Allow #fetch access in Rash

3 files changed, 54 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1643152..f1f33dd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 * [#183](https://github.com/intridea/hashie/pull/183): Added Mash#load with YAML file support - [@gregory](https://github.com/gregory).
 * [#197](https://github.com/intridea/hashie/pull/197): Dont convert keys to string on initalization of mash - [@gregory](https://github.com/gregory).
 * [#201](https://github.com/intridea/hashie/pull/201): Hashie::Trash transforms can be inherited - [@fobocaster](https://github.com/fobocaster).
+* [#189](https://github.com/intridea/hashie/pull/189): Added Rash#fetch - [@medcat](https://github.com/medcat).
 * Your contribution here.
 
 ## 3.2.0 (7/10/2014)
diff --git a/lib/hashie/rash.rb b/lib/hashie/rash.rb
index abbff8e..1e059f3 100644
--- a/lib/hashie/rash.rb
+++ b/lib/hashie/rash.rb
@@ -61,6 +61,28 @@ module Hashie
     end
 
     #
+    # Raise (or yield) unless something matches the key.
+    #
+    def fetch(*args)
+      fail ArgumentError, "Expected 1-2 arguments, got #{args.length}" \
+        unless (1..2).cover?(args.length)
+
+      key, default = args
+
+      all(key) do |value|
+        return value
+      end
+
+      if block_given?
+        yield key
+      elsif default
+        default
+      else
+        fail KeyError, "key not found: #{key.inspect}"
+      end
+    end
+
+    #
     # Return everything that matches the query.
     #
     def all(query)
@@ -106,6 +128,10 @@ module Hashie
       @hash.send(*args, &block)
     end
 
+    def respond_to_missing?(*args)
+      @hash.respond_to?(*args)
+    end
+
     private
 
     def optimize_if_necessary!
diff --git a/spec/hashie/rash_spec.rb b/spec/hashie/rash_spec.rb
index 20b2652..914e7b4 100644
--- a/spec/hashie/rash_spec.rb
+++ b/spec/hashie/rash_spec.rb
@@ -47,4 +47,31 @@ describe Hashie::Rash do
     expect(subject['abcdef']).to eq 'bcd'
     expect(subject['ffffff']).to be_nil
   end
+
+  it 'finds using the find method' do
+    expect(subject.fetch(10.1)).to eq 'rangey'
+    expect(subject.fetch(true)).to be false
+  end
+
+  it 'raises in find unless a key matches' do
+    expect { subject.fetch(1_000_000) }.to raise_error(KeyError)
+  end
+
+  it 'yields in find unless a key matches' do
+    expect { |y| subject.fetch(1_000_000, &y) }.to yield_control
+    expect { |y| subject.fetch(10.1, &y) }.to_not yield_control
+  end
+
+  it 'gives a default value' do
+    expect(subject.fetch(10.1, 'noop')).to eq 'rangey'
+    expect(subject.fetch(1_000_000, 'noop')).to eq 'noop'
+    expect(subject.fetch(1_000_000) { 'noop' }).to eq 'noop'
+    expect(subject.fetch(1_000_000) { |k| k }).to eq 1_000_000
+    expect(subject.fetch(1_000_000, 'noop') { 'op' }).to eq 'op'
+  end
+
+  it 'responds to hash methods' do
+    expect(subject.respond_to?(:to_a)).to be true
+    expect(subject.methods).to_not include(:to_a)
+  end
 end