Merge pull request #19 from lyrasis/prepend-field-with-field

add Prepend::FieldToFieldValue transform

lib/kiba/extend/transforms/prepend.rb

@@ -3,16 +3,129 @@ module Extend
     module Transforms
       module Prepend
         ::Prepend = Kiba::Extend::Transforms::Prepend
+
+        # Adds the value of prepended_field to the beginning of the value(s) of the target_field
+        #
+        # If target field value is blank, it is left blank, even if there is a prepended field value. If there is no value in prepended field, target field is left as-is
+        #
+        # == Examples
+        # Input table:
+        #
+        #  | a   | b |
+        #  -----------
+        #  | c   | d |
+        #  | e;f | g |
+        #  |     | h |
+        #  | i   |   |
+        #
+        # Used in pipeline as: 
+        #  transform Prepend::FieldToFieldValue, target_field: :a, prepended_field: :b, sep: ': '
+        #
+        # Results in:
+        #
+        #  | a      | b |
+        #  --------------
+        #  | d: c   | d |
+        #  | d: e;f | g |
+        #  |        | h |
+        #  | i      |   |
+        #
+        # Used in pipeline as: 
+        #  transform Prepend::FieldToFieldValue, target_field: :a, prepended_field: :b, sep: ': ',
+        #                                        delete_prepended: true, mvdelim: ';'
+        #
+        # Results in:
+        #
+        #  | a         |
+        #  -------------
+        #  | d: c      |
+        #  | d: e;d: f |
+        #  |           |
+        #  | i         |
+        class FieldToFieldValue
+          # @param target_field [Symbol] Name of field to prepend to
+          # @param prepended_field [Symbol] Name of field whose value should be prepended
+          # @param sep [String] Text inserted between prepended field value and target field value
+          # @param delete_prepended [Boolean] Whether or not to delete the prepended_field column after prepending
+          # @param mvdelim [String] Character(s) on which to split multiple values in target field before prepending. If empty string, behaves as a single value field
+          def initialize(target_field:, prepended_field:, sep: '', delete_prepended: false, mvdelim: '')
+            @field = target_field
+            @prepend = prepended_field
+            @sep = sep
+            @delete = delete_prepended
+            @mvdelim = mvdelim
+          end
+
+          # @private
+          def process(row)
+            fv = row.fetch(@field, nil)
+            prepend_val = row.fetch(@prepend, nil)
+            row.delete(@prepend) if @delete
+            return row if fv.blank?
+            return row if prepend_val.blank?
+
+            values = @mvdelim.blank? ? [fv] : fv.split(@mvdelim)
+            row[@field] = values.map{ |val| "#{prepend_val}#{@sep}#{val}"}
+              .join(@mvdelim)
+            row.delete(@prepend) if @delete
+            row
+          end
+        end
+
+        # Adds the specified value to the specified field
+        #
+        # If target field value is blank, it is left blank
+        #
+        # == Examples
+        # Input table:
+        #
+        #  | a   | b |
+        #  -----------
+        #  | c   | d |
+        #  | e;f | g |
+        #  |     | h |
+        #  | i   |   |
+        #
+        # Used in pipeline as: 
+        #  transform Prepend::ToFieldValue, field: :a, value: 'pre: '
+        #
+        # Results in:
+        #
+        #  | a        | b |
+        #  --------------
+        #  | pre: c   | d |
+        #  | pre: e;f | g |
+        #  |          | h |
+        #  | pre: i   |   |
+        #
+        # Used in pipeline as: 
+        #  transform Prepend::ToFieldValue, field: :a, value: 'pre: ', mvdelim: ';'
+        #
+        # Results in:
+        #
+        #  | a             | b |
+        #  ---------------------
+        #  | pre: c        | d |
+        #  | pre: e;pre: f | g |
+        #  |               | h |
+        #  | pre: i        |   |
         class ToFieldValue
-          def initialize(field:, value:)
+          # @param field [Symbol] The field to prepend to
+          # @param value [String] The value to be prepended
+          # @param mvdelim [String] Character(s) on which to split multiple values in field before prepending. If empty string, behaves as a single value field
+          def initialize(field:, value:, mvdelim: '')
             @field = field
             @value = value
+            @mvdelim = mvdelim
           end
 
+          # @private
           def process(row)
             fv = row.fetch(@field, nil)
             return row if fv.blank?
-            row[@field] = "#{@value}#{fv}"
+
+            fieldvals = @mvdelim.blank? ? [fv] : fv.split(@mvdelim)
+            row[@field] = fieldvals.map{ |fv| "#{@value}#{fv}" }.join(@mvdelim)
             row
           end
         end

lib/kiba/extend/version.rb

@@ -1,5 +1,5 @@
 module Kiba
   module Extend
-    VERSION = "1.13.0"
+    VERSION = "1.14.0"
   end
 end

spec/kiba/extend/transforms/prepend_spec.rb

@@ -1,6 +1,77 @@
 require 'spec_helper'
 
 RSpec.describe Kiba::Extend::Transforms::Prepend do
+  describe 'FieldToFieldValue' do
+    test_csv = 'tmp/test.csv'
+    rows = [
+      ['name', 'prependval'],
+      ['Weddy', 'm'],
+      [nil, 'u'],
+      ['', 'u'],
+      ['Kernel', nil],
+      ['Divebomber|Hunter', 'm']
+    ]
+
+    context 'when delete_prepended = false' do
+      before do
+        generate_csv(test_csv, rows)
+        @result = execute_job(filename: test_csv,
+                              xform: Prepend::FieldToFieldValue,
+                              xformopt: {target_field: :name, prepended_field: :prependval, sep: ': ',
+                                         mvdelim: '|'})
+      end
+      it 'prepends value of given field to existing field values' do
+        expected = {name: 'm: Weddy', prependval: 'm'}
+        expect(@result[0]).to eq(expected)
+      end
+      it 'leaves nil values alone' do
+        expected = {name: nil, prependval: 'u'}
+        expect(@result[1]).to eq(expected)
+      end
+      it 'leaves blank values alone' do
+        expected = {name: '', prependval: 'u'}
+        expect(@result[2]).to eq(expected)
+      end
+      it 'does not prepend blank field' do
+        expected = {name: 'Kernel', prependval: nil}
+        expect(@result[3]).to eq(expected)
+      end
+      it 'prepends to each multivalue in target field' do
+        expected = {name: 'm: Divebomber|m: Hunter', prependval: 'm'}
+        expect(@result[4]).to eq(expected)
+      end
+    end
+    context 'when delete_prepended = true' do
+      before do
+        generate_csv(test_csv, rows)
+        @result = execute_job(filename: test_csv,
+                              xform: Prepend::FieldToFieldValue,
+                              xformopt: {target_field: :name, prepended_field: :prependval, sep: ': ', delete_prepended: true,
+                                         mvdelim: '|'})
+      end
+      it 'prepends value of given field to existing field values' do
+        expected = {name: 'm: Weddy'}
+        expect(@result[0]).to eq(expected)
+      end
+      it 'leaves nil values alone' do
+        expected = {name: nil}
+        expect(@result[1]).to eq(expected)
+      end
+      it 'leaves blank values alone' do
+        expected = {name: ''}
+        expect(@result[2]).to eq(expected)
+      end
+      it 'does not prepend blank field' do
+        expected = {name: 'Kernel'}
+        expect(@result[3]).to eq(expected)
+      end
+      it 'prepends to each multivalue in target field' do
+        expected = {name: 'm: Divebomber|m: Hunter'}
+        expect(@result[4]).to eq(expected)
+      end
+    end
+  end
+
   describe 'ToFieldValue' do
     test_csv = 'tmp/test.csv'
     rows = [
@@ -13,8 +84,8 @@
     before do
       generate_csv(test_csv, rows)
       @result = execute_job(filename: test_csv,
-                           xform: Prepend::ToFieldValue,
-                           xformopt: {field: :name, value: 'name: '})
+                            xform: Prepend::ToFieldValue,
+                            xformopt: {field: :name, value: 'name: '})
     end
     it 'prepends given value to existing field values' do
       expected = {id: '1', name: 'name: Weddy'}