Wrap long edit diff lines

commit: 734bf87c9c178aba726e72a7c4597445d46986c3
author: patriceckhart · 3mo ago · 2026-07-23 12:23 UTC
parent: 09b92ac
signature: unsigned

2 files · +146 -54

M packages/tui/view.go +77 -54


@@ -1549,15 +1549,15 @@ func (v *View) renderToolText(text string, width, defaultColor int, sourcePath s
1549	1549		if inDiff && len(l) > 0 {
1550	1550		switch l[0] {
1551	1551		case '+':
1552		-	out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath))
	1552	+	out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath)...)
1553	1553		newLine++
1554	1554		continue
1555	1555		case '-':
1556		-	out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath))
	1556	+	out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath)...)
1557	1557		oldLine++
1558	1558		continue
1559	1559		case ' ':
1560		-	out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath))
	1560	+	out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath)...)
1561	1561		oldLine++
1562	1562		newLine++
1563	1563		continue

@@ -1613,34 +1613,17 @@ func parseHunkHeader(l string) (oldStart, newStart int, ok bool) {
1613	1613		return o, n, true
1614	1614		}
1615	1615
1616		-	// renderDiffRow renders one unified-diff line with a read-style gutter
1617		-	// (6-cell right-aligned line number, muted) followed by the +/-/space
1618		-	// marker and the code. Code is syntax-highlighted if sourcePath hints
1619		-	// at a known language; falls back to the plain diff color otherwise.
1620		-	func (v *View) renderDiffRow(line string, width, color int, lineNo int, mark byte, sourcePath string) string {
	1616	+	// renderDiffRow renders one unified-diff source line as one or more visual
	1617	+	// rows. The first row carries the read-style line-number gutter; continuation
	1618	+	// rows use a blank gutter so wrapped content cannot be mistaken for another
	1619	+	// source line. Code is syntax-highlighted if sourcePath hints at a known
	1620	+	// language and otherwise uses the diff color.
	1621	+	func (v *View) renderDiffRow(line string, width, color int, lineNo int, mark byte, sourcePath string) []string {
1621	1622		if len(line) == 0 {
1622		-	return ""
	1623	+	return []string{""}
1623	1624		}
1624	1625		code := expandTabs(line[1:]) // strip the leading marker; expand tabs
1625	1626
1626		-	// Syntax-highlight the code half when we know the language. Use
1627		-	// the same HighlightCode pipeline as renderNumberedFile so the
1628		-	// palette matches.
1629		-	lang := LanguageFromPath(sourcePath)
1630		-	var codeRendered string
1631		-	if lang != "" {
1632		-	if h := v.Theme.HighlightCode(code, lang); len(h) == 1 {
1633		-	codeRendered = h[0]
1634		-	}
1635		-	}
1636		-	if codeRendered == "" {
1637		-	if mark == ' ' {
1638		-	codeRendered = v.Theme.FG256(v.Theme.Muted, code)
1639		-	} else {
1640		-	codeRendered = v.Theme.FG256(color, code)
1641		-	}
1642		-	}
1643		-
1644	1627		// Gutter shape: sign + number share a color so they read as one
1645	1628		// visual token ("+123") instead of a neutral line number next to
1646	1629		// a stray marker. Unchanged context lines get a muted gutter and

@@ -1655,39 +1638,79 @@ func (v *View) renderDiffRow(line string, width, color int, lineNo int, mark byt
1655	1638		default:
1656	1639		gutterText = fmt.Sprintf(" %3d ", lineNo)
1657	1640		}
1658		-	var gutter string
	1641	+	gutterColor := color
1659	1642		if mark == ' ' {
1660		-	gutter = v.Theme.FG256(v.Theme.Muted, gutterText)
1661		-	} else {
1662		-	gutter = v.Theme.FG256(color, gutterText)
	1643	+	gutterColor = v.Theme.Muted
1663	1644		}
1664		-	row := " " + gutter + codeRendered
1665	1645
1666		-	// Cheap width clamp: truncate visible text if the raw code is too
1667		-	// long. We work on the pre-ANSI code string because measuring ansi
1668		-	// output is unreliable.
1669		-	maxCode := width - 4 /* indent / - 7 / gutter (sign+5 digits+tab) */
1670		-	if maxCode > 0 && len(code) > maxCode {
1671		-	trunc := strings.Repeat(".", maxCode)
1672		-	if maxCode > 3 {
1673		-	trunc = code[:maxCode-3] + "..."
	1646	+	maxCode := width - visibleWidth(" "+gutterText)
	1647	+	if maxCode < 1 {
	1648	+	maxCode = 1
	1649	+	}
	1650	+	chunks := wrapCodeLine(code, maxCode)
	1651	+	lang := LanguageFromPath(sourcePath)
	1652	+	out := make([]string, 0, len(chunks))
	1653	+	for i, chunk := range chunks {
	1654	+	rowGutter := gutterText
	1655	+	if i > 0 {
	1656	+	rowGutter = strings.Repeat(" ", visibleWidth(gutterText))
1674	1657		}
	1658	+	codeRendered := ""
1675	1659		if lang != "" {
1676		-	if h := v.Theme.HighlightCode(trunc, lang); len(h) == 1 {
	1660	+	if h := v.Theme.HighlightCode(chunk, lang); len(h) == 1 {
1677	1661		codeRendered = h[0]
1678		-	} else if mark == ' ' {
1679		-	codeRendered = v.Theme.FG256(v.Theme.Muted, trunc)
1680		-	} else {
1681		-	codeRendered = v.Theme.FG256(color, trunc)
1682	1662		}
1683		-	} else if mark == ' ' {
1684		-	codeRendered = v.Theme.FG256(v.Theme.Muted, trunc)
1685		-	} else {
1686		-	codeRendered = v.Theme.FG256(color, trunc)
1687	1663		}
1688		-	row = " " + gutter + codeRendered
	1664	+	if codeRendered == "" {
	1665	+	codeColor := color
	1666	+	if mark == ' ' {
	1667	+	codeColor = v.Theme.Muted
	1668	+	}
	1669	+	codeRendered = v.Theme.FG256(codeColor, chunk)
	1670	+	}
	1671	+	out = append(out, " "+v.Theme.FG256(gutterColor, rowGutter)+codeRendered)
	1672	+	}
	1673	+	return out
	1674	+	}
	1675	+
	1676	+	// wrapCodeLine splits code to a terminal cell width without dropping any
	1677	+	// characters. It prefers breaking after whitespace, then falls back to a hard
	1678	+	// rune boundary for long tokens. Keeping the whitespace on the preceding row
	1679	+	// means joining the returned chunks reconstructs the expanded source exactly.
	1680	+	func wrapCodeLine(line string, width int) []string {
	1681	+	if width < 1 \|\| visibleWidth(line) <= width {
	1682	+	return []string{line}
	1683	+	}
	1684	+	runes := []rune(line)
	1685	+	var out []string
	1686	+	for start := 0; start < len(runes); {
	1687	+	cells := 0
	1688	+	end := start
	1689	+	lastBreak := -1
	1690	+	for end < len(runes) {
	1691	+	runeWidth := runewidth.RuneWidth(runes[end])
	1692	+	if cells+runeWidth > width && end > start {
	1693	+	break
	1694	+	}
	1695	+	cells += runeWidth
	1696	+	end++
	1697	+	if runes[end-1] == ' ' \|\| runes[end-1] == '\t' {
	1698	+	lastBreak = end
	1699	+	}
	1700	+	if cells >= width {
	1701	+	break
	1702	+	}
	1703	+	}
	1704	+	if end == start { // A rune wider than the requested width.
	1705	+	end++
	1706	+	}
	1707	+	if end < len(runes) && lastBreak > start {
	1708	+	end = lastBreak
	1709	+	}
	1710	+	out = append(out, string(runes[start:end]))
	1711	+	start = end
1689	1712		}
1690		-	return row
	1713	+	return out
1691	1714		}
1692	1715
1693	1716		// renderImageBlock returns the lines for one image, inline if possible.

@@ -2048,13 +2071,13 @@ func (v *View) renderUnifiedDiff(text string, width int, sourcePath string) []st
2048	2071		}
2049	2072		switch l[0] {
2050	2073		case '+':
2051		-	out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath))
	2074	+	out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath)...)
2052	2075		newLine++
2053	2076		case '-':
2054		-	out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath))
	2077	+	out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath)...)
2055	2078		oldLine++
2056	2079		case ' ':
2057		-	out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath))
	2080	+	out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath)...)
2058	2081		oldLine++
2059	2082		newLine++
2060	2083		default:

 		if inDiff && len(l) > 0 {
 			switch l[0] {
 			case '+':
-				out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath))
+				out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath)...)
 				newLine++
 				continue
 			case '-':
-				out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath))
+				out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath)...)
 				oldLine++
 				continue
 			case ' ':
-				out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath))
+				out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath)...)
 				oldLine++
 				newLine++
 				continue
 	return o, n, true
 }
-// renderDiffRow renders one unified-diff line with a read-style gutter
+// renderDiffRow renders one unified-diff source line as one or more visual
-// (6-cell right-aligned line number, muted) followed by the +/-/space
+// rows. The first row carries the read-style line-number gutter; continuation
-// marker and the code. Code is syntax-highlighted if sourcePath hints
+// rows use a blank gutter so wrapped content cannot be mistaken for another
-// at a known language; falls back to the plain diff color otherwise.
+// source line. Code is syntax-highlighted if sourcePath hints at a known
-func (v *View) renderDiffRow(line string, width, color int, lineNo int, mark byte, sourcePath string) string {
+// language and otherwise uses the diff color.
+func (v *View) renderDiffRow(line string, width, color int, lineNo int, mark byte, sourcePath string) []string {
 	if len(line) == 0 {
-		return ""
+		return []string{""}
 	}
 	code := expandTabs(line[1:]) // strip the leading marker; expand tabs
-	// Syntax-highlight the code half when we know the language. Use
-	// the same HighlightCode pipeline as renderNumberedFile so the
-	// palette matches.
-	lang := LanguageFromPath(sourcePath)
-	var codeRendered string
-	if lang != "" {
-		if h := v.Theme.HighlightCode(code, lang); len(h) == 1 {
-			codeRendered = h[0]
-		}
-	}
-	if codeRendered == "" {
-		if mark == ' ' {
-			codeRendered = v.Theme.FG256(v.Theme.Muted, code)
-		} else {
-			codeRendered = v.Theme.FG256(color, code)
-		}
-	}
 	// Gutter shape: sign + number share a color so they read as one
 	// visual token ("+123") instead of a neutral line number next to
 	// a stray marker. Unchanged context lines get a muted gutter and
 	default:
 		gutterText = fmt.Sprintf(" %3d ", lineNo)
 	}
-	var gutter string
+	gutterColor := color
 	if mark == ' ' {
-		gutter = v.Theme.FG256(v.Theme.Muted, gutterText)
+		gutterColor = v.Theme.Muted
-	} else {
-		gutter = v.Theme.FG256(color, gutterText)
 	}
-	row := "    " + gutter + codeRendered
-	// Cheap width clamp: truncate visible text if the raw code is too
+	maxCode := width - visibleWidth("    "+gutterText)
-	// long. We work on the pre-ANSI code string because measuring ansi
+	if maxCode < 1 {
-	// output is unreliable.
+		maxCode = 1
-	maxCode := width - 4 /* indent */ - 7 /* gutter (sign+5 digits+tab) */
+	}
-	if maxCode > 0 && len(code) > maxCode {
+	chunks := wrapCodeLine(code, maxCode)
-		trunc := strings.Repeat(".", maxCode)
+	lang := LanguageFromPath(sourcePath)
-		if maxCode > 3 {
+	out := make([]string, 0, len(chunks))
-			trunc = code[:maxCode-3] + "..."
+	for i, chunk := range chunks {
+		rowGutter := gutterText
+		if i > 0 {
+			rowGutter = strings.Repeat(" ", visibleWidth(gutterText))
 		}
+		codeRendered := ""
 		if lang != "" {
-			if h := v.Theme.HighlightCode(trunc, lang); len(h) == 1 {
+			if h := v.Theme.HighlightCode(chunk, lang); len(h) == 1 {
 				codeRendered = h[0]
-			} else if mark == ' ' {
-				codeRendered = v.Theme.FG256(v.Theme.Muted, trunc)
-			} else {
-				codeRendered = v.Theme.FG256(color, trunc)
 			}
-		} else if mark == ' ' {
-			codeRendered = v.Theme.FG256(v.Theme.Muted, trunc)
-		} else {
-			codeRendered = v.Theme.FG256(color, trunc)
 		}
-		row = "    " + gutter + codeRendered
+		if codeRendered == "" {
+			codeColor := color
+			if mark == ' ' {
+				codeColor = v.Theme.Muted
+			}
+			codeRendered = v.Theme.FG256(codeColor, chunk)
+		}
+		out = append(out, "    "+v.Theme.FG256(gutterColor, rowGutter)+codeRendered)
+	}
+	return out
+}
+// wrapCodeLine splits code to a terminal cell width without dropping any
+// characters. It prefers breaking after whitespace, then falls back to a hard
+// rune boundary for long tokens. Keeping the whitespace on the preceding row
+// means joining the returned chunks reconstructs the expanded source exactly.
+func wrapCodeLine(line string, width int) []string {
+	if width < 1 || visibleWidth(line) <= width {
+		return []string{line}
+	}
+	runes := []rune(line)
+	var out []string
+	for start := 0; start < len(runes); {
+		cells := 0
+		end := start
+		lastBreak := -1
+		for end < len(runes) {
+			runeWidth := runewidth.RuneWidth(runes[end])
+			if cells+runeWidth > width && end > start {
+				break
+			}
+			cells += runeWidth
+			end++
+			if runes[end-1] == ' ' || runes[end-1] == '\t' {
+				lastBreak = end
+			}
+			if cells >= width {
+				break
+			}
+		}
+		if end == start { // A rune wider than the requested width.
+			end++
+		}
+		if end < len(runes) && lastBreak > start {
+			end = lastBreak
+		}
+		out = append(out, string(runes[start:end]))
+		start = end
 	}
-	return row
+	return out
 }
 // renderImageBlock returns the lines for one image, inline if possible.
 		}
 		switch l[0] {
 		case '+':
-			out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath))
+			out = append(out, v.renderDiffRow(l, width, v.Theme.Tool, newLine, '+', sourcePath)...)
 			newLine++
 		case '-':
-			out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath))
+			out = append(out, v.renderDiffRow(l, width, v.Theme.Error, oldLine, '-', sourcePath)...)
 			oldLine++
 		case ' ':
-			out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath))
+			out = append(out, v.renderDiffRow(l, width, v.Theme.Muted, newLine, ' ', sourcePath)...)
 			oldLine++
 			newLine++
 		default:

A packages/tui/view_diff_wrap_test.go +69 -0

@@ -0,0 +1,69 @@
	1	+	package tui
	2	+
	3	+	import (
	4	+	"strings"
	5	+	"testing"
	6	+	)
	7	+
	8	+	func TestRenderDiffRowWrapsWithoutLosingContent(t *testing.T) {
	9	+	const width = 30
	10	+	code := `const message = "alpha beta gamma delta epsilon"`
	11	+	v := View{Theme: Dark}
	12	+
	13	+	rows := v.renderDiffRow("+"+code, width, v.Theme.Tool, 7, '+', "sample.go")
	14	+	if len(rows) < 2 {
	15	+	t.Fatalf("long diff line did not wrap: %q", rows)
	16	+	}
	17	+
	18	+	var rebuilt strings.Builder
	19	+	for i, row := range rows {
	20	+	plain := stripANSI(row)
	21	+	if got := visibleWidth(row); got > width {
	22	+	t.Errorf("row %d width = %d, want <= %d: %q", i, got, width, plain)
	23	+	}
	24	+	prefix := " "
	25	+	if i == 0 {
	26	+	prefix = " + 7 "
	27	+	}
	28	+	if !strings.HasPrefix(plain, prefix) {
	29	+	t.Fatalf("row %d prefix = %q, want %q", i, plain, prefix)
	30	+	}
	31	+	rebuilt.WriteString(strings.TrimPrefix(plain, prefix))
	32	+	}
	33	+	if got := rebuilt.String(); got != code {
	34	+	t.Fatalf("wrapped content changed:\n got: %q\nwant: %q", got, code)
	35	+	}
	36	+	if strings.Contains(stripANSI(strings.Join(rows, "\n")), "...") {
	37	+	t.Fatalf("wrapped diff still contains truncation ellipsis: %q", rows)
	38	+	}
	39	+	}
	40	+
	41	+	func TestRenderDiffRowWrapsUnicodeByDisplayWidth(t *testing.T) {
	42	+	const width = 18
	43	+	code := "名前 = 🙂🙂🙂 café résumé"
	44	+	v := View{Theme: Dark}
	45	+
	46	+	rows := v.renderDiffRow("-"+code, width, v.Theme.Error, 12, '-', "")
	47	+	if len(rows) < 2 {
	48	+	t.Fatalf("long Unicode diff line did not wrap: %q", rows)
	49	+	}
	50	+
	51	+	var rebuilt strings.Builder
	52	+	for i, row := range rows {
	53	+	plain := stripANSI(row)
	54	+	if got := visibleWidth(row); got > width {
	55	+	t.Errorf("row %d width = %d, want <= %d: %q", i, got, width, plain)
	56	+	}
	57	+	prefix := " "
	58	+	if i == 0 {
	59	+	prefix = " - 12 "
	60	+	}
	61	+	if !strings.HasPrefix(plain, prefix) {
	62	+	t.Fatalf("row %d prefix = %q, want %q", i, plain, prefix)
	63	+	}
	64	+	rebuilt.WriteString(strings.TrimPrefix(plain, prefix))
	65	+	}
	66	+	if got := rebuilt.String(); got != code {
	67	+	t.Fatalf("wrapped Unicode content changed:\n got: %q\nwant: %q", got, code)
	68	+	}
	69	+	}

@@ -0,0 +1,69 @@
	1	+	package tui
	2	+
	3	+	import (
	4	+	"strings"
	5	+	"testing"
	6	+	)
	7	+
	8	+	func TestRenderDiffRowWrapsWithoutLosingContent(t *testing.T) {
	9	+	const width = 30
	10	+	code := `const message = "alpha beta gamma delta epsilon"`
	11	+	v := View{Theme: Dark}
	12	+
	13	+	rows := v.renderDiffRow("+"+code, width, v.Theme.Tool, 7, '+', "sample.go")
	14	+	if len(rows) < 2 {
	15	+	t.Fatalf("long diff line did not wrap: %q", rows)
	16	+	}
	17	+
	18	+	var rebuilt strings.Builder
	19	+	for i, row := range rows {
	20	+	plain := stripANSI(row)
	21	+	if got := visibleWidth(row); got > width {
	22	+	t.Errorf("row %d width = %d, want <= %d: %q", i, got, width, plain)
	23	+	}
	24	+	prefix := " "
	25	+	if i == 0 {
	26	+	prefix = " + 7 "
	27	+	}
	28	+	if !strings.HasPrefix(plain, prefix) {
	29	+	t.Fatalf("row %d prefix = %q, want %q", i, plain, prefix)
	30	+	}
	31	+	rebuilt.WriteString(strings.TrimPrefix(plain, prefix))
	32	+	}
	33	+	if got := rebuilt.String(); got != code {
	34	+	t.Fatalf("wrapped content changed:\n got: %q\nwant: %q", got, code)
	35	+	}
	36	+	if strings.Contains(stripANSI(strings.Join(rows, "\n")), "...") {
	37	+	t.Fatalf("wrapped diff still contains truncation ellipsis: %q", rows)
	38	+	}
	39	+	}
	40	+
	41	+	func TestRenderDiffRowWrapsUnicodeByDisplayWidth(t *testing.T) {
	42	+	const width = 18
	43	+	code := "名前 = 🙂🙂🙂 café résumé"
	44	+	v := View{Theme: Dark}
	45	+
	46	+	rows := v.renderDiffRow("-"+code, width, v.Theme.Error, 12, '-', "")
	47	+	if len(rows) < 2 {
	48	+	t.Fatalf("long Unicode diff line did not wrap: %q", rows)
	49	+	}
	50	+
	51	+	var rebuilt strings.Builder
	52	+	for i, row := range rows {
	53	+	plain := stripANSI(row)
	54	+	if got := visibleWidth(row); got > width {
	55	+	t.Errorf("row %d width = %d, want <= %d: %q", i, got, width, plain)
	56	+	}
	57	+	prefix := " "
	58	+	if i == 0 {
	59	+	prefix = " - 12 "
	60	+	}
	61	+	if !strings.HasPrefix(plain, prefix) {
	62	+	t.Fatalf("row %d prefix = %q, want %q", i, plain, prefix)
	63	+	}
	64	+	rebuilt.WriteString(strings.TrimPrefix(plain, prefix))
	65	+	}
	66	+	if got := rebuilt.String(); got != code {
	67	+	t.Fatalf("wrapped Unicode content changed:\n got: %q\nwant: %q", got, code)
	68	+	}
	69	+	}