Singularize the Filters module

Since we are using single objects from this namespaces, it is much
more suitable to be named in singular than in plural.

lib/rackstash/adapter/logger.rb

@@ -22,7 +22,7 @@ module Rackstash
     # standard library. All logs emitted to the given logger will be emitted
     # with the defined severity (`INFO` by default). Since a log event in
     # Rackstash can contain multiple concatenanted messages, you should make
-    # sure to format them properly with {Filters} or a custom encoder if
+    # sure to format them properly with a {Filter} or a custom encoder if
     # required.
     #
     # While most loggers expect Strings as arguments to their `add` method, some

lib/rackstash/buffer.rb

@@ -337,17 +337,16 @@ module Rackstash
     #
     # Note that the resulting hash still contains an Array of {Message}s in the
     # `"message"` field and a `Time` object in the '@timestamp' field. This
-    # allows the {Flow}'s components (usually the {Filters} or the
-    # {Flow#encoder}) to reject or adapt some messages based on
-    # their original attributes, e.g., their severity or timestamp. It is the
-    # responsibility of the {Flow#encoder} to correctly format the
-    # `"@timestamp"` field.
+    # allows the {Flow}'s components (usually a {Filter} or the {Flow#encoder})
+    # to reject or adapt some messages based on their original attributes, e.g.,
+    # their severity or timestamp. It is the responsibility of the
+    # {Flow#encoder} to correctly format the `"@timestamp"` field.
     #
     # All other fields in the event Hash besides `"message"` and `@timestamp"`
     # are either `Hash`, `Array`, frozen `String`, `Integer` or `Float` objects.
     # All hashes (including nested hashes) use `String` keys.
     #
-    # @return [Hash] the event expected by the event {Filters}.
+    # @return [Hash] the event expected by the event {Filter}s.
     def to_event
       event = fields.to_h
       event[FIELD_TAGS] = tags.to_a

lib/rackstash/filter.rb

@@ -5,13 +5,13 @@
 # This software may be modified and distributed under the terms
 # of the MIT license. See the LICENSE.txt file for details.
 
-require 'rackstash/filters/clear_color'
-require 'rackstash/filters/default_fields'
-require 'rackstash/filters/default_tags'
-require 'rackstash/filters/rename'
-require 'rackstash/filters/replace'
-require 'rackstash/filters/skip_event'
-require 'rackstash/filters/truncate_message'
+require 'rackstash/filter/clear_color'
+require 'rackstash/filter/default_fields'
+require 'rackstash/filter/default_tags'
+require 'rackstash/filter/rename'
+require 'rackstash/filter/replace'
+require 'rackstash/filter/skip_event'
+require 'rackstash/filter/truncate_message'
 
 module Rackstash
   # Filters are part of a {Flow} where they can alter the log event before it is
@@ -28,16 +28,16 @@ module Rackstash
   #
   # A filter can be any object responding to `call`, e.g. a Proc or a concrete
   # class inside this module.
-  module Filters
+  module Filter
     # Create a new filter instance from the specified class and the given
     # arguments. The class can be given as an actual class or as the name of a
     # filter in which case we are resolving it to a class defined inside the
-    # {Rackstash::Filters} namespace.
+    # {Rackstash::Filter} namespace.
     #
     # @param klass [Class, Symbol, String, #call] a description of the class
     #   from which we are creating a new filter object. When giving a `Class`,
     #   we are using it as is. When giving a `String` or `Symbol`, we are
-    #   determining the associated class from the {Rackstash::Filters} module
+    #   determining the associated class from the {Rackstash::Filter} module
     #   and create an instance of that. When giving an object which responds to
     #   `call` already, we return it unchanged, ignoring any additional passed
     #   `args`.
@@ -66,7 +66,7 @@ module Rackstash
     end
 
     # @return [Hash<Symbol => Class>] a Hash with names of filters and their
-    #   respective classes which can be used with {Filters.build} to create a
+    #   respective classes which can be used with {Filter.build} to create a
     #   new filter object
     def self.known
       constants.each_with_object({}) do |const, known|

lib/rackstash/filter/clear_color.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # Remove all ANSI color codes from the `"message"` field of the given event
     # `Hash`.
     #

lib/rackstash/filter/default_fields.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # The {DefaultFields} filter allows to define fields which should be added
     # to an event if they aren't already explicitly set.
     #

lib/rackstash/filter/default_tags.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # The {DefaultTags} filter allows to define tags which should be added
     # to an event if they aren't already explicitly set there. All existing tags
     # on the event are retained.

lib/rackstash/filter/rename.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # Rename one or more fields in the given event.
     #
     # @example

lib/rackstash/filter/replace.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # Replace fields in the given event with new values. A new value can be
     # specified as either a fixed value or as a `Proc` (or any other object
     # responding to `call`). In the latter case, the callable object will be

lib/rackstash/filter/skip_event.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # Skip the further processing of the event of the condition is `true`.
     #
     # This filter is a basic example of how you can write filters which abort

lib/rackstash/filter/truncate_message.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # The Truncate filter can be used to restrict the size of the emitted
     # message. By selectively deleting parts until the message size fits into
     # the defined limit, you can ensure that log events are properly handled by

lib/rackstash/filter/update.rb

@@ -6,7 +6,7 @@
 # of the MIT license. See the LICENSE.txt file for details.
 
 module Rackstash
-  module Filters
+  module Filter
     # Update fields in the given event with new values. A new value can be
     # specified as either a fixed value or as a `Proc` (or any other object
     # responding to `call`). In the latter case, the callable object will be

lib/rackstash/filter_chain.rb

@@ -11,10 +11,10 @@ module Rackstash
   # The FilterChain contains a list of event filters which are used by a {Flow}
   # to mutate an event before it is envoded and sent to the adapter for writing.
   #
-  # A filter is any object responding to `call`, e.g. one of the {Filters} or a
-  # `Proc` object. When running the filters, we call each filter iin turn,
-  # passing the event. The filter can change the event in any way desired but
-  # should make sure that it preserves the basic structure of the event:
+  # A filter is any object responding to `call`, e.g. a {Filter} or a `Proc`
+  # object. When running the filters, we call each filter in turn, passing the
+  # event. The filter can change the event in any way desired but should make
+  # sure that it preserves the basic structure of the event:
   #
   # * Only use basic objects: `Hash`, `Array`, `String`, `Integer`, `Float`.
   # * Hash keys should always be strings
@@ -78,8 +78,8 @@ module Rackstash
     end
 
     # Adds a new filter at the end of the filter chain. You can either give a
-    # callable object (e.g. a `Proc` or one of the {Filters}) or specify the
-    # filter with a given block.
+    # callable object (e.g. a `Proc` or a {Filter}) or specify the filter with
+    # a given block.
     #
     # @param filter_spec (see #build_filter)
     # @raise [TypeError] if no suitable filter could be created from
@@ -236,8 +236,8 @@ module Rackstash
     alias size length
 
     # Prepends a new filter at the beginning of the filter chain. You can either
-    # give a callable object (e.g. a `Proc` or one of the {Filters}) or specify
-    # the filter with a given block.
+    # give a callable object (e.g. a `Proc` or a {Filter}) or specify the filter
+    # with a given block.
     #
     # @param filter_spec (see #build_filter)
     # @raise [TypeError] if we could not build a filter from the given
@@ -296,16 +296,16 @@ module Rackstash
     #   `#call`), we will directly return it. If you give a `Class` plus any
     #   optional initializer arguments, we will return a new instance of that
     #   class. When giving a `String` or `Symbol`, we will resolve it to a
-    #   filter class from the {Rackstash::Filters} module and create a new
+    #   filter class from the {Rackstash::Filter} module and create a new
     #   instance of that class with the additional arguments given to
     #   `initialize`.
     # @return [#call] a filter instance
     def build_filter(filter_spec, &block)
       if filter_spec.empty?
-        return Rackstash::Filters.build(block) if block_given?
+        return Rackstash::Filter.build(block) if block_given?
         raise ArgumentError, 'Need to specify a filter'
       else
-        Rackstash::Filters.build(*filter_spec, &block)
+        Rackstash::Filter.build(*filter_spec, &block)
       end
     end
   end

lib/rackstash/flow.rb

@@ -7,7 +7,7 @@
 
 require 'rackstash/adapter'
 require 'rackstash/encoder'
-require 'rackstash/filters'
+require 'rackstash/filter'
 require 'rackstash/filter_chain'
 
 module Rackstash
@@ -19,7 +19,7 @@ module Rackstash
   # In order to transform and persist log events, a Flow uses several
   # components:
   #
-  # * Any number of {Filters} (zero or more). The filters can change the log
+  # * Any number of {Filter}s (zero or more). The filters can change the log
   #   event before it is passed to the adapter by adding, changing, or removing
   #   fields. The filters also have access to the array of {Message} objects in
   #   `event["messages"]` which provide the original severity and timestamp of
@@ -41,7 +41,7 @@ module Rackstash
   #       encoder Rackstash::Encoder::JSON.new
   #
   #       # Anonymize IPs in the remote_ip field.
-  #       filter Rackstash::Filters::AnonymizeIPMask.new('remote_ip')
+  #       filter Rackstash::Filter::AnonymizeIPMask.new('remote_ip')
   #
   #       # Add the maximum severity of any message in the event into the
   #       # severity and severity_label fields.
@@ -70,9 +70,8 @@ module Rackstash
     #   can be wrapped in an adapter. See {Adapter.[]}
     # @param encoder [#encode] an encoder, usually one of the {Encoder}s. If
     #   this is not given, the adapter's default_encoder will be used.
-    # @param filters [Array<#call>] an array of filters. Can be one of the
-    #   pre-defined {Filters}, a `Proc`, or any other object which responds to
-    #   `call`.
+    # @param filters [Array<#call>] an array of filters. Can be a pre-defined
+    #   {Filter}, a `Proc`, or any other object which responds to `call`.
     # @yieldparam flow [self] if the given block accepts an argument, we yield
     #   `self` as a parameter, else, the block is directly executed in the
     #   context of `self`.

lib/rackstash/message.rb

@@ -14,7 +14,7 @@ module Rackstash
   #
   # In the end, only the `message` field will be included in the final log
   # event. However, the stored meta-data can be useful when filtering or
-  # changing the messages of a log event using {Filters} later.
+  # changing the messages of a log event using a {Filter} later.
   #
   # All `Message` objects and their respective data are immutable after
   # initialization.

spec/rackstash/filter/clear_color_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/clear_color'
+require 'rackstash/filter/clear_color'
 
-describe Rackstash::Filters::ClearColor do
+describe Rackstash::Filter::ClearColor do
   let(:filter) { described_class.new }
 
   it 'removes any ANSI color codes from the message' do

spec/rackstash/filter/default_fields_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/default_fields'
+require 'rackstash/filter/default_fields'
 
-describe Rackstash::Filters::DefaultFields do
+describe Rackstash::Filter::DefaultFields do
   let(:event) {
     {
       'foo' => 'v1',

spec/rackstash/filter/default_tags_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/default_tags'
+require 'rackstash/filter/default_tags'
 
-describe Rackstash::Filters::DefaultTags do
+describe Rackstash::Filter::DefaultTags do
   let(:event) {
     {
       'key' => 'value'

spec/rackstash/filter/rename_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/rename'
+require 'rackstash/filter/rename'
 
-describe Rackstash::Filters::Rename do
+describe Rackstash::Filter::Rename do
   let(:event) {
     {
       'foo' => 'foo value',

spec/rackstash/filter/replace_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/replace'
+require 'rackstash/filter/replace'
 
-describe Rackstash::Filters::Replace do
+describe Rackstash::Filter::Replace do
   let(:event) {
     {
       'foo' => 'foo value',

spec/rackstash/filter/skip_event_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/skip_event'
+require 'rackstash/filter/skip_event'
 
-describe Rackstash::Filters::SkipEvent do
+describe Rackstash::Filter::SkipEvent do
   describe '#initialize' do
     it 'expects a condition' do
       expect { described_class.new }.to raise_error TypeError

spec/rackstash/filter/truncate_message_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/truncate_message'
+require 'rackstash/filter/truncate_message'
 
-describe Rackstash::Filters::TruncateMessage do
+describe Rackstash::Filter::TruncateMessage do
   let(:max_size) { 36 }
   let(:args) { { selectors: [], cut: :bottom } }
   let(:filter) { described_class.new(max_size, **args) }

spec/rackstash/filter/update_spec.rb

@@ -7,9 +7,9 @@
 
 require 'spec_helper'
 
-require 'rackstash/filters/update'
+require 'rackstash/filter/update'
 
-describe Rackstash::Filters::Update do
+describe Rackstash::Filter::Update do
   let(:event) {
     {
       'foo' => 'foo value',

spec/rackstash/filter_spec.rb

@@ -8,9 +8,9 @@
 require 'spec_helper'
 require 'securerandom'
 
-require 'rackstash/filters'
+require 'rackstash/filter'
 
-describe Rackstash::Filters do
+describe Rackstash::Filter do
   let(:filter_class) { Class.new }
   let(:random) { SecureRandom.hex(6) }
   let(:filter_class_name) { :"FilterClass#{random}" }
@@ -60,7 +60,7 @@ describe Rackstash::Filters do
   end
 
   describe '.known' do
-    it 'returns a Hash with known Filters' do
+    it 'returns a Hash with known filters' do
       expect(described_class.known).not_to be_empty
 
       expect(described_class.known.keys).to all(