Merge e9023a6 into 13c621d

lib/cucumber/multiline_argument/data_table.rb

@@ -336,7 +336,7 @@ def diff!(other_table, options={})
         convert_columns!
 
         original_width = cell_matrix[0].length
-        other_table_cell_matrix = pad!(other_table.cell_matrix)
+        @cell_matrix, other_table_cell_matrix = pad_and_match(@cell_matrix, other_table.cell_matrix)
         padded_width = cell_matrix[0].length
 
         missing_col = cell_matrix[0].detect{|cell| cell.status == :undefined}
@@ -556,44 +556,36 @@ def clear_cache! #:nodoc:
         @hashes = @rows_hash = @col_names = @rows = @columns = nil
       end
 
-      # Pads our own cell_matrix and returns a cell matrix of same
-      # column width that can be used for diffing
-      def pad!(other_cell_matrix) #:nodoc:
+      # Pads two cell matrices to same column width and matches columns according to header value.
+      # The first cell matrix is the reference matrix with the second matrix matched against it.
+      def pad_and_match(a_cell_matrix, other_cell_matrix) #:nodoc:
         clear_cache!
-        cols = cell_matrix.transpose
-        unmapped_cols = other_cell_matrix.transpose
+        cols = a_cell_matrix.transpose
+        unmatched_cols = other_cell_matrix.transpose
 
-        mapped_cols = []
 
-        cols.each_with_index do |col, col_index|
-          header = col[0]
-          candidate_cols, unmapped_cols = unmapped_cols.partition do |other_col|
-            other_col[0] == header
-          end
-          raise "More than one column has the header #{header}" if candidate_cols.size > 2
+        header_values = cols.map(&:first)
+        matched_cols = []
 
-          other_padded_col = if candidate_cols.size == 1
-            # Found a matching column
-            candidate_cols[0]
+        header_values.each_with_index do |v, i|
+          mapped_index = unmatched_cols.index{|unmapped_col| unmapped_col.first == v}
+          if (mapped_index)
+            matched_cols << unmatched_cols.delete_at(mapped_index)
           else
-            mark_as_missing(cols[col_index])
-            (0...other_cell_matrix.length).map do |row|
-              val = row == 0 ? header.value : nil
-              SurplusCell.new(val, self, -1)
-            end
+            mark_as_missing(cols[i])
+            empty_col = other_cell_matrix.collect {SurplusCell.new(nil, self, -1)}
+            empty_col.first.value = v
+            matched_cols << empty_col
           end
-          mapped_cols.insert(col_index, other_padded_col)
         end
 
-        unmapped_cols.each_with_index do |col, col_index|
-          empty_col = (0...cell_matrix.length).map do |row|
-            SurplusCell.new(nil, self, -1)
-          end
+
+        empty_col = cell_matrix.collect {SurplusCell.new(nil, self, -1)}
+        unmatched_cols.each do
           cols << empty_col
         end
 
-        @cell_matrix = cols.transpose
-        (mapped_cols + unmapped_cols).transpose
+        return cols.transpose, (matched_cols + unmatched_cols).transpose
       end
 
       def ensure_table(table_or_array) #:nodoc:

spec/cucumber/multiline_argument/data_table_spec.rb

@@ -316,6 +316,80 @@ module MultilineArgument
           }
         end
 
+        context "in case of duplicate header values" do
+          it "raises no error for two identical tables" do
+            t = DataTable.from(%{
+            |a|a|c|
+            |d|e|f|
+            |g|h|i|
+                               })
+            t.diff!(t.dup)
+            expect( t.to_s(:indent => 12, :color => false) ).to eq %{
+            |     a |     a |     c |
+            |     d |     e |     f |
+            |     g |     h |     i |
+          }
+          end
+
+          it "detects a diff in one cell" do
+            t1 = DataTable.from(%{
+            |a|a|c|
+            |d|e|f|
+            |g|h|i|
+                                })
+            t2 = DataTable.from(%{
+            |a|a|c|
+            |d|oops|f|
+            |g|h|i|
+                                })
+            expect{ t1.diff!(t2) }.to raise_error
+            expect( t1.to_s(:indent => 12, :color => false) ).to eq %{
+            |     a |     a    |     c |
+            | (-) d | (-) e    | (-) f |
+            | (+) d | (+) oops | (+) f |
+            |     g |     h    |     i |
+          }
+          end
+
+          it "detects missing columns" do
+            t1 = DataTable.from(%{
+            |a|a|b|c|
+            |d|d|e|f|
+            |g|g|h|i|
+                                })
+            t2 = DataTable.from(%{
+            |a|b|c|
+            |d|e|f|
+            |g|h|i|
+                                })
+            expect{ t1.diff!(t2) }.to raise_error
+            expect( t1.to_s(:indent => 12, :color => false) ).to eq %{
+            |     a | (-) a |     b |     c |
+            |     d | (-) d |     e |     f |
+            |     g | (-) g |     h |     i |
+          }
+          end
+
+          it "detects surplus columns" do
+            t1 = DataTable.from(%{
+            |a|b|c|
+            |d|e|f|
+            |g|h|i|
+                                })
+            t2 = DataTable.from(%{
+            |a|b|a|c|
+            |d|e|d|f|
+            |g|h|g|i|
+                                })
+            expect{ t1.diff!(t2, :surplus_col => true) }.to raise_error
+            expect( t1.to_s(:indent => 12, :color => false) ).to eq %{
+            |     a |     b |     c | (+) a |
+            |     d |     e |     f | (+) d |
+            |     g |     h |     i | (+) g |
+          }
+          end
+        end
+
         it "should inspect missing and surplus cells" do
           t1 = DataTable.from([
             ['name',  'male', 'lastname', 'swedish'],