Merge pull request #17 from JonRowe/guard_against_empty

Fix an issue caused by detecting the encoding when first data is empty
halostatue · Apr 11, 2013 · 68e1a15 · 68e1a15
2 parents 498a97c + c1373fd
commit 68e1a15
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Showing 2 changed files with 38 additions and 29 deletions.
diff --git a/lib/diff/lcs/hunk.rb b/lib/diff/lcs/hunk.rb
@@ -12,7 +12,7 @@ def initialize(data_old, data_new, piece, flag_context, file_length_difference)
     # At first, a hunk will have just one Block in it
     @blocks = [ Diff::LCS::Block.new(piece) ]
     if String.method_defined?(:encoding)
-      @preferred_data_encoding = data_old[0].encoding
+      @preferred_data_encoding = data_old.fetch(0, data_new.fetch(0,'') ).encoding
     end
     @data_old = data_old
     @data_new = data_new

diff --git a/spec/hunk_spec.rb b/spec/hunk_spec.rb
@@ -15,49 +15,58 @@ def h(v)
     let(:hunk)     { Diff::LCS::Hunk.new(old_data, new_data, pieces[0], 3, 0) }
 
     it 'should be able to produce a unified diff from the two pieces' do
-      expected =
-(<<-EOD.encode('UTF-16LE').chomp)
-@@ -1,2 +1,2 @@
--Tu avec carté {count} itém has
-+Tu avec carte {count} item has
-EOD
+      expected = (<<-EOD.gsub(/^\s+/,'').encode('UTF-16LE').chomp)
+        @@ -1,2 +1,2 @@
+        -Tu avec carté {count} itém has
+        +Tu avec carte {count} item has
+      EOD
       expect(hunk.diff(:unified).to_s == expected).to eql true
     end
 
     it 'should be able to produce a context diff from the two pieces' do
-      expected =
-(<<-EOD.encode('UTF-16LE').chomp)
-***************
-*** 1,2 ****
-!Tu avec carté {count} itém has
---- 1,2 ----
-!Tu avec carte {count} item has
-EOD
+      expected = (<<-EOD.gsub(/^\s+/,'').encode('UTF-16LE').chomp)
+        ***************
+        *** 1,2 ****
+        !Tu avec carté {count} itém has
+        --- 1,2 ----
+        !Tu avec carte {count} item has
+      EOD
 
       expect(hunk.diff(:context).to_s == expected).to eql true
     end
 
     it 'should be able to produce an old diff from the two pieces' do
-      expected =
-(<<-EOD.encode('UTF-16LE').chomp)
-1,2c1,2
-< Tu avec carté {count} itém has
----
-> Tu avec carte {count} item has
-
-EOD
+      expected = (<<-EOD.gsub(/^ +/,'').encode('UTF-16LE').chomp)
+        1,2c1,2
+        < Tu avec carté {count} itém has
+        ---
+        > Tu avec carte {count} item has
+
+      EOD
       expect(hunk.diff(:old).to_s == expected).to eql true
     end
 
     it 'should be able to produce a reverse ed diff from the two pieces' do
-      expected =
-(<<-EOD.encode('UTF-16LE').chomp)
-c1,2
-Tu avec carte {count} item has
-.
+      expected = (<<-EOD.gsub(/^ +/,'').encode('UTF-16LE').chomp)
+        c1,2
+        Tu avec carte {count} item has
+        .
 
-EOD
+      EOD
       expect(hunk.diff(:reverse_ed).to_s == expected).to eql true
     end
+
+    context 'with empty first data set' do
+      let(:old_data) { [] }
+
+      it 'should be able to produce a unified diff' do
+        expected = (<<-EOD.gsub(/^\s+/,'').encode('UTF-16LE').chomp)
+          @@ -1 +1,2 @@
+          +Tu avec carte {count} item has
+        EOD
+        expect(hunk.diff(:unified).to_s == expected).to eql true
+      end
+    end
+
   end
 end