spec.add_development_dependency 'rubocop'
-  spec.add_development_dependency 'ruby-prof', '~> 0.17'
-  spec.add_development_dependency 'simplecov', '~> 0.16'
-
-  spec.add_runtime_dependency 'colored', '~> 1.2'
-  spec.add_runtime_dependency 'kiba', '~> 4.0'
-  spec.add_runtime_dependency 'optimist', '~> 3.0'
-  spec.add_runtime_dependency 'ruby-progressbar', '~> 1.9'
-  spec.add_runtime_dependency 'rubyzip', '>= 1.2.2'
-  spec.add_runtime_dependency 'sqlite3', '~> 1.3'
+  spec.add_dependency 'colored', '~> 1.2'
+  spec.add_dependency 'csv'
+  spec.add_dependency 'kiba', '~> 4.0'
+  spec.add_dependency 'logger'
+  spec.add_dependency 'optimist', '~> 3.0'
+  spec.add_dependency 'ruby-progressbar', '~> 1.9'
+  spec.add_dependency 'rubyzip', '>= 1.2.2'
+  spec.add_dependency 'sqlite3', '~> 1.3'
 end

lib/etl/common.rb

@@ -16,6 +16,7 @@ def show_me
 def limit(count)
   count = Integer(count || -1)
   return if count == -1
+
   transform do |row|
     @counter ||= 0
     @counter += 1

lib/etl/csv_source.rb

@@ -14,10 +14,10 @@ def initialize(filename:, headers: true, delimeter: "\t", quote_char: '"')
 
   def each
     CSV.open(filename,
-      col_sep: delimeter,
-      headers: headers,
-      header_converters: :symbol,
-      quote_char: quote_char) do |csv|
+             col_sep: delimeter,
+             headers: headers,
+             header_converters: :symbol,
+             quote_char: quote_char) do |csv|
       csv.each do |row|
         yield(row.to_hash)
       end

lib/free_zipcode_data.rb

@@ -14,16 +14,16 @@ def self.current_environment
     ENV.fetch('APP_ENV', 'development')
   end
 
-  #:nocov:
+  # :nocov:
   def self.config_file(filename = '.free_zipcode_data.yml')
     return root.join('spec', 'fixtures', filename) if current_environment == 'test'
 
-    home = ENV.fetch('HOME')
+    home = Dir.home
     file = ENV.fetch('FZD_CONFIG_FILE', File.join(home, '.free_zipcode_data.yml'))
     FileUtils.touch(file)
     file
   end
-  #:nocov:
+  # :nocov:
 
   def self.os
     if RUBY_PLATFORM.match?(/cygwin|mswin|mingw|bccwin|wince|emx/)