Merge pull request #1 from salsify/feature/import-from-salsify-kafka

Import tree_reject from salsify_kafka

.gitignore

@@ -7,3 +7,4 @@
 /pkg/
 /spec/reports/
 /tmp/
+*.iml

CHANGELOG.md

@@ -4,8 +4,5 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
-## Unreleased
-
-## 0.1.0 - 2019-03-28
-### Added
+## 1.0.0 - 2019-03-28
 - Initial version

README.md

@@ -1,11 +1,46 @@
-# TreeReject
+# tree_reject
 
-Welcome to your new gem! In this directory, you'll find the files you need to be
-able to package up your Ruby library into a gem. Put your Ruby code in the file
-`lib/tree_reject`. To experiment with that code, run 
-`bin/console` for an interactive prompt.
+[![Build Status](https://travis-ci.org/salsify/tree_reject.svg?branch=master)](https://travis-ci.org/salsify/tree_reject)
 
-TODO: Delete this and the text above, and describe your gem
+[![Gem Version](https://badge.fury.io/rb/tree_reject.svg)](https://badge.fury.io/rb/tree_reject)
+
+`tree_reject` is a Ruby gem that removes deeply nested keys from Ruby Hashes or hash-like objects.
+
+For example:
+
+```ruby
+hash = {
+  a: {
+    aa: {
+      aaa: 'aaa',
+      aab: 'aab'
+    }
+  },
+  b: {
+    ba: 'ba'
+  }
+}
+
+hash.tree_reject({
+  a: {
+    aa: :aaa
+  }
+})
+```
+
+results in:
+```ruby
+{
+  a: {
+    aa: {
+      aab: 'aab'
+    }
+  }, 
+  b: {
+    ba: 'ba'
+  }
+} 
+```
 
 ## Installation
 
@@ -25,7 +60,17 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+`tree_reject` extends Ruby's built-in `Hash`:
+
+```ruby
+my_hash.tree_reject(ignored_keys)
+```
+
+It is also available for objects that support `to_h`.
+
+```ruby
+TreeReject.tree_reject(my_hash_like, ignored_keys)
+```
 
 ## Development
 
@@ -48,4 +93,3 @@ https://github.com/salsify/tree_reject.## License
 
 The gem is available as open source under the terms of the
 [MIT License](http://opensource.org/licenses/MIT).
-

lib/tree_reject.rb

@@ -2,6 +2,57 @@
 
 require 'tree_reject/version'
 
-# Top-level gem module
 module TreeReject
+  extend self
+
+  module TreeRejectHash
+    def tree_reject(ignorned_keys)
+      TreeReject.tree_reject(self, ignorned_keys)
+    end
+  end
+
+  # returns a new map with the ignored keys removed
+  # ignored_keys must be an array of IKItems
+  # IKItem is the type <Symbol | Array<IkItem> | Hash<Symbol, IKItem>>
+  # keys are only removed if their path in the trees match
+  def tree_reject(map, ignored_keys)
+    ignored_leaves = extract_leaves(ignored_keys)
+    ignored_subtrees = extract_subtrees(ignored_keys, ignored_leaves)
+
+    map.to_h.each_with_object({}) do |(k, v), cleaned|
+      if ignored_leaves.include?(k)
+        next
+      elsif v.is_a?(Hash) || v.respond_to?(:attributes)
+        cleaned_v = tree_reject(v.to_h, ignored_subtrees[k])
+        cleaned[k] = cleaned_v unless cleaned_v == {}
+      elsif !v.nil?
+        cleaned[k] = v
+      end
+    end
+  end
+
+  private
+
+  # extract the top level leaves from the ignored_keys tree structure
+  def extract_leaves(ignored_keys)
+    [ignored_keys].flatten.reject { |ignored_key| ignored_key.is_a?(Hash) }
+  end
+
+  # extract the top level subtrees from the ignored_keys tree structure, skipping ones included ignored_leaves
+  def extract_subtrees(ignored_keys, ignored_leaves)
+    [ignored_keys].flatten.select { |ignored_key| ignored_key.is_a?(Hash) }.inject({}) do |h, ignored_subtree|
+      ignored_subtree.each_pair do |k, v|
+        next if ignored_leaves.include?(k)
+
+        if h.key?(k)
+          h[k] << v
+        else
+          h[k] = [v]
+        end
+      end
+      h
+    end
+  end
 end
+
+Hash.send(:include, TreeReject::TreeRejectHash)

lib/tree_reject/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module TreeReject
-  VERSION = '0.1.0'
+  VERSION = '1.0.0'
 end

spec/tree_reject_spec.rb

@@ -4,4 +4,108 @@
   it "has a version number" do
     expect(TreeReject::VERSION).not_to be nil
   end
+
+  context "TreeReject.tree_reject" do
+
+    shared_examples "ignored keys in hash were removed" do
+      specify "hash as object" do
+        actual = TreeReject.tree_reject(original, ignored)
+        expect(actual).to eq expected
+      end
+
+      specify "hash extension" do
+        actual = original.tree_reject(ignored)
+        expect(actual).to eq expected
+      end
+    end
+
+    shared_examples "ignored keys in Virtus-like models were removed" do
+      specify do
+        actual = TreeReject.tree_reject(TestModel.new(original), ignored)
+        expect(actual).to eq expected
+      end
+    end
+
+    class TestModel < Struct.new(:a, :h, :v)
+      def initialize(**attributes)
+        attributes.each do |key, value|
+          send("#{key}=", value)
+        end
+      end
+
+      alias_method :to_hash, :to_h
+    end
+
+    context "removes top level key" do
+      let(:original) { { a: 1 } }
+      let(:expected) { {} }
+      let(:ignored) { :a }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+    context "removed top level key with children" do
+      let(:original) { { h: { b: 1 } } }
+      let(:expected) { {} }
+      let(:ignored) { :h }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+    context "removed child key" do
+      let(:original) { { h: { b: 1, c: 2 } } }
+      let(:expected) { { h: { c: 2 } } }
+      let(:ignored) { { h: :b } }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+    context "non-existent top-level key ignored" do
+      let(:original) { { a: 1 } }
+      let(:expected) { { a: 1 } }
+      let(:ignored) { :b }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+    context "non-existent child key ignored" do
+      let(:original) { { a: 1 } }
+      let(:expected) { { a: 1 } }
+      let(:ignored) { { b: :c } }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+    context "sibling keys removed, array of hashes" do
+      let(:original) { { h: { b: 1, c: 2, d: 3 } } }
+      let(:expected) { { h: { d: 3 } } }
+      let(:ignored) { [{ h: :b }, { h: :c }] }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+    context "sibling keys removed, hash of arrays" do
+      let(:original) { { h: { b: 1, c: 2, d: 3 } } }
+      let(:expected) { { h: { d: 3 } } }
+      let(:ignored) { { h: [:b, :c] } }
+
+      it_behaves_like "ignored keys in hash were removed"
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+
+
+    context "removed Virtus object child key" do
+      let(:original) { { v: { a: 1 } } }
+      let(:expected) { {} }
+      let(:ignored) { { v: :a } }
+
+      it_behaves_like "ignored keys in Virtus-like models were removed"
+    end
+  end
 end