Fix adjustMergeCellsHelper and add some test cases (#1082)

Signed-off-by: Dokiys <dokiychang@gmail.com>

adjust.go

@@ -208,20 +208,23 @@ func (f *File) adjustMergeCells(ws *xlsxWorksheet, dir adjustDirection, num, off
 			if y1 == num && y2 == num && offset < 0 {
 				f.deleteMergeCell(ws, i)
 				i--
+				continue
 			}
-			y1 = f.adjustMergeCellsHelper(y1, num, offset)
-			y2 = f.adjustMergeCellsHelper(y2, num, offset)
+
+			y1, y2 = f.adjustMergeCellsHelper(y1, y2, num, offset)
 		} else {
 			if x1 == num && x2 == num && offset < 0 {
 				f.deleteMergeCell(ws, i)
 				i--
+				continue
 			}
-			x1 = f.adjustMergeCellsHelper(x1, num, offset)
-			x2 = f.adjustMergeCellsHelper(x2, num, offset)
+
+			x1, x2 = f.adjustMergeCellsHelper(x1, x2, num, offset)
 		}
-		if x1 == x2 && y1 == y2 && i >= 0 {
+		if x1 == x2 && y1 == y2 {
 			f.deleteMergeCell(ws, i)
 			i--
+			continue
 		}
 		if areaData.Ref, err = f.coordinatesToAreaRef([]int{x1, y1, x2, y2}); err != nil {
 			return err
@@ -233,19 +236,34 @@ func (f *File) adjustMergeCells(ws *xlsxWorksheet, dir adjustDirection, num, off
 // adjustMergeCellsHelper provides a function for adjusting merge cells to
 // compare and calculate cell axis by the given pivot, operation axis and
 // offset.
-func (f *File) adjustMergeCellsHelper(pivot, num, offset int) int {
-	if pivot > num {
-		pivot += offset
-		if pivot < 1 {
-			return 1
-		}
-		return pivot
+func (f *File) adjustMergeCellsHelper(p1, p2, num, offset int) (int, int) {
+	if p2 < p1 {
+		p1, p2 = p2, p1
 	}
-	return pivot
+
+	if offset >= 0 {
+		if num <= p1 {
+			p1 += offset
+			p2 += offset
+		} else if num <= p2 {
+			p2 += offset
+		}
+		return p1, p2
+	}
+	if num < p1 || (num == p1 && num == p2) {
+		p1 += offset
+		p2 += offset
+	} else if num <= p2 {
+		p2 += offset
+	}
+	return p1, p2
 }
 
 // deleteMergeCell provides a function to delete merged cell by given index.
 func (f *File) deleteMergeCell(ws *xlsxWorksheet, idx int) {
+	if idx < 0 {
+		return
+	}
 	if len(ws.MergeCells.Cells) > idx {
 		ws.MergeCells.Cells = append(ws.MergeCells.Cells[:idx], ws.MergeCells.Cells[idx+1:]...)
 		ws.MergeCells.Count = len(ws.MergeCells.Cells)

adjust_test.go

@@ -45,6 +45,209 @@ func TestAdjustMergeCells(t *testing.T) {
 			},
 		},
 	}, columns, 1, -1))
+
+	// testing adjustMergeCells
+	var cases []struct {
+		lable  string
+		ws     *xlsxWorksheet
+		dir    adjustDirection
+		num    int
+		offset int
+		expect string
+	}
+
+	// testing insert
+	cases = []struct {
+		lable  string
+		ws     *xlsxWorksheet
+		dir    adjustDirection
+		num    int
+		offset int
+		expect string
+	}{
+		{
+			lable: "insert row on ref",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    rows,
+			num:    2,
+			offset: 1,
+			expect: "A3:B4",
+		},
+		{
+			lable: "insert row on bottom of ref",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    rows,
+			num:    3,
+			offset: 1,
+			expect: "A2:B4",
+		},
+		{
+			lable: "insert column on the left",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    columns,
+			num:    1,
+			offset: 1,
+			expect: "B2:C3",
+		},
+	}
+	for _, c := range cases {
+		assert.NoError(t, f.adjustMergeCells(c.ws, c.dir, c.num, 1))
+		assert.Equal(t, c.expect, c.ws.MergeCells.Cells[0].Ref, c.lable)
+	}
+
+	// testing delete
+	cases = []struct {
+		lable  string
+		ws     *xlsxWorksheet
+		dir    adjustDirection
+		num    int
+		offset int
+		expect string
+	}{
+		{
+			lable: "delete row on top of ref",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    rows,
+			num:    2,
+			offset: -1,
+			expect: "A2:B2",
+		},
+		{
+			lable: "delete row on bottom of ref",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    rows,
+			num:    3,
+			offset: -1,
+			expect: "A2:B2",
+		},
+		{
+			lable: "delete column on the ref left",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    columns,
+			num:    1,
+			offset: -1,
+			expect: "A2:A3",
+		},
+		{
+			lable: "delete column on the ref right",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A2:B3",
+						},
+					},
+				},
+			},
+			dir:    columns,
+			num:    2,
+			offset: -1,
+			expect: "A2:A3",
+		},
+	}
+	for _, c := range cases {
+		assert.NoError(t, f.adjustMergeCells(c.ws, c.dir, c.num, -1))
+		assert.Equal(t, c.expect, c.ws.MergeCells.Cells[0].Ref, c.lable)
+	}
+
+	// testing delete one row/column
+	cases = []struct {
+		lable  string
+		ws     *xlsxWorksheet
+		dir    adjustDirection
+		num    int
+		offset int
+		expect string
+	}{
+		{
+			lable: "delete one row ref",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A1:B1",
+						},
+					},
+				},
+			},
+			dir:    rows,
+			num:    1,
+			offset: -1,
+		},
+		{
+			lable: "delete one column ref",
+			ws: &xlsxWorksheet{
+				MergeCells: &xlsxMergeCells{
+					Cells: []*xlsxMergeCell{
+						{
+							Ref: "A1:A2",
+						},
+					},
+				},
+			},
+			dir:    columns,
+			num:    1,
+			offset: -1,
+		},
+	}
+	for _, c := range cases {
+		assert.NoError(t, f.adjustMergeCells(c.ws, c.dir, c.num, -1))
+		assert.Equal(t, 0, len(c.ws.MergeCells.Cells), c.lable)
+	}
+
+	f = NewFile()
+	p1, p2 := f.adjustMergeCellsHelper(2, 1, 0, 0)
+	assert.Equal(t, 1, p1)
+	assert.Equal(t, 2, p2)
+	f.deleteMergeCell(nil, -1)
 }
 
 func TestAdjustAutoFilter(t *testing.T) {
@@ -84,10 +287,6 @@ func TestAdjustHelper(t *testing.T) {
 	assert.EqualError(t, f.adjustHelper("SheetN", rows, 0, 0), "sheet SheetN is not exist")
 }
 
-func TestAdjustMergeCellsHelper(t *testing.T) {
-	assert.Equal(t, 1, NewFile().adjustMergeCellsHelper(1, 0, -2))
-}
-
 func TestAdjustCalcChain(t *testing.T) {
 	f := NewFile()
 	f.CalcChain = &xlsxCalcChain{