Forem: Andrey

Simple way to get all values from hash

Andrey — Tue, 17 Sep 2019 05:28:51 +0000

In the ruby from the box, we can't find all the hash values if it's nested.
I suggest an easy way to find all the values using recursion.

Example hash:

hash = {
  a: 2,
  b: { c: 3, d: 4, e: {f: 5}}
}

> hash.values
=> [2, {:c=>3, :d=>4, :e=>{:f=>5}}]

That's not an option, we need all the values.

def deep_values(array = [], object:)
  object.each do |_key, value|
    if value.is_a?(Hash)
      deep_values(array, object: value)
    else
      array << value
    end
  end
  array
end

> deep_values(object: hash)
=> [2, 3, 4, 5]

If you run the benchmark with this data, we get the following data:

>  puts Benchmark.measure { 100_000.times { hash.values } }
=> 0.028920   0.002643   0.031563 (  0.032759)

>  puts Benchmark.measure { 100_000.times { deep_values(object: hash ) } }
=> 0.140439   0.003318   0.143757 (  0.146637)

Git switch command

Andrey — Tue, 03 Sep 2019 19:20:02 +0000

A switch command has been added in the new version of git
Let's look at examples:

# switched to <branch>
git switch <branch>

# creates a new <branch>
git switch -c <branch>

# switched to commit 
git switch -d <commit> 

# creates and switches to branch from remote. 
# need to use if branch exists in multiple remotes 
git switch -c <branch> --track <remote>/<branch> 

# switch to a branch even if the index or working tree is different from HEAD
# this is used to throw away local changes
git switch --discard-changes <branch>

# alias for  --discard-changes
git switch -f <branch> 

# switch back to the previous branch before we switched
git switch -

Command available on version Git 2.23.0 or higher

Command for create zip archive without gem's 📁

Andrey — Wed, 03 Jul 2019 12:39:38 +0000

class CreateZipCommand
  def call(files)
    # Create temp directory for files 
    tmp_dir = Dir.mktmpdir
    tmp_zip_path = File.join(tmp_dir, "files.zip")

    # Move files to the temporary folder you created above
    files.map do |file|
      download_file(file, tmp_dir)
    end

    # Go to the folder and archive the entire contents
    `cd #{tmp_dir} && zip #{tmp_zip_path} ./*`

    # Return zip path
    tmp_zip_path
  end
end

> CreateZipCommand.new.call(files)
=> "/var/folders/bk/0c864z710654sx555jpdpx9c0000gn/T/d20190126-7447-d27fpl/files.zip")

Most gems for working with archives eat a lot of memory when working with large files. This solution does not have these problems.

Make sure that the zip utility is installed on your computer - it don't work without it