Add test for multiple files in one patch

For simplicity, use the same fragments in both of these files and in the
single file test.

Author: bluekeyes

gitdiff/parser.go

@@ -20,6 +20,8 @@ func Parse(r io.Reader) ([]*File, error) {
 		return nil, err
 	}
 
+	// TODO(bkeyes): capture non-file lines in between files
+
 	var files []*File
 	for {
 		file, err := p.ParseNextFileHeader()

gitdiff/parser_test.go

@@ -225,60 +225,83 @@ a wild fragment appears?
 }
 
 func TestParse(t *testing.T) {
+	expectedFragments := []*Fragment{
+		{
+			OldPosition: 3,
+			OldLines:    6,
+			NewPosition: 3,
+			NewLines:    8,
+			Comment:     "fragment 1",
+			Lines: []FragmentLine{
+				{OpContext, "context line\n"},
+				{OpDelete, "old line 1\n"},
+				{OpDelete, "old line 2\n"},
+				{OpContext, "context line\n"},
+				{OpAdd, "new line 1\n"},
+				{OpAdd, "new line 2\n"},
+				{OpAdd, "new line 3\n"},
+				{OpContext, "context line\n"},
+				{OpDelete, "old line 3\n"},
+				{OpAdd, "new line 4\n"},
+				{OpAdd, "new line 5\n"},
+			},
+			LinesAdded:     5,
+			LinesDeleted:   3,
+			LeadingContext: 1,
+		},
+		{
+			OldPosition: 31,
+			OldLines:    2,
+			NewPosition: 33,
+			NewLines:    2,
+			Comment:     "fragment 2",
+			Lines: []FragmentLine{
+				{OpContext, "context line\n"},
+				{OpDelete, "old line 4\n"},
+				{OpAdd, "new line 6\n"},
+			},
+			LinesAdded:     1,
+			LinesDeleted:   1,
+			LeadingContext: 1,
+		},
+	}
+
 	tests := map[string]struct {
 		InputFile string
 		Output    []*File
 		Err       bool
 	}{
-		"singleFile": {
-			InputFile: "testdata/single_file.patch",
+		"oneFile": {
+			InputFile: "testdata/one_file.patch",
 			Output: []*File{
 				{
-					OldName:      "dir/file.txt",
-					NewName:      "dir/file.txt",
+					OldName:      "dir/file1.txt",
+					NewName:      "dir/file1.txt",
 					OldMode:      os.FileMode(0100644),
 					OldOIDPrefix: "ebe9fa54",
 					NewOIDPrefix: "fe103e1d",
-					Fragments: []*Fragment{
-						{
-							OldPosition: 3,
-							OldLines:    6,
-							NewPosition: 3,
-							NewLines:    8,
-							Comment:     "fragment 1",
-							Lines: []FragmentLine{
-								{OpContext, "context line\n"},
-								{OpDelete, "old line 1\n"},
-								{OpDelete, "old line 2\n"},
-								{OpContext, "context line\n"},
-								{OpAdd, "new line 1\n"},
-								{OpAdd, "new line 2\n"},
-								{OpAdd, "new line 3\n"},
-								{OpContext, "context line\n"},
-								{OpDelete, "old line 3\n"},
-								{OpAdd, "new line 4\n"},
-								{OpAdd, "new line 5\n"},
-							},
-							LinesAdded:     5,
-							LinesDeleted:   3,
-							LeadingContext: 1,
-						},
-						{
-							OldPosition: 31,
-							OldLines:    2,
-							NewPosition: 33,
-							NewLines:    2,
-							Comment:     "fragment 2",
-							Lines: []FragmentLine{
-								{OpContext, "context line\n"},
-								{OpDelete, "old line 4\n"},
-								{OpAdd, "new line 6\n"},
-							},
-							LinesAdded:     1,
-							LinesDeleted:   1,
-							LeadingContext: 1,
-						},
-					},
+					Fragments:    expectedFragments,
+				},
+			},
+		},
+		"twoFiles": {
+			InputFile: "testdata/two_files.patch",
+			Output: []*File{
+				{
+					OldName:      "dir/file1.txt",
+					NewName:      "dir/file1.txt",
+					OldMode:      os.FileMode(0100644),
+					OldOIDPrefix: "ebe9fa54",
+					NewOIDPrefix: "fe103e1d",
+					Fragments:    expectedFragments,
+				},
+				{
+					OldName:      "dir/file2.txt",
+					NewName:      "dir/file2.txt",
+					OldMode:      os.FileMode(0100644),
+					OldOIDPrefix: "417ebc70",
+					NewOIDPrefix: "67514b7f",
+					Fragments:    expectedFragments,
 				},
 			},
 		},

gitdiff/testdata/single_file.patch renamed to gitdiff/testdata/one_file.patch

@@ -6,10 +6,10 @@ Date:   Tue Apr 2 22:55:40 2019 -0700
 
     The content is arbitrary.
 
-diff --git a/dir/file.txt b/dir/file.txt
+diff --git a/dir/file1.txt b/dir/file1.txt
 index ebe9fa54..fe103e1d 100644
---- a/dir/file.txt
-+++ b/dir/file.txt
+--- a/dir/file1.txt
++++ b/dir/file1.txt
 @@ -3,6 +3,8 @@ fragment 1
  context line
 -old line 1

gitdiff/testdata/two_files.patch

@@ -0,0 +1,57 @@
+commit 5d9790fec7d95aa223f3d20936340bf55ff3dcbe
+Author: Morton Haypenny <mhaypenny@example.com>
+Date:   Tue Apr 2 22:55:40 2019 -0700
+
+    A file with multiple fragments.
+
+    The content is arbitrary.
+
+diff --git a/dir/file1.txt b/dir/file1.txt
+index ebe9fa54..fe103e1d 100644
+--- a/dir/file1.txt
++++ b/dir/file1.txt
+@@ -3,6 +3,8 @@ fragment 1
+ context line
+-old line 1
+-old line 2
+ context line
++new line 1
++new line 2
++new line 3
+ context line
+-old line 3
++new line 4
++new line 5
+@@ -31,2 +33,2 @@ fragment 2
+ context line
+-old line 4
++new line 6
+
+commit a84b8652757d3114875388ad6d6de782f179d82a
+Author: Morton Haypenny <mhaypenny@example.com>
+Date:   Wed Apr 3 20:45:10 2019 -0700
+
+    Another file with multiple fragments.
+
+    The content is arbitrary.
+
+diff --git a/dir/file2.txt b/dir/file2.txt
+index 417ebc70..67514b7f 100644
+--- a/dir/file2.txt
++++ b/dir/file2.txt
+@@ -3,6 +3,8 @@ fragment 1
+ context line
+-old line 1
+-old line 2
+ context line
++new line 1
++new line 2
++new line 3
+ context line
+-old line 3
++new line 4
++new line 5
+@@ -31,2 +33,2 @@ fragment 2
+ context line
+-old line 4
++new line 6