fix: ensure WithTargetHeight works properly when WithRowBorder is enabled

table/target_height_test.go

@@ -396,6 +396,37 @@ func TestTargetHeightVisibleDataLinesWithSeparator(t *testing.T) {
 	assert.Greater(t, len(lines), 0, "table should not be empty")
 }
 
+// TestTargetHeightWithRowBorderNoMultilineRespectsHeight checks that enabling
+// WithRowBorder on a non-multiline table does not cause the rendered output to
+// exceed targetHeight when WithMinimumHeight is also set. Previously,
+// visibleDataLines ignored separator lines in non-multiline mode, so
+// calculatePadding added too many blank rows and the table overflowed.
+func TestTargetHeightWithRowBorderNoMultilineRespectsHeight(t *testing.T) {
+	rows := []Row{
+		shortRow(1),
+		shortRow(2),
+		shortRow(3),
+	}
+
+	const target = 12
+
+	model := New([]Column{
+		NewColumn("id", "ID", 3),
+		NewColumn("content", "Content", 20),
+	}).
+		WithRows(rows).
+		WithRowBorder(true).
+		WithTargetHeight(target).
+		WithMinimumHeight(target)
+
+	rendered := model.View()
+	lines := strings.Split(rendered, "\n")
+
+	assert.LessOrEqual(t, len(lines), target,
+		"rendered height (%d lines) exceeded target (%d)", len(lines), target)
+	assert.Greater(t, len(lines), 0, "table should not be empty")
+}
+
 // TestTargetHeightNoFooterOnSinglePage checks that no page-count footer is
 // rendered when all rows fit on a single page.
 func TestTargetHeightNoFooterOnSinglePage(t *testing.T) {

table/view.go

@@ -7,12 +7,21 @@ import (
 )
 
 // visibleDataLines returns the total terminal lines occupied by visible rows in
-// the range [startRowIndex, endRowIndex]. When multiline is disabled every row
-// is one line, so the result equals endRowIndex - startRowIndex + 1.
+// the range [startRowIndex, endRowIndex], including any separator lines between
+// rows when WithRowBorder is active.
 func (m *Model) visibleDataLines(startRowIndex, endRowIndex int) int {
 	numRows := endRowIndex - startRowIndex + 1
 
-	if !m.multiline || numRows <= 0 {
+	if numRows <= 0 {
+		return numRows
+	}
+
+	if !m.multiline {
+		if m.rowSeparator {
+			// Each pair of adjacent rows has one separator line between them.
+			return 2*numRows - 1
+		}
+
 		return numRows
 	}
 

table/view_test.go

@@ -1959,9 +1959,10 @@ func TestOuterBorderTrueMatchesDefault(t *testing.T) {
 }
 
 func TestRowBorderNoSeparatorBeforePaddingRows(t *testing.T) {
-	// WithMinimumHeight(7) with 2 data rows produces 1 padding row.
-	// The separator should appear between the two data rows but NOT
-	// between the last data row and the blank padding row.
+	// WithMinimumHeight(7) with 2 data rows and 1 separator between them
+	// occupies 3 data lines; header=3, bottom border=1 → total=7=minimumHeight.
+	// No blank padding row is needed because the separators are now counted
+	// as data lines, so the budget is already satisfied.
 	model := New([]Column{
 		NewColumn("1", "1", 4),
 		NewColumn("2", "2", 4),
@@ -1976,7 +1977,6 @@ func TestRowBorderNoSeparatorBeforePaddingRows(t *testing.T) {
 ┃   a┃   b┃
 ┣━━━━╋━━━━┫
 ┃   c┃   d┃
-┃    ┃    ┃
 ┗━━━━┻━━━━┛`
 
 	rendered := model.View()