Add multivalue treatment to Append::ToFieldValue via delim parameter

CHANGELOG.adoc

@@ -40,6 +40,7 @@ These changes are merged into the `main` branch, but have not been released. Aft
 === Added
 * `MARC::LanguageCodeLookup` transform
 * Ability to pass `find` argument to `Clean::RegexpFindReplaceFieldVals` as a `Regexp` object. Not sure why this was not the default initial behavior, but here we are! (PR#196)
+* Ability to pass `delim` argument to `Append::ToFieldValue` to trigger multi-value treatment (PR#200)
 
 === Changed
 

Gemfile.lock

@@ -41,7 +41,7 @@ GEM
     coderay (1.1.3)
     concurrent-ruby (1.2.2)
     csv (3.2.6)
-    diff-lcs (1.5.0)
+    diff-lcs (1.5.1)
     docile (1.4.0)
     dry-configurable (0.15.0)
       concurrent-ruby (~> 1.0)
@@ -81,19 +81,19 @@ GEM
     rake (13.0.1)
     regexp_parser (2.8.1)
     rexml (3.2.6)
-    rspec (3.12.0)
-      rspec-core (~> 3.12.0)
-      rspec-expectations (~> 3.12.0)
-      rspec-mocks (~> 3.12.0)
-    rspec-core (3.12.2)
-      rspec-support (~> 3.12.0)
-    rspec-expectations (3.12.3)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.0)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-mocks (3.12.6)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-support (3.12.1)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.1)
     rubocop (1.56.1)
       base64 (~> 0.1.1)
       json (~> 2.3)

lib/kiba/extend/transforms/append.rb

@@ -3,99 +3,9 @@
 module Kiba
   module Extend
     module Transforms
-      # Adds values to the end of fields or rows
+      # Namespace for transforms that add values to the end of fields or rows
       module Append
         ::Append = Kiba::Extend::Transforms::Append
-
-        # Adds the given field(s) to the row with nil value if they do not
-        #   already exist in row
-        #
-        # # Examples
-        #
-        # Input table:
-        #
-        # ~~~
-        # | z  |
-        # |----|
-        # | zz |
-        # ~~~
-        #
-        # Used in pipeline as:
-        #
-        # ~~~
-        #  transform Append::NilFields, fields: %i[a b c z]
-        # ~~~
-        #
-        # Results in:
-        #
-        # ~~~
-        # | z  | a   | b   | c   |
-        # |----+-----+-----+-----|
-        # | zz | nil | nil | nil |
-        # ~~~
-        class NilFields
-          # @param fields [Array<Symbol>, Symbol] field name or list of field
-          #   names to add
-          def initialize(fields:)
-            @fields = [fields].flatten
-          end
-
-          # @param row [Hash{ Symbol => String, nil }]
-          def process(row)
-            @fields.each do |field|
-              row[field] = nil unless row.key?(field)
-            end
-            row
-          end
-        end
-
-        # Adds the given value to the end of value of the given field. Does not
-        #   affect nil/empty field values
-        #
-        # # Examples
-        #
-        # Input table:
-        #
-        # ~~~
-        # | name  |
-        # |-------|
-        # | Weddy |
-        # | nil   |
-        # |       |
-        # ~~~
-        #
-        # Used in pipeline as:
-        #
-        # ~~~
-        #  transform Append::ToFieldValue, field: :name, value: ' (name)'
-        # ~~~
-        #
-        # Results in:
-        #
-        # ~~~
-        # | name         |
-        # |--------------|
-        # | Weddy (name) |
-        # | nil          |
-        # |              |
-        # ~~~
-        class ToFieldValue
-          # @param field [Symbol] name of field to append to
-          # @param value [String] value to append to existing field values
-          def initialize(field:, value:)
-            @field = field
-            @value = value
-          end
-
-          # @param row [Hash{ Symbol => String, nil }]
-          def process(row)
-            fv = row.fetch(@field, nil)
-            return row if fv.blank?
-
-            row[@field] = "#{fv}#{@value}"
-            row
-          end
-        end
       end
     end
   end

lib/kiba/extend/transforms/append/nil_fields.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Kiba
+  module Extend
+    module Transforms
+      module Append
+        # Adds the given field(s) to the row with nil value if they do not
+        #   already exist in row
+        #
+        # @example
+        #   # Used in pipeline as:
+        #   # transform Append::NilFields, fields: %i[a b z]
+        #
+        #   xform = Append::NilFields.new(fields: %i[a b z])
+        #   input = [{z: "zz"}]
+        #   result = input.map{ |row| xform.process(row) }
+        #   expected = [{z: "zz", a: nil, b: nil}]
+        #   expect(result).to eq(expected)
+        class NilFields
+          # @param fields [Array<Symbol>, Symbol] field name or list of field
+          #   names to add
+          def initialize(fields:)
+            @fields = [fields].flatten
+          end
+
+          # @param row [Hash{ Symbol => String, nil }]
+          def process(row)
+            @fields.each do |field|
+              row[field] = nil unless row.key?(field)
+            end
+            row
+          end
+        end
+      end
+    end
+  end
+end

lib/kiba/extend/transforms/append/to_field_value.rb

@@ -0,0 +1,78 @@
+# frozen_string_literal: true
+
+module Kiba
+  module Extend
+    module Transforms
+      module Append
+        # Adds the given value to the end of value of the given field. Does not
+        #   affect nil/empty field values
+        #
+        # @example Treated as single value (default)
+        #   # Used in pipeline as:
+        #   # transform Append::ToFieldValue, field: :name, value: " (name)"
+        #
+        #   xform = Append::ToFieldValue.new(field: :name, value: " (name)")
+        #   input = [
+        #       {name: "Weddy"},
+        #       {name: "Kernel|Zipper"},
+        #       {name: nil},
+        #       {name: ""}
+        #     ]
+        #   result = input.map{ |row| xform.process(row) }
+        #   expected = [
+        #       {name: "Weddy (name)"},
+        #       {name: "Kernel|Zipper (name)"},
+        #       {name: nil},
+        #       {name: ""}
+        #     ]
+        #   expect(result).to eq(expected)
+        #
+        # @example Treated as multivalue
+        #   # Used in pipeline as:
+        #   # transform Append::ToFieldValue,
+        #   #   field: :name,
+        #   #   value: " (name)",
+        #   #   delim: "|"
+        #
+        #   xform = Append::ToFieldValue.new(field: :name, value: " (name)",
+        #     delim: "|")
+        #   input = [
+        #       {name: "Weddy"},
+        #       {name: "Kernel|Zipper"},
+        #       {name: nil},
+        #       {name: ""}
+        #     ]
+        #   result = input.map{ |row| xform.process(row) }
+        #   expected = [
+        #       {name: "Weddy (name)"},
+        #       {name: "Kernel (name)|Zipper (name)"},
+        #       {name: nil},
+        #       {name: ""}
+        #     ]
+        #   expect(result).to eq(expected)
+        class ToFieldValue
+          # @param field [Symbol] name of field to append to
+          # @param value [String] value to append to existing field values
+          # @param delim [String, nil] indicates multivalue delimiter on which
+          #   to split values, if given
+          def initialize(field:, value:, delim: nil)
+            @field = field
+            @value = value
+            @delim = delim
+          end
+
+          # @param row [Hash{ Symbol => String, nil }]
+          def process(row)
+            fv = row.fetch(@field, nil)
+            return row if fv.blank?
+
+            vals = @delim ? fv.split(@delim) : [fv]
+            row[@field] = vals.map { |fieldval| "#{fieldval}#{@value}" }
+              .join(@delim)
+            row
+          end
+        end
+      end
+    end
+  end
+end