Recursion Exercise: Add #contains? exercise

recursion/2_contains/.rspec

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+--require spec_helper --format documentation --color

recursion/2_contains/exercises/contains_exercises.rb

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+def contains?(hash, search_value)
+  # Write a method that recursively searches for a value in a nested hash.
+  # It should return `true` if the object contains that value.
+  #
+  # Examples:
+  # contains?({ foo: { bar: "baz" } }, "baz") # true
+  # contains?({ foo: { bar: "baz" } }, "egg") # false
+end

recursion/2_contains/spec/contains_spec.rb

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+require_relative "../exercises/contains_exercises"
+
+describe "#contains?" do
+  let(:nested_hash) do
+    {
+      data: {
+        duplicate: "e",
+        stuff: {
+          thing: {
+            banana: "banana",
+            more_stuff: {
+              something: "foo"
+            }
+          }
+        },
+        info: {
+          duplicate: "e",
+          magic_number: 44,
+          empty: nil
+        }
+      }
+    }
+  end
+
+  it "returns true if the provided number is a value in the hash" do
+    present_number = 44
+    expect(contains?(nested_hash, present_number)).to be true
+  end
+
+  xit "returns true if the provided string is a value in the hash" do
+    present_string = "foo"
+    expect(contains?(nested_hash, present_string)).to be true
+  end
+
+  xit "returns false when the provided string is not a value in the hash" do
+    absent_string = "bar"
+    expect(contains?(nested_hash, absent_string)).to be false
+  end
+
+  xit "returns true when looking for a value that is present multiple times" do
+    duplicated_value = "e"
+    expect(contains?(nested_hash, duplicated_value)).to be true
+  end
+
+  xit "returns true when the provided value is present and is `nil`" do
+    expect(contains?(nested_hash, nil)).to be true
+  end
+end

recursion/2_contains/spec/spec_helper.rb

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+RSpec.configure do |config|
+  config.expect_with :rspec do |expectations|
+    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
+  end
+
+  config.mock_with :rspec do |mocks|
+    mocks.verify_partial_doubles = true
+  end
+
+  config.shared_context_metadata_behavior = :apply_to_host_groups
+end
+
+module FormatterOverrides
+  def dump_pending(_)
+  end
+end
+
+RSpec::Core::Formatters::DocumentationFormatter.prepend FormatterOverrides

solutions/recursion/2_contains/.rspec

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+--require spec_helper --format documentation --color

solutions/recursion/2_contains/exercises/contains_exercises.rb

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+def contains?(hash, search_value)
+  values = hash.values
+  return true if values.include?(search_value)
+
+  nested_hashes = values.select { |value| value.is_a?(Hash) }
+  nested_hashes.any? { |nested_hash| contains?(nested_hash, search_value) }
+end
+

solutions/recursion/2_contains/spec/contains_spec.rb

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+require_relative "../exercises/contains_exercises"
+
+describe "#contains?" do
+  let(:nested_hash) do
+    {
+      data: {
+        duplicate: "e",
+        stuff: {
+          thing: {
+            banana: "banana",
+            more_stuff: {
+              something: "foo"
+            }
+          }
+        },
+        info: {
+          duplicate: "e",
+          magic_number: 44,
+          empty: nil
+        }
+      }
+    }
+  end
+
+  it "returns true if the provided number is a value in the hash" do
+    present_number = 44
+    expect(contains?(nested_hash, present_number)).to be true
+  end
+
+  it "returns true if the provided string is a value in the hash" do
+    present_string = "foo"
+    expect(contains?(nested_hash, present_string)).to be true
+  end
+
+  it "returns false when the provided string is not a value in the hash" do
+    absent_string = "bar"
+    expect(contains?(nested_hash, absent_string)).to be false
+  end
+
+  it "returns true when looking for a value that is present multiple times" do
+    duplicated_value = "e"
+    expect(contains?(nested_hash, duplicated_value)).to be true
+  end
+
+  it "returns true when the provided value is present and is `nil`" do
+    expect(contains?(nested_hash, nil)).to be true
+  end
+end

solutions/recursion/2_contains/spec/spec_helper.rb

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+RSpec.configure do |config|
+  config.expect_with :rspec do |expectations|
+    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
+  end
+
+  config.mock_with :rspec do |mocks|
+    mocks.verify_partial_doubles = true
+  end
+
+  config.shared_context_metadata_behavior = :apply_to_host_groups
+end
+
+module FormatterOverrides
+  def dump_pending(_)
+  end
+end
+
+RSpec::Core::Formatters::DocumentationFormatter.prepend FormatterOverrides