From 94b1defab058c7f58087905d6fb8d025cb2a718d Mon Sep 17 00:00:00 2001
From: Jack Chu <jack@jackchu.com>
Date: Wed, 26 Jul 2017 23:08:00 -0400
Subject: [PATCH 1/6] Add a simple context plugin

---
 .rubocop.yml             |  5 ++-
 CHANGELOG.md             |  2 ++
 README.md                | 49 ++++++++++++++++++++++++++++
 lib/retriable.rb         |  2 +-
 lib/retriable/context.rb | 16 ++++++++++
 spec/context_spec.rb     | 69 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 141 insertions(+), 2 deletions(-)
 create mode 100644 lib/retriable/context.rb
 create mode 100644 spec/context_spec.rb

diff --git a/.rubocop.yml b/.rubocop.yml
index e2858af..06c59a2 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -6,7 +6,7 @@ Style/Documentation:
 
 Style/TrailingCommaInArguments:
   EnforcedStyleForMultiline: comma
-  
+
 Style/TrailingCommaInLiteral:
   EnforcedStyleForMultiline: comma
 
@@ -19,6 +19,9 @@ Style/IndentArray:
 Style/IndentHash:
   Enabled: false
 
+Style/NegatedIf:
+  Enabled: false
+
 Metrics/ClassLength:
   Enabled: false
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 169f779..fee6b28 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## HEAD
 
+* Added contexts feature. Thanks to @apurvis.
+
 ## 3.0.2
 
 * Add configuration and options validation.
diff --git a/README.md b/README.md
index 02256e0..0cc5018 100644
--- a/README.md
+++ b/README.md
@@ -223,6 +223,55 @@ ensure
 end
 ```
 
+## Contexts
+
+There is a separate plugin to enable the context feature. It's not included by default; to use it do:
+
+```ruby
+require 'retriable/contexts'
+```
+
+Contexts allow you to coordinate sets of Retriable options across an application.  Each context is basically an argument hash for `Retriable.retriable` that is stored in the `Retriable` module as a simple `Hash` and is accessible by name. For example:
+
+```ruby
+Retriable.configure do |config, context|
+  context[:aws] = {
+    tries: 3,
+    base_interval: 5,
+    on_retry: Proc.new { puts 'Curse you, AWS!' }
+  }
+  contexts[:mysql] = {
+    tries: 10,
+    multiplier: 2.5,
+    on: Mysql::DeadlockException
+  }
+end
+```
+
+This will create two contexts, `aws` and `mysql`, which allow you to reuse different backoff strategies across your application without continually passing those strategy options to the `retriable` method.
+
+These are used simply by calling `Retriable.with_context`:
+
+```ruby
+# Will retry all exceptions
+Retriable.with_context(:aws) do
+  # aws_call
+end
+
+# Will retry Mysql::DeadlockException
+Retriable.with_context(:mysql) do
+  # write_to_table
+end
+```
+
+You can even temporarily override individual options for a configured context:
+
+```ruby
+Retriable.with_context(:mysql, tries: 30) do
+  # write_to_table
+end
+```
+
 ## Kernel Extension
 
 If you want to call `Retriable.retriable` without the `Retriable` module prefix and you don't mind extending `Kernel`,
diff --git a/lib/retriable.rb b/lib/retriable.rb
index e58bbeb..f465d46 100644
--- a/lib/retriable.rb
+++ b/lib/retriable.rb
@@ -6,7 +6,7 @@
 module Retriable
   module_function
 
-  def self.configure
+  def configure
     yield(config)
   end
 
diff --git a/lib/retriable/context.rb b/lib/retriable/context.rb
new file mode 100644
index 0000000..fa5aa49
--- /dev/null
+++ b/lib/retriable/context.rb
@@ -0,0 +1,16 @@
+module Retriable
+  module_function
+
+  def configure
+    yield(config, context)
+  end
+
+  def context
+    @context ||= {}
+  end
+
+  def with_context(key, options = {}, &block)
+    raise ArgumentError, "Context #{key} is not found." if !context.key?(key)
+    retriable(context[key].merge(options), &block) if block
+  end
+end
diff --git a/spec/context_spec.rb b/spec/context_spec.rb
new file mode 100644
index 0000000..03b3443
--- /dev/null
+++ b/spec/context_spec.rb
@@ -0,0 +1,69 @@
+require_relative "spec_helper"
+
+class TestError < Exception; end
+
+describe "Retriable Context" do
+  subject do
+    Retriable
+  end
+
+  before do
+    require_relative "../lib/retriable/context"
+    srand 0
+  end
+
+  describe "with context and sleep disabled" do
+    before do
+      Retriable.configure do |c, context|
+        c.sleep_disabled = true
+        context[:sql] = { tries: 1 }
+        context[:api] = { tries: 3 }
+      end
+    end
+
+    it "sql context stops at first try if the block does not raise an exception" do
+      tries = 0
+      subject.with_context(:sql) do
+        tries += 1
+      end
+
+      expect(tries).must_equal 1
+    end
+
+    it "with_context respects the context options" do
+      tries = 0
+
+      expect do
+        subject.with_context(:api) do
+          tries += 1
+          raise StandardError.new, "StandardError occurred"
+        end
+      end.must_raise StandardError
+
+      expect(tries).must_equal 3
+    end
+
+    it "with_context allows override options" do
+      tries = 0
+
+      expect do
+        subject.with_context(:sql, tries: 5) do
+          tries += 1
+          raise StandardError.new, "StandardError occurred"
+        end
+      end.must_raise StandardError
+
+      expect(tries).must_equal 5
+    end
+
+    it "raises an ArgumentError when the context isn't found" do
+      tries = 0
+
+      expect do
+        subject.with_context(:wtf) do
+          tries += 1
+        end
+      end.must_raise ArgumentError
+    end
+  end
+end

From 4e35ddc5cf1235637d4321801b44565d9751e378 Mon Sep 17 00:00:00 2001
From: Jack Chu <jack@jackchu.com>
Date: Thu, 27 Jul 2017 02:53:28 -0400
Subject: [PATCH 2/6] Move context feature into core

---
 README.md                        | 26 ++++++------
 lib/retriable.rb                 |  8 ++++
 lib/retriable/config.rb          |  2 +
 lib/retriable/context.rb         | 16 --------
 lib/retriable/core_ext/kernel.rb |  4 ++
 spec/config_spec.rb              |  4 ++
 spec/context_spec.rb             | 69 --------------------------------
 spec/retriable_spec.rb           | 55 +++++++++++++++++++++++++
 8 files changed, 85 insertions(+), 99 deletions(-)
 delete mode 100644 lib/retriable/context.rb
 delete mode 100644 spec/context_spec.rb

diff --git a/README.md b/README.md
index 0cc5018..02b6d14 100644
--- a/README.md
+++ b/README.md
@@ -225,22 +225,16 @@ end
 
 ## Contexts
 
-There is a separate plugin to enable the context feature. It's not included by default; to use it do:
+Contexts allow you to coordinate sets of Retriable options across an application.  Each context is basically an argument hash for `Retriable.retriable` that is stored in the `Retriable.config` as a simple `Hash` and is accessible by name. For example:
 
 ```ruby
-require 'retriable/contexts'
-```
-
-Contexts allow you to coordinate sets of Retriable options across an application.  Each context is basically an argument hash for `Retriable.retriable` that is stored in the `Retriable` module as a simple `Hash` and is accessible by name. For example:
-
-```ruby
-Retriable.configure do |config, context|
-  context[:aws] = {
+Retriable.configure do |c|
+  c.context[:aws] = {
     tries: 3,
     base_interval: 5,
     on_retry: Proc.new { puts 'Curse you, AWS!' }
   }
-  contexts[:mysql] = {
+  c.context[:mysql] = {
     tries: 10,
     multiplier: 2.5,
     on: Mysql::DeadlockException
@@ -250,16 +244,16 @@ end
 
 This will create two contexts, `aws` and `mysql`, which allow you to reuse different backoff strategies across your application without continually passing those strategy options to the `retriable` method.
 
-These are used simply by calling `Retriable.with_context`:
+These are used simply by calling `Retriable.retriable_with_context`:
 
 ```ruby
 # Will retry all exceptions
-Retriable.with_context(:aws) do
+Retriable.retriable_with_context(:aws) do
   # aws_call
 end
 
 # Will retry Mysql::DeadlockException
-Retriable.with_context(:mysql) do
+Retriable.retriable_with_context(:mysql) do
   # write_to_table
 end
 ```
@@ -267,7 +261,7 @@ end
 You can even temporarily override individual options for a configured context:
 
 ```ruby
-Retriable.with_context(:mysql, tries: 30) do
+Retriable.retriable_with_context(:mysql, tries: 30) do
   # write_to_table
 end
 ```
@@ -295,6 +289,10 @@ and then you can call `#retriable` in any context like this:
 retriable do
   # code here...
 end
+
+retriable_with_context(:api) do
+  # code here...
+end
 ```
 
 ## Proxy Wrapper Object
diff --git a/lib/retriable.rb b/lib/retriable.rb
index f465d46..b37f544 100644
--- a/lib/retriable.rb
+++ b/lib/retriable.rb
@@ -14,6 +14,14 @@ def config
     @config ||= Config.new
   end
 
+  def retriable_with_context(context_key, options = {}, &block)
+    if !config.context.key?(context_key)
+      raise ArgumentError, "#{context_key} not found in Retriable.config.context"
+    end
+
+    retriable(config.context[context_key].merge(options), &block) if block
+  end
+
   def retriable(opts = {})
     local_config = opts.empty? ? config : Config.new(config.to_h.merge(opts))
 
diff --git a/lib/retriable/config.rb b/lib/retriable/config.rb
index 531c060..f186b70 100644
--- a/lib/retriable/config.rb
+++ b/lib/retriable/config.rb
@@ -9,6 +9,7 @@ class Config
       :timeout,
       :on,
       :on_retry,
+      :context,
     ].freeze
 
     attr_accessor(*ATTRIBUTES)
@@ -27,6 +28,7 @@ def initialize(opts = {})
       @timeout          = nil
       @on               = [StandardError]
       @on_retry         = nil
+      @context          = {}
 
       opts.each do |k, v|
         raise ArgumentError, "#{k} is not a valid option" if !ATTRIBUTES.include?(k)
diff --git a/lib/retriable/context.rb b/lib/retriable/context.rb
deleted file mode 100644
index fa5aa49..0000000
--- a/lib/retriable/context.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-module Retriable
-  module_function
-
-  def configure
-    yield(config, context)
-  end
-
-  def context
-    @context ||= {}
-  end
-
-  def with_context(key, options = {}, &block)
-    raise ArgumentError, "Context #{key} is not found." if !context.key?(key)
-    retriable(context[key].merge(options), &block) if block
-  end
-end
diff --git a/lib/retriable/core_ext/kernel.rb b/lib/retriable/core_ext/kernel.rb
index d43073a..18291ba 100644
--- a/lib/retriable/core_ext/kernel.rb
+++ b/lib/retriable/core_ext/kernel.rb
@@ -4,4 +4,8 @@ module Kernel
   def retriable(opts = {}, &block)
     Retriable.retriable(opts, &block)
   end
+
+  def retriable_with_context(context_key, opts = {}, &block)
+    Retriable.retriable_with_context(context_key, opts, &block)
+  end
 end
diff --git a/spec/config_spec.rb b/spec/config_spec.rb
index 181a0fd..9a9b2e1 100644
--- a/spec/config_spec.rb
+++ b/spec/config_spec.rb
@@ -45,6 +45,10 @@
     expect(subject.new.on_retry).must_be_nil
   end
 
+  it "context defaults to {}" do
+    expect(subject.new.context).must_equal Hash.new
+  end
+
   it "raises errors on invalid configuration" do
     assert_raises ArgumentError do
       subject.new(does_not_exist: 123)
diff --git a/spec/context_spec.rb b/spec/context_spec.rb
deleted file mode 100644
index 03b3443..0000000
--- a/spec/context_spec.rb
+++ /dev/null
@@ -1,69 +0,0 @@
-require_relative "spec_helper"
-
-class TestError < Exception; end
-
-describe "Retriable Context" do
-  subject do
-    Retriable
-  end
-
-  before do
-    require_relative "../lib/retriable/context"
-    srand 0
-  end
-
-  describe "with context and sleep disabled" do
-    before do
-      Retriable.configure do |c, context|
-        c.sleep_disabled = true
-        context[:sql] = { tries: 1 }
-        context[:api] = { tries: 3 }
-      end
-    end
-
-    it "sql context stops at first try if the block does not raise an exception" do
-      tries = 0
-      subject.with_context(:sql) do
-        tries += 1
-      end
-
-      expect(tries).must_equal 1
-    end
-
-    it "with_context respects the context options" do
-      tries = 0
-
-      expect do
-        subject.with_context(:api) do
-          tries += 1
-          raise StandardError.new, "StandardError occurred"
-        end
-      end.must_raise StandardError
-
-      expect(tries).must_equal 3
-    end
-
-    it "with_context allows override options" do
-      tries = 0
-
-      expect do
-        subject.with_context(:sql, tries: 5) do
-          tries += 1
-          raise StandardError.new, "StandardError occurred"
-        end
-      end.must_raise StandardError
-
-      expect(tries).must_equal 5
-    end
-
-    it "raises an ArgumentError when the context isn't found" do
-      tries = 0
-
-      expect do
-        subject.with_context(:wtf) do
-          tries += 1
-        end
-      end.must_raise ArgumentError
-    end
-  end
-end
diff --git a/spec/retriable_spec.rb b/spec/retriable_spec.rb
index 5abc04a..261fab4 100644
--- a/spec/retriable_spec.rb
+++ b/spec/retriable_spec.rb
@@ -376,4 +376,59 @@ class SecondTestError < TestError; end
       Retriable.retriable(does_not_exist: 123)
     end
   end
+
+  describe "#retriable_with_context" do
+    before do
+      Retriable.configure do |c|
+        c.sleep_disabled = true
+        c.context[:sql] = { tries: 1 }
+        c.context[:api] = { tries: 3 }
+      end
+    end
+
+    it "sql context stops at first try if the block does not raise an exception" do
+      tries = 0
+      subject.retriable_with_context(:sql) do
+        tries += 1
+      end
+
+      expect(tries).must_equal 1
+    end
+
+    it "retriable_with_context respects the context options" do
+      tries = 0
+
+      expect do
+        subject.retriable_with_context(:api) do
+          tries += 1
+          raise StandardError.new, "StandardError occurred"
+        end
+      end.must_raise StandardError
+
+      expect(tries).must_equal 3
+    end
+
+    it "retriable_with_context allows override options" do
+      tries = 0
+
+      expect do
+        subject.retriable_with_context(:sql, tries: 5) do
+          tries += 1
+          raise StandardError.new, "StandardError occurred"
+        end
+      end.must_raise StandardError
+
+      expect(tries).must_equal 5
+    end
+
+    it "raises an ArgumentError when the context isn't found" do
+      tries = 0
+
+      expect do
+        subject.retriable_with_context(:wtf) do
+          tries += 1
+        end
+      end.must_raise ArgumentError
+    end
+  end
 end

From 43da6cd6ac178adcc18e00851330a2cc98121401 Mon Sep 17 00:00:00 2001
From: Jack Chu <jack@jackchu.com>
Date: Fri, 28 Jul 2017 01:02:47 -0400
Subject: [PATCH 3/6] Pluralize config.context to config.contexts

---
 README.md               | 4 ++--
 lib/retriable.rb        | 6 +++---
 lib/retriable/config.rb | 4 ++--
 spec/config_spec.rb     | 4 ++--
 spec/retriable_spec.rb  | 4 ++--
 5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index 02b6d14..31d1534 100644
--- a/README.md
+++ b/README.md
@@ -229,12 +229,12 @@ Contexts allow you to coordinate sets of Retriable options across an application
 
 ```ruby
 Retriable.configure do |c|
-  c.context[:aws] = {
+  c.contexts[:aws] = {
     tries: 3,
     base_interval: 5,
     on_retry: Proc.new { puts 'Curse you, AWS!' }
   }
-  c.context[:mysql] = {
+  c.contexts[:mysql] = {
     tries: 10,
     multiplier: 2.5,
     on: Mysql::DeadlockException
diff --git a/lib/retriable.rb b/lib/retriable.rb
index b37f544..c10b751 100644
--- a/lib/retriable.rb
+++ b/lib/retriable.rb
@@ -15,11 +15,11 @@ def config
   end
 
   def retriable_with_context(context_key, options = {}, &block)
-    if !config.context.key?(context_key)
-      raise ArgumentError, "#{context_key} not found in Retriable.config.context"
+    if !config.contexts.key?(context_key)
+      raise ArgumentError, "#{context_key} not found in Retriable.config.contexts"
     end
 
-    retriable(config.context[context_key].merge(options), &block) if block
+    retriable(config.contexts[context_key].merge(options), &block) if block
   end
 
   def retriable(opts = {})
diff --git a/lib/retriable/config.rb b/lib/retriable/config.rb
index f186b70..624b9a2 100644
--- a/lib/retriable/config.rb
+++ b/lib/retriable/config.rb
@@ -9,7 +9,7 @@ class Config
       :timeout,
       :on,
       :on_retry,
-      :context,
+      :contexts,
     ].freeze
 
     attr_accessor(*ATTRIBUTES)
@@ -28,7 +28,7 @@ def initialize(opts = {})
       @timeout          = nil
       @on               = [StandardError]
       @on_retry         = nil
-      @context          = {}
+      @contexts          = {}
 
       opts.each do |k, v|
         raise ArgumentError, "#{k} is not a valid option" if !ATTRIBUTES.include?(k)
diff --git a/spec/config_spec.rb b/spec/config_spec.rb
index 9a9b2e1..ddc499d 100644
--- a/spec/config_spec.rb
+++ b/spec/config_spec.rb
@@ -45,8 +45,8 @@
     expect(subject.new.on_retry).must_be_nil
   end
 
-  it "context defaults to {}" do
-    expect(subject.new.context).must_equal Hash.new
+  it "contexts defaults to {}" do
+    expect(subject.new.contexts).must_equal Hash.new
   end
 
   it "raises errors on invalid configuration" do
diff --git a/spec/retriable_spec.rb b/spec/retriable_spec.rb
index 261fab4..ac27ea8 100644
--- a/spec/retriable_spec.rb
+++ b/spec/retriable_spec.rb
@@ -381,8 +381,8 @@ class SecondTestError < TestError; end
     before do
       Retriable.configure do |c|
         c.sleep_disabled = true
-        c.context[:sql] = { tries: 1 }
-        c.context[:api] = { tries: 3 }
+        c.contexts[:sql] = { tries: 1 }
+        c.contexts[:api] = { tries: 3 }
       end
     end
 

From ea5b10f7e8e0b9be8e4f9fa9130b48e3aa7a4d48 Mon Sep 17 00:00:00 2001
From: Jack Chu <jack@jackchu.com>
Date: Fri, 28 Jul 2017 01:06:23 -0400
Subject: [PATCH 4/6] Rename retriable_with_context to with_context, unless
 it's in the kernel extension to keep it descriptive

---
 README.md                        |  8 ++++----
 lib/retriable.rb                 |  2 +-
 lib/retriable/core_ext/kernel.rb |  2 +-
 spec/retriable_spec.rb           | 14 +++++++-------
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 31d1534..6ac8b29 100644
--- a/README.md
+++ b/README.md
@@ -244,16 +244,16 @@ end
 
 This will create two contexts, `aws` and `mysql`, which allow you to reuse different backoff strategies across your application without continually passing those strategy options to the `retriable` method.
 
-These are used simply by calling `Retriable.retriable_with_context`:
+These are used simply by calling `Retriable.with_context`:
 
 ```ruby
 # Will retry all exceptions
-Retriable.retriable_with_context(:aws) do
+Retriable.with_context(:aws) do
   # aws_call
 end
 
 # Will retry Mysql::DeadlockException
-Retriable.retriable_with_context(:mysql) do
+Retriable.with_context(:mysql) do
   # write_to_table
 end
 ```
@@ -261,7 +261,7 @@ end
 You can even temporarily override individual options for a configured context:
 
 ```ruby
-Retriable.retriable_with_context(:mysql, tries: 30) do
+Retriable.with_context(:mysql, tries: 30) do
   # write_to_table
 end
 ```
diff --git a/lib/retriable.rb b/lib/retriable.rb
index c10b751..48ed279 100644
--- a/lib/retriable.rb
+++ b/lib/retriable.rb
@@ -14,7 +14,7 @@ def config
     @config ||= Config.new
   end
 
-  def retriable_with_context(context_key, options = {}, &block)
+  def with_context(context_key, options = {}, &block)
     if !config.contexts.key?(context_key)
       raise ArgumentError, "#{context_key} not found in Retriable.config.contexts"
     end
diff --git a/lib/retriable/core_ext/kernel.rb b/lib/retriable/core_ext/kernel.rb
index 18291ba..a95c9f2 100644
--- a/lib/retriable/core_ext/kernel.rb
+++ b/lib/retriable/core_ext/kernel.rb
@@ -6,6 +6,6 @@ def retriable(opts = {}, &block)
   end
 
   def retriable_with_context(context_key, opts = {}, &block)
-    Retriable.retriable_with_context(context_key, opts, &block)
+    Retriable.with_context(context_key, opts, &block)
   end
 end
diff --git a/spec/retriable_spec.rb b/spec/retriable_spec.rb
index ac27ea8..49bd2b8 100644
--- a/spec/retriable_spec.rb
+++ b/spec/retriable_spec.rb
@@ -377,7 +377,7 @@ class SecondTestError < TestError; end
     end
   end
 
-  describe "#retriable_with_context" do
+  describe "#with_context" do
     before do
       Retriable.configure do |c|
         c.sleep_disabled = true
@@ -388,18 +388,18 @@ class SecondTestError < TestError; end
 
     it "sql context stops at first try if the block does not raise an exception" do
       tries = 0
-      subject.retriable_with_context(:sql) do
+      subject.with_context(:sql) do
         tries += 1
       end
 
       expect(tries).must_equal 1
     end
 
-    it "retriable_with_context respects the context options" do
+    it "with_context respects the context options" do
       tries = 0
 
       expect do
-        subject.retriable_with_context(:api) do
+        subject.with_context(:api) do
           tries += 1
           raise StandardError.new, "StandardError occurred"
         end
@@ -408,11 +408,11 @@ class SecondTestError < TestError; end
       expect(tries).must_equal 3
     end
 
-    it "retriable_with_context allows override options" do
+    it "with_context allows override options" do
       tries = 0
 
       expect do
-        subject.retriable_with_context(:sql, tries: 5) do
+        subject.with_context(:sql, tries: 5) do
           tries += 1
           raise StandardError.new, "StandardError occurred"
         end
@@ -425,7 +425,7 @@ class SecondTestError < TestError; end
       tries = 0
 
       expect do
-        subject.retriable_with_context(:wtf) do
+        subject.with_context(:wtf) do
           tries += 1
         end
       end.must_raise ArgumentError

From aeb16a7bb420c8a18595dba64cffa0d5af00127b Mon Sep 17 00:00:00 2001
From: Jack Chu <jack@jackchu.com>
Date: Fri, 28 Jul 2017 01:15:16 -0400
Subject: [PATCH 5/6] Remove unnecessary trailing comma in arg list

---
 lib/retriable.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/retriable.rb b/lib/retriable.rb
index 48ed279..04644ec 100644
--- a/lib/retriable.rb
+++ b/lib/retriable.rb
@@ -48,7 +48,7 @@ def retriable(opts = {})
         base_interval:  base_interval,
         multiplier:     multiplier,
         max_interval:   max_interval,
-        rand_factor:    rand_factor,
+        rand_factor:    rand_factor
       ).intervals
     end
 

From de3fcb8c8c70f213edacf07d481e010e9eb4ff70 Mon Sep 17 00:00:00 2001
From: Jack Chu <jack@jackchu.com>
Date: Fri, 28 Jul 2017 01:34:08 -0400
Subject: [PATCH 6/6] Add available contexts in the exception message when
 calling a context key that doesn't exist

---
 lib/retriable.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/retriable.rb b/lib/retriable.rb
index 04644ec..01fffe6 100644
--- a/lib/retriable.rb
+++ b/lib/retriable.rb
@@ -16,7 +16,7 @@ def config
 
   def with_context(context_key, options = {}, &block)
     if !config.contexts.key?(context_key)
-      raise ArgumentError, "#{context_key} not found in Retriable.config.contexts"
+      raise ArgumentError, "#{context_key} not found in Retriable.config.contexts. Here the available contexts: #{config.contexts.keys}"
     end
 
     retriable(config.contexts[context_key].merge(options), &block) if block