Class: Ask::Tools::Shell::FileMutationQueue

Inherits:
Object
  • Object
show all
Defined in:
lib/ask/tools/shell/file_mutation_queue.rb

Overview

Queues file mutations and applies them atomically. Rollback on any failure — no partial writes.

queue = FileMutationQueue.new
queue.stage("path/to/file.rb", ->(content) {
  content.gsub("old", "new")
})
queue.apply!  # reads all staged files, applies transforms, writes back

Defined Under Namespace

Classes: ApplyError

Instance Method Summary collapse

Constructor Details

#initialize(operations: nil) ⇒ FileMutationQueue

Returns a new instance of FileMutationQueue.



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# File 'lib/ask/tools/shell/file_mutation_queue.rb', line 18

def initialize(operations: nil)
  @staged = []
  @operations = operations || DefaultEditOperations.new
end

Instance Method Details

#apply! ⇒ Array<Hash>

Apply all staged mutations atomically. Reads all files, applies transforms, then writes all back. If any write fails, all written files are rolled back to original.

Returns:

  • (Array<Hash>) —

    results with :path, :original_size, :new_size, :success

Raises:

  • (ApplyError) —

    if any mutation fails (after rollback)



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# File 'lib/ask/tools/shell/file_mutation_queue.rb', line 37

def apply!
  snapshots = []

  # Phase 1: read all files and apply transforms
  @staged.each do |entry|
    path = entry[:path]
    original = @operations.read_file(path)
    modified = entry[:block].call(original)
    snapshots << { path: path, original: original, modified: modified }
  end

  # Phase 2: write all files, track rollback info
  written = []
  begin
    snapshots.each do |s|
      @operations.write_file(s[:path], s[:modified])
      written << s[:path]
    end
  rescue => e
    # Rollback: restore originals for files we already wrote
    written.each do |path|
      snapshot = snapshots.find { |s| s[:path] == path }
      @operations.write_file(path, snapshot[:original]) if snapshot
    rescue => rb_e
      $stderr.puts "[FileMutationQueue] Rollback failed for #{path}: #{rb_e.message}"
    end
    raise ApplyError, "Mutation failed at #{e.class}: #{e.message}. Rolled back #{written.size} files."
  end

  snapshots.map do |s|
    { path: s[:path], original_size: s[:original].length,
      new_size: s[:modified].length, success: true }
  end
end

#clear! ⇒ Object

Clear all staged mutations without applying.



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# File 'lib/ask/tools/shell/file_mutation_queue.rb', line 73

def clear!
  @staged.clear
end

#size ⇒ Object

Number of staged mutations.



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# File 'lib/ask/tools/shell/file_mutation_queue.rb', line 78

def size
  @staged.size
end

#stage(path) {|content| ... } ⇒ Object

Stage a mutation for a file.

Parameters:

  • path (String) —

    absolute path to the file

Yields:

  • (content) —

    raw file content, returns modified content

Yield Parameters:

  • content (String) —

    the original file content

Yield Returns:

  • (String) —

    the modified content



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# File 'lib/ask/tools/shell/file_mutation_queue.rb', line 28

def stage(path, &block)
  @staged << { path: File.expand_path(path), block: block }
end