Add a way to elide diffs

CHANGELOG.md

@@ -1,5 +1,55 @@
 # Changelog
 
+## Unreleased
+
+### Breaking changes
+
+* Diff formatters are now gone in favor of operation tree flatteners. If you
+  have a custom diff formatter, you will want to inherit from
+  SuperDiff::OperationTreeFlatteners::Base (or an appropriate subclass).
+  Additionally, the `add_extra_diff_formatter_class` configuration option has
+  disappeared; instead, operation tree classes are expected to have an
+  `operation_tree_flattener_class` method, which should return your custom
+  operation tree flattener class.
+
+### Features
+
+* Add the ability to compress long diffs by eliding sections of unchanged data
+  (data which is present in both "expected" and "actual" values). This
+  functionality is not enabled by default; rather, you will need to activate it.
+  At a minimum, you will want to add this to your test helper:
+
+  ``` ruby
+  SuperDiff.configure do |config|
+    config.diff_elision_enabled = true
+  end
+  ```
+
+  By default the elision will be pretty aggressive, but if you want to preserve
+  more of the unchanged lines in the diff, you can set `diff_elision_maximum`:
+
+  ``` ruby
+  SuperDiff.configure do |config|
+    config.diff_elision_enabled = true
+    config.diff_elision_maximum = 10
+  end
+  ```
+
+  Here, the gem will try to keep at least 10 unchanged lines in between changed
+  lines.
+
+### Features
+
+* Update inspection of Doubles to include stubbed methods and their values.
+
+### Improvements
+
+* Change how objects are inspected on a single line so that instance variables
+  are always sorted.
+* Make a tweak to how hashes are presented in diffs and inspections: a hash that
+  has a mixture of symbols and strings will be presented as though all keys are
+  strings (i.e. hashrocket syntax).
+
 ## 0.7.0 - 2021-05-07
 
 ### Features

README.md

@@ -202,7 +202,6 @@ SuperDiff.configure do |config|
   config.add_extra_differ_class(YourDiffer)
   config.add_extra_operation_tree_builder_class(YourOperationTreeBuilder)
   config.add_extra_operation_tree_class(YourOperationTree)
-  config.add_extra_diff_formatter_class(YourDiffFormatter)
 end
 ```
 

config/zeus_plan.rb

@@ -20,10 +20,15 @@ class CustomZeusPlan < Zeus::Plan
     :run_rspec_rails_test,
   )
 
-  def initialize(using_outside_of_zeus: false, color_enabled: false)
+  def initialize(
+    using_outside_of_zeus: false,
+    color_enabled: false,
+    configuration: {}
+  )
     @test_plan = TestPlan.new(
       using_outside_of_zeus: using_outside_of_zeus,
       color_enabled: color_enabled,
+      configuration: configuration,
     )
   end
 end

lib/super_diff.rb

@@ -7,6 +7,7 @@ module SuperDiff
     :ColorizedDocumentExtensions,
     "super_diff/colorized_document_extensions",
   )
+  autoload :OperationTreeFlatteners, "super_diff/operation_tree_flatteners"
   autoload :Configuration, "super_diff/configuration"
   autoload :Csi, "super_diff/csi"
   autoload :DiffFormatters, "super_diff/diff_formatters"
@@ -16,6 +17,10 @@ module SuperDiff
   autoload :GemVersion, "super_diff/gem_version"
   autoload :Helpers, "super_diff/helpers"
   autoload :ImplementationChecks, "super_diff/implementation_checks"
+  autoload :Line, "super_diff/line"
+  autoload :TieredLines, "super_diff/tiered_lines"
+  autoload :TieredLinesElider, "super_diff/tiered_lines_elider"
+  autoload :TieredLinesFormatter, "super_diff/tiered_lines_formatter"
   autoload :ObjectInspection, "super_diff/object_inspection"
   autoload :OperationTrees, "super_diff/operation_trees"
   autoload :OperationTreeBuilders, "super_diff/operation_tree_builders"
@@ -24,18 +29,25 @@ module SuperDiff
 
   def self.configure
     yield configuration
+    configuration.updated
   end
 
   def self.configuration
     @_configuration ||= Configuration.new
   end
 
-  def self.inspect_object(object, as_single_line:, indent_level: 0)
-    ObjectInspection::Inspectors::Main.call(
-      object,
-      as_single_line: as_single_line,
-      indent_level: indent_level,
-    )
+  def self.inspect_object(object, as_lines:, **rest)
+    SuperDiff::RecursionGuard.guarding_recursion_of(object) do
+      inspection_tree = ObjectInspection::InspectionTreeBuilders::Main.call(
+        object
+      )
+
+      if as_lines
+        inspection_tree.render_to_lines(object, **rest)
+      else
+        inspection_tree.render_to_string(object)
+      end
+    end
   end
 
   def self.time_like?(value)
@@ -45,6 +57,15 @@ def self.time_like?(value)
       value.is_a?(Time)
   end
 
+  def self.primitive?(value)
+    case value
+    when true, false, nil, Symbol, Numeric, Regexp, Class
+      true
+    else
+      false
+    end
+  end
+
   def self.insert_overrides(target_module, mod = nil, &block)
     if mod
       target_module.prepend(mod)

lib/super_diff/active_record.rb

@@ -2,7 +2,6 @@
 
 module SuperDiff
   module ActiveRecord
-    autoload :DiffFormatters, "super_diff/active_record/diff_formatters"
     autoload :Differs, "super_diff/active_record/differs"
     autoload(
       :ObjectInspection,
@@ -16,6 +15,10 @@ module ActiveRecord
       :OperationTreeBuilders,
       "super_diff/active_record/operation_tree_builders",
     )
+    autoload(
+      :OperationTreeFlatteners,
+      "super_diff/active_record/operation_tree_flatteners",
+    )
 
     SuperDiff.configure do |config|
       config.add_extra_differ_classes(
@@ -25,12 +28,9 @@ module ActiveRecord
         OperationTreeBuilders::ActiveRecordModel,
         OperationTreeBuilders::ActiveRecordRelation,
       )
-      config.add_extra_diff_formatter_classes(
-        DiffFormatters::ActiveRecordRelation,
-      )
-      config.add_extra_inspector_classes(
-        ObjectInspection::Inspectors::ActiveRecordModel,
-        ObjectInspection::Inspectors::ActiveRecordRelation,
+      config.add_extra_inspection_tree_builder_classes(
+        ObjectInspection::InspectionTreeBuilders::ActiveRecordModel,
+        ObjectInspection::InspectionTreeBuilders::ActiveRecordRelation,
       )
     end
   end

lib/super_diff/active_record/differs/active_record_relation.rb

@@ -7,20 +7,10 @@ def self.applies_to?(expected, actual)
             actual.is_a?(::ActiveRecord::Relation)
         end
 
-        def call
-          DiffFormatters::ActiveRecordRelation.call(
-            operation_tree,
-            indent_level: indent_level,
-          )
-        end
-
-        private
+        protected
 
-        def operation_tree
-          OperationTreeBuilders::ActiveRecordRelation.call(
-            expected: expected,
-            actual: actual,
-          )
+        def operation_tree_builder_class
+          OperationTreeBuilders::ActiveRecordRelation
         end
       end
     end

lib/super_diff/active_record/object_inspection.rb

@@ -2,12 +2,8 @@ module SuperDiff
   module ActiveRecord
     module ObjectInspection
       autoload(
-        :Inspectors,
-        "super_diff/active_record/object_inspection/inspectors",
-      )
-      autoload(
-        :MapExtension,
-        "super_diff/active_record/object_inspection/map_extension",
+        :InspectionTreeBuilders,
+        "super_diff/active_record/object_inspection/inspection_tree_builders",
       )
     end
   end

lib/super_diff/active_record/object_inspection/inspection_tree_builders.rb

@@ -0,0 +1,16 @@
+module SuperDiff
+  module ActiveRecord
+    module ObjectInspection
+      module InspectionTreeBuilders
+        autoload(
+          :ActiveRecordModel,
+          "super_diff/active_record/object_inspection/inspection_tree_builders/active_record_model",
+        )
+        autoload(
+          :ActiveRecordRelation,
+          "super_diff/active_record/object_inspection/inspection_tree_builders/active_record_relation",
+        )
+      end
+    end
+  end
+end

lib/super_diff/active_record/object_inspection/inspectors/active_record_model.rb → lib/super_diff/active_record/object_inspection/inspection_tree_builders/active_record_model.rb

@@ -1,44 +1,43 @@
 module SuperDiff
   module ActiveRecord
     module ObjectInspection
-      module Inspectors
-        class ActiveRecordModel < SuperDiff::ObjectInspection::Inspectors::Base
+      module InspectionTreeBuilders
+        class ActiveRecordModel < SuperDiff::ObjectInspection::InspectionTreeBuilders::Base
           def self.applies_to?(value)
             value.is_a?(::ActiveRecord::Base)
           end
 
-          protected
-
-          def inspection_tree
+          def call
             SuperDiff::ObjectInspection::InspectionTree.new do
-              add_text do |object|
-                "#<#{object.class} "
-              end
+              as_lines_when_rendering_to_lines(collection_bookend: :open) do
+                add_text do |object|
+                  "#<#{object.class} "
+                end
 
-              when_multiline do
-                add_text "{"
+                when_rendering_to_lines do
+                  add_text "{"
+                end
               end
 
               nested do |object|
-                add_break
-
                 insert_separated_list(
                   ["id"] + (object.attributes.keys.sort - ["id"]),
-                  separator: ",",
                 ) do |name|
-                  add_text name
-                  add_text ": "
+                  as_prefix_when_rendering_to_lines do
+                    add_text "#{name}: "
+                  end
+
                   add_inspection_of object.read_attribute(name)
                 end
               end
 
-              add_break
+              as_lines_when_rendering_to_lines(collection_bookend: :close) do
+                when_rendering_to_lines do
+                  add_text "}"
+                end
 
-              when_multiline do
-                add_text "}"
+                add_text ">"
               end
-
-              add_text ">"
             end
           end
         end

lib/super_diff/active_record/object_inspection/inspectors/active_record_relation.rb → lib/super_diff/active_record/object_inspection/inspection_tree_builders/active_record_relation.rb

@@ -1,24 +1,25 @@
 module SuperDiff
   module ActiveRecord
     module ObjectInspection
-      module Inspectors
-        class ActiveRecordRelation < SuperDiff::ObjectInspection::Inspectors::Base
+      module InspectionTreeBuilders
+        class ActiveRecordRelation < SuperDiff::ObjectInspection::InspectionTreeBuilders::Base
           def self.applies_to?(value)
             value.is_a?(::ActiveRecord::Relation)
           end
 
-          protected
-
-          def inspection_tree
+          def call
             SuperDiff::ObjectInspection::InspectionTree.new do
-              add_text "#<ActiveRecord::Relation ["
+              as_lines_when_rendering_to_lines(collection_bookend: :open) do
+                add_text "#<ActiveRecord::Relation ["
+              end
 
               nested do |array|
                 insert_array_inspection_of(array)
               end
 
-              add_break
-              add_text "]>"
+              as_lines_when_rendering_to_lines(collection_bookend: :close) do
+                add_text "]>"
+              end
             end
           end
         end

lib/super_diff/active_record/operation_tree_flatteners.rb

@@ -0,0 +1,10 @@
+module SuperDiff
+  module ActiveRecord
+    module OperationTreeFlatteners
+      autoload(
+        :ActiveRecordRelation,
+        "super_diff/active_record/operation_tree_flatteners/active_record_relation",
+      )
+    end
+  end
+end