Initial release: pure Go mosh client and server

Wire-compatible with C mosh. AES-128-OCB3, SSP transport, fragmentation, protobuf state sync, latch extension fields. Includes ServeRW bridge mode for embedding.
2026-03-12 18:33:41 -07:00
commit bb08f71e30
19 changed files with 5445 additions and 0 deletions
@@ -0,0 +1,155 @@
+package mosh
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestFramebufferDiffIdentical(t *testing.T) {
+	fb := NewFramebuffer(80, 24)
+	old := NewFramebuffer(80, 24)
+	diff := fb.Diff(old)
+	// Should just be cursor positioning + show cursor, no cell updates.
+	if strings.Contains(string(diff), "\033[2J") {
+		t.Fatal("identical framebuffers should not trigger full clear")
+	}
+}
+
+func TestFramebufferDiffSingleCell(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(80, 24)
+	fb.CellAt(5, 3).Rune = 'A'
+	fb.CellAt(5, 3).Width = 1
+
+	diff := fb.Diff(old)
+	s := string(diff)
+	// Should contain CUP to row 4, col 6 (1-indexed).
+	if !strings.Contains(s, "\033[4;6H") {
+		t.Fatalf("expected CUP \\033[4;6H, got %q", s)
+	}
+	if !strings.Contains(s, "A") {
+		t.Fatal("diff should contain 'A'")
+	}
+}
+
+func TestFramebufferFullRedraw(t *testing.T) {
+	fb := NewFramebuffer(80, 24)
+	fb.CellAt(0, 0).Rune = 'X'
+	fb.CellAt(0, 0).Width = 1
+
+	diff := fb.Diff(nil)
+	s := string(diff)
+	if !strings.Contains(s, "\033[2J") {
+		t.Fatal("nil old should trigger full redraw with clear")
+	}
+	if !strings.Contains(s, "X") {
+		t.Fatal("full redraw should contain 'X'")
+	}
+}
+
+func TestFramebufferDiffSizeChange(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(132, 43)
+	diff := fb.Diff(old)
+	s := string(diff)
+	if !strings.Contains(s, "\033[2J") {
+		t.Fatal("size change should trigger full redraw")
+	}
+}
+
+func TestFramebufferDiffWithAttrs(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(80, 24)
+
+	c := fb.CellAt(0, 0)
+	c.Rune = 'B'
+	c.Width = 1
+	c.Attr = Attr{Bold: true, FG: Color{Type: ColorIndex, Value: 1}}
+
+	diff := fb.Diff(old)
+	s := string(diff)
+	// Should contain bold (1) and red fg (31).
+	if !strings.Contains(s, "1") {
+		t.Fatal("diff should contain bold SGR")
+	}
+	if !strings.Contains(s, "31") {
+		t.Fatal("diff should contain red FG SGR")
+	}
+	if !strings.Contains(s, "B") {
+		t.Fatal("diff should contain 'B'")
+	}
+	// Should reset at end.
+	if !strings.Contains(s, "\033[m") {
+		t.Fatal("diff should reset attributes at end")
+	}
+}
+
+func TestFramebufferDiffRGBColor(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(80, 24)
+
+	c := fb.CellAt(0, 0)
+	c.Rune = 'R'
+	c.Width = 1
+	c.Attr.FG = Color{Type: ColorRGB, Value: 0xFF8000} // orange
+
+	diff := fb.Diff(old)
+	s := string(diff)
+	if !strings.Contains(s, "38;2;255;128;0") {
+		t.Fatalf("expected RGB SGR, got %q", s)
+	}
+}
+
+func TestFramebufferDiffWideChar(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(80, 24)
+
+	// Wide character at (0,0) with continuation at (1,0).
+	fb.CellAt(0, 0).Rune = '中'
+	fb.CellAt(0, 0).Width = 2
+	fb.CellAt(1, 0).Rune = 0
+	fb.CellAt(1, 0).Width = 0
+
+	diff := fb.Diff(old)
+	s := string(diff)
+	if !strings.Contains(s, "中") {
+		t.Fatal("diff should contain wide character")
+	}
+}
+
+func TestFramebufferDiffCursorPosition(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(80, 24)
+	fb.CurX = 10
+	fb.CurY = 5
+
+	diff := fb.Diff(old)
+	s := string(diff)
+	// Final cursor position should be at row 6, col 11 (1-indexed).
+	if !strings.Contains(s, "\033[6;11H") {
+		t.Fatalf("expected cursor at [6;11H, got %q", s)
+	}
+}
+
+func TestFramebufferDiffCursorHidden(t *testing.T) {
+	old := NewFramebuffer(80, 24)
+	fb := NewFramebuffer(80, 24)
+	fb.CurVis = false
+
+	diff := fb.Diff(old)
+	s := string(diff)
+	if strings.Contains(s, "\033[?25h") {
+		t.Fatal("cursor should not be shown when CurVis=false")
+	}
+}
+
+func TestAppendCUP(t *testing.T) {
+	buf := appendCUP(nil, 0, 0)
+	if string(buf) != "\033[1;1H" {
+		t.Fatalf("got %q", string(buf))
+	}
+	buf = appendCUP(nil, 23, 79)
+	if string(buf) != "\033[24;80H" {
+		t.Fatalf("got %q", string(buf))
+	}
+}