Add logic from ctran/annotate_models#868

Author: drwl

lib/annotate_rb/model_annotator.rb

@@ -26,5 +26,6 @@ module ModelAnnotator
     autoload :AnnotatedFile, "annotate_rb/model_annotator/annotated_file"
     autoload :FileParser, "annotate_rb/model_annotator/file_parser"
     autoload :ZeitwerkClassGetter, "annotate_rb/model_annotator/zeitwerk_class_getter"
+    autoload :CheckConstraintAnnotation, "annotate_rb/model_annotator/check_constraint_annotation"
   end
 end

lib/annotate_rb/model_annotator/annotation_builder.rb

@@ -44,6 +44,10 @@ def build
           @info += ForeignKeyAnnotation::AnnotationBuilder.new(@model, @options).build
         end
 
+        if @options[:show_check_constraints] && @model.table_exists?
+          @info += CheckConstraintAnnotation::AnnotationBuilder.new(@model, @options).build
+        end
+
         @info += schema_footer_text
 
         @info

lib/annotate_rb/model_annotator/check_constraint_annotation.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module AnnotateRb
+  module ModelAnnotator
+    module CheckConstraintAnnotation
+      autoload :AnnotationBuilder, "annotate_rb/model_annotator/check_constraint_annotation/annotation_builder"
+    end
+  end
+end

lib/annotate_rb/model_annotator/check_constraint_annotation/annotation_builder.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+module AnnotateRb
+  module ModelAnnotator
+    module CheckConstraintAnnotation
+      class AnnotationBuilder
+        def initialize(model, options)
+          @model = model
+          @options = options
+        end
+
+        def build
+          constraint_info = if @options[:format_markdown]
+            "#\n# ### Check Constraints\n#\n"
+          else
+            "#\n# Check Constraints\n#\n"
+          end
+
+          klass = @model.instance_variable_get(:@klass)
+
+          return "" unless klass.connection.respond_to?(:supports_check_constraints?) &&
+            klass.connection.supports_check_constraints? && klass.connection.respond_to?(:check_constraints)
+
+          check_constraints = klass.connection.check_constraints(klass.table_name)
+          return "" if check_constraints.empty?
+
+          max_size = check_constraints.map { |check_constraint| check_constraint.name.size }.max + 1
+          check_constraints.sort_by(&:name).each do |check_constraint|
+            expression = check_constraint.expression ? "(#{check_constraint.expression.squish})" : nil
+
+            constraint_info += if @options[:format_markdown]
+              cc_info_markdown = sprintf("# * `%s`", check_constraint.name)
+              cc_info_markdown += sprintf(": `%s`", expression) if expression
+              cc_info_markdown += "\n"
+
+              cc_info_markdown
+            else
+              # standard:disable Lint/FormatParameterMismatch
+              sprintf("#  %-#{max_size}.#{max_size}s %s", check_constraint.name, expression).rstrip + "\n"
+              # standard:enable Lint/FormatParameterMismatch
+            end
+          end
+
+          constraint_info
+        end
+
+        private
+      end
+    end
+  end
+end