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Testing File Removal Operations in CarrierWave Uploader

This test suite examines the file removal functionality in CarrierWave’s uploader component. It verifies the proper cleanup of stored files, reset of file attributes, and handling of edge cases during file removal operations.

Test Coverage Overview

The test suite provides comprehensive coverage of the #remove! method in CarrierWave’s uploader.

Key areas tested include:

Path and URL reset verification
Cache status validation
Identifier cleanup
File deletion confirmation
Cache name reset
Empty file handling

Implementation Analysis

The testing approach utilizes RSpec’s let blocks and doubles for efficient test setup and isolation. The implementation employs mock objects to simulate storage engine interactions and file operations, allowing for controlled testing of the removal process without actual file system operations.

The tests leverage RSpec’s expectation syntax and before hooks for consistent test state management.

Technical Details

Testing tools and configuration:

RSpec as the testing framework
Double objects for mocking storage and file operations
FileUtils for cleanup operations
Custom uploader class inheritance from CarrierWave::Uploader::Base
Temporary file handling through CarrierWave’s cache system

Best Practices Demonstrated

The test suite exemplifies several testing best practices including proper test isolation, comprehensive edge case coverage, and efficient test setup.

Notable practices include:

Isolated test scenarios using RSpec doubles
Consistent cleanup in after blocks
Clear test descriptions
Focused unit tests for specific functionality
Proper exception handling verification

carrierwaveuploader/carrierwave

spec/uploader/remove_spec.rb

            
require 'spec_helper'

describe CarrierWave::Uploader do
  let(:uploader_class) { Class.new(CarrierWave::Uploader::Base) }
  let(:uploader) { uploader_class.new }
  let(:file_name) { 'test.jpg' }
  let(:file) { File.open(file_path(file_name)) }

  after { FileUtils.rm_rf(public_path) }

  describe '#remove!' do
    let(:stored_file) { double('a stored file') }

    before do
      allow(CarrierWave).to receive(:generate_cache_id).and_return('1390890634-26112-1234-2122')

      cached_file = double('a cached file')
      allow(cached_file).to receive(:delete)

      allow(stored_file).to receive(:path).and_return('/path/to/somewhere')
      allow(stored_file).to receive(:url).and_return('http://www.example.com')
      allow(stored_file).to receive(:identifier).and_return('this-is-me')
      allow(stored_file).to receive(:delete)

      storage = double('a storage engine')
      allow(storage).to receive(:store!).and_return(stored_file)
      allow(storage).to receive(:cache!).and_return(cached_file)
      allow(storage).to receive(:delete_dir!).with("uploads/tmp/#{CarrierWave.generate_cache_id}")
      allow(storage).to receive(:identifier).and_return(uploader.deduplicated_filename)

      allow(uploader_class.storage).to receive(:new).and_return(storage)
      uploader.store!(file)
    end

    it "resets the current path" do
      uploader.remove!
      expect(uploader.current_path).to be_nil
    end

    it "should not be cached" do
      uploader.remove!
      expect(uploader).not_to be_cached
    end

    it "resets the url" do
      uploader.cache!(file)
      uploader.remove!
      expect(uploader.url).to be_nil
    end

    it "resets the identifier" do
      uploader.remove!
      expect(uploader.identifier).to be_nil
    end

    it "deletes the file" do
      expect(stored_file).to receive(:delete)
      uploader.remove!
    end

    it "resets the cache_name" do
      uploader.cache!(file)
      uploader.remove!
      expect(uploader.cache_name).to be_nil
    end

    it "does nothing when trying to remove an empty file" do
      expect{ uploader.remove! }.not_to raise_error
    end
  end

end