First commit

1 files changed, 488 insertions, 0 deletions

diff --git a/pkg/gitdiff/text_test.go b/pkg/gitdiff/text_test.go
new file mode 100644
index 0000000..990b3bc
--- /dev/null
+++ b/pkg/gitdiff/text_test.go
@@ -0,0 +1,488 @@
+package gitdiff
+
+import (
+	"io"
+	"reflect"
+	"testing"
+)
+
+func TestParseTextFragmentHeader(t *testing.T) {
+	tests := map[string]struct {
+		Input  string
+		Output *TextFragment
+		Err    bool
+	}{
+		"shortest": {
+			Input: "@@ -1 +1 @@\n",
+			Output: &TextFragment{
+				OldPosition: 1,
+				OldLines:    1,
+				NewPosition: 1,
+				NewLines:    1,
+			},
+		},
+		"standard": {
+			Input: "@@ -21,5 +28,9 @@\n",
+			Output: &TextFragment{
+				OldPosition: 21,
+				OldLines:    5,
+				NewPosition: 28,
+				NewLines:    9,
+			},
+		},
+		"trailingComment": {
+			Input: "@@ -21,5 +28,9 @@ func test(n int) {\n",
+			Output: &TextFragment{
+				Comment:     "func test(n int) {",
+				OldPosition: 21,
+				OldLines:    5,
+				NewPosition: 28,
+				NewLines:    9,
+			},
+		},
+		"incomplete": {
+			Input: "@@ -12,3 +2\n",
+			Err:   true,
+		},
+		"badNumbers": {
+			Input: "@@ -1a,2b +3c,4d @@\n",
+			Err:   true,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			p := newTestParser(test.Input, true)
+
+			frag, err := p.ParseTextFragmentHeader()
+			if test.Err {
+				if err == nil || err == io.EOF {
+					t.Fatalf("expected error parsing header, but got %v", err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("error parsing header: %v", err)
+			}
+
+			if !reflect.DeepEqual(test.Output, frag) {
+				t.Errorf("incorrect fragment\nexpected: %+v\nactual: %+v", test.Output, frag)
+			}
+		})
+	}
+}
+
+func TestParseTextChunk(t *testing.T) {
+	tests := map[string]struct {
+		Input    string
+		Fragment TextFragment
+
+		Output *TextFragment
+		Err    bool
+	}{
+		"addWithContext": {
+			Input: ` context line
++new line 1
++new line 2
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 2,
+				NewLines: 4,
+			},
+			Output: &TextFragment{
+				OldLines: 2,
+				NewLines: 4,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpAdd, "new line 1\n"},
+					{OpAdd, "new line 2\n"},
+					{OpContext, "context line\n"},
+				},
+				LinesAdded:      2,
+				LeadingContext:  1,
+				TrailingContext: 1,
+			},
+		},
+		"deleteWithContext": {
+			Input: ` context line
+-old line 1
+-old line 2
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 4,
+				NewLines: 2,
+			},
+			Output: &TextFragment{
+				OldLines: 4,
+				NewLines: 2,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpDelete, "old line 1\n"},
+					{OpDelete, "old line 2\n"},
+					{OpContext, "context line\n"},
+				},
+				LinesDeleted:    2,
+				LeadingContext:  1,
+				TrailingContext: 1,
+			},
+		},
+		"replaceWithContext": {
+			Input: ` context line
+-old line 1
++new line 1
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 3,
+				NewLines: 3,
+			},
+			Output: &TextFragment{
+				OldLines: 3,
+				NewLines: 3,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpDelete, "old line 1\n"},
+					{OpAdd, "new line 1\n"},
+					{OpContext, "context line\n"},
+				},
+				LinesDeleted:    1,
+				LinesAdded:      1,
+				LeadingContext:  1,
+				TrailingContext: 1,
+			},
+		},
+		"middleContext": {
+			Input: ` context line
+-old line 1
+ context line
++new line 1
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 4,
+				NewLines: 4,
+			},
+			Output: &TextFragment{
+				OldLines: 4,
+				NewLines: 4,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpDelete, "old line 1\n"},
+					{OpContext, "context line\n"},
+					{OpAdd, "new line 1\n"},
+					{OpContext, "context line\n"},
+				},
+				LinesDeleted:    1,
+				LinesAdded:      1,
+				LeadingContext:  1,
+				TrailingContext: 1,
+			},
+		},
+		"deleteFinalNewline": {
+			Input: ` context line
+-old line 1
++new line 1
+\ No newline at end of file
+`,
+			Fragment: TextFragment{
+				OldLines: 2,
+				NewLines: 2,
+			},
+			Output: &TextFragment{
+				OldLines: 2,
+				NewLines: 2,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpDelete, "old line 1\n"},
+					{OpAdd, "new line 1"},
+				},
+				LinesDeleted:   1,
+				LinesAdded:     1,
+				LeadingContext: 1,
+			},
+		},
+		"addFinalNewline": {
+			Input: ` context line
+-old line 1
+\ No newline at end of file
++new line 1
+`,
+			Fragment: TextFragment{
+				OldLines: 2,
+				NewLines: 2,
+			},
+			Output: &TextFragment{
+				OldLines: 2,
+				NewLines: 2,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpDelete, "old line 1"},
+					{OpAdd, "new line 1\n"},
+				},
+				LinesDeleted:   1,
+				LinesAdded:     1,
+				LeadingContext: 1,
+			},
+		},
+		"addAll": {
+			Input: `+new line 1
++new line 2
++new line 3
+`,
+			Fragment: TextFragment{
+				OldLines: 0,
+				NewLines: 3,
+			},
+			Output: &TextFragment{
+				OldLines: 0,
+				NewLines: 3,
+				Lines: []Line{
+					{OpAdd, "new line 1\n"},
+					{OpAdd, "new line 2\n"},
+					{OpAdd, "new line 3\n"},
+				},
+				LinesAdded: 3,
+			},
+		},
+		"deleteAll": {
+			Input: `-old line 1
+-old line 2
+-old line 3
+`,
+			Fragment: TextFragment{
+				OldLines: 3,
+				NewLines: 0,
+			},
+			Output: &TextFragment{
+				OldLines: 3,
+				NewLines: 0,
+				Lines: []Line{
+					{OpDelete, "old line 1\n"},
+					{OpDelete, "old line 2\n"},
+					{OpDelete, "old line 3\n"},
+				},
+				LinesDeleted: 3,
+			},
+		},
+		"emptyContextLine": {
+			Input: ` context line
+
++new line
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 3,
+				NewLines: 4,
+			},
+			Output: &TextFragment{
+				OldLines: 3,
+				NewLines: 4,
+				Lines: []Line{
+					{OpContext, "context line\n"},
+					{OpContext, "\n"},
+					{OpAdd, "new line\n"},
+					{OpContext, "context line\n"},
+				},
+				LinesAdded:      1,
+				LeadingContext:  2,
+				TrailingContext: 1,
+			},
+		},
+		"emptyChunk": {
+			Input: "",
+			Err:   true,
+		},
+		"invalidOperation": {
+			Input: ` context line
+?wat line
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 3,
+				NewLines: 3,
+			},
+			Err: true,
+		},
+		"unbalancedHeader": {
+			Input: ` context line
+-old line 1
++new line 1
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 2,
+				NewLines: 5,
+			},
+			Err: true,
+		},
+		"onlyContext": {
+			Input: ` context line
+ context line
+`,
+			Fragment: TextFragment{
+				OldLines: 2,
+				NewLines: 2,
+			},
+			Err: true,
+		},
+		"unexpectedNoNewlineMarker": {
+			Input: `\ No newline at end of file`,
+			Fragment: TextFragment{
+				OldLines: 1,
+				NewLines: 1,
+			},
+			Err: true,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			p := newTestParser(test.Input, true)
+
+			frag := test.Fragment
+			err := p.ParseTextChunk(&frag)
+			if test.Err {
+				if err == nil || err == io.EOF {
+					t.Fatalf("expected error parsing text chunk, but got %v", err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("error parsing text chunk: %v", err)
+			}
+
+			if !reflect.DeepEqual(test.Output, &frag) {
+				t.Errorf("incorrect fragment\nexpected: %+v\nactual: %+v", test.Output, &frag)
+			}
+		})
+	}
+}
+
+func TestParseTextFragments(t *testing.T) {
+	tests := map[string]struct {
+		Input string
+		File  File
+
+		Fragments []*TextFragment
+		Err       bool
+	}{
+		"multipleChanges": {
+			Input: `@@ -1,3 +1,2 @@
+ context line
+-old line 1
+ context line
+@@ -8,3 +7,3 @@
+ context line
+-old line 2
++new line 1
+ context line
+@@ -15,3 +14,4 @@
+ context line
+-old line 3
++new line 2
++new line 3
+ context line
+`,
+			Fragments: []*TextFragment{
+				{
+					OldPosition: 1,
+					OldLines:    3,
+					NewPosition: 1,
+					NewLines:    2,
+					Lines: []Line{
+						{OpContext, "context line\n"},
+						{OpDelete, "old line 1\n"},
+						{OpContext, "context line\n"},
+					},
+					LinesDeleted:    1,
+					LeadingContext:  1,
+					TrailingContext: 1,
+				},
+				{
+					OldPosition: 8,
+					OldLines:    3,
+					NewPosition: 7,
+					NewLines:    3,
+					Lines: []Line{
+						{OpContext, "context line\n"},
+						{OpDelete, "old line 2\n"},
+						{OpAdd, "new line 1\n"},
+						{OpContext, "context line\n"},
+					},
+					LinesDeleted:    1,
+					LinesAdded:      1,
+					LeadingContext:  1,
+					TrailingContext: 1,
+				},
+				{
+					OldPosition: 15,
+					OldLines:    3,
+					NewPosition: 14,
+					NewLines:    4,
+					Lines: []Line{
+						{OpContext, "context line\n"},
+						{OpDelete, "old line 3\n"},
+						{OpAdd, "new line 2\n"},
+						{OpAdd, "new line 3\n"},
+						{OpContext, "context line\n"},
+					},
+					LinesDeleted:    1,
+					LinesAdded:      2,
+					LeadingContext:  1,
+					TrailingContext: 1,
+				},
+			},
+		},
+		"badNewFile": {
+			Input: `@@ -1 +1,2 @@
+-old line 1
++new line 1
++new line 2
+`,
+			File: File{
+				IsNew: true,
+			},
+			Err: true,
+		},
+		"badDeletedFile": {
+			Input: `@@ -1,2 +1 @@
+-old line 1
+ context line
+`,
+			File: File{
+				IsDelete: true,
+			},
+			Err: true,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			p := newTestParser(test.Input, true)
+
+			file := test.File
+			n, err := p.ParseTextFragments(&file)
+			if test.Err {
+				if err == nil || err == io.EOF {
+					t.Fatalf("expected error parsing text fragments, but got %v", err)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("error parsing text fragments: %v", err)
+			}
+
+			if len(test.Fragments) != n {
+				t.Fatalf("incorrect number of added fragments: expected %d, actual %d", len(test.Fragments), n)
+			}
+
+			for i, frag := range test.Fragments {
+				if !reflect.DeepEqual(frag, file.TextFragments[i]) {
+					t.Errorf("incorrect fragment at position %d\nexpected: %+v\nactual: %+v", i, frag, file.TextFragments[i])
+				}
+			}
+		})
+	}
+}