Initial build: scrawl, a shared ASCII canvas over SSH
ssh in and draw on a live, shared doodle wall -- everyone connected
sees everyone else's edits in real time. Same wish+bubbletea security
model as delve-term (no shell, no exec, structurally can't reach a
real shell on the host), extended with the one thing delve-term didn't
need: multiple sessions sharing live state. wish's bm.Middleware helper
hides the *tea.Program it creates, so this builds the program directly
instead, keeping a registry (game.Canvas) that broadcasts a redraw
signal to every other connected session the instant one of them paints.
Banner generated via `figlet -f slant SCRAWL` rather than hand-drawn --
slant felt right for a doodle/scribble tool.
Two real bugs caught by actually running this with real SSH sessions,
not just unit-testing the game logic in isolation:
1. Program.Send() blocks until that program's Run() event loop is
actively reading from it. Broadcasting synchronously from inside
Join()/Paint() (including a session broadcasting to its own,
not-yet-running program on join) deadlocked every session before it
ever reached Run() -- the very first connection just hung with
nothing rendered. Fixed by sending asynchronously (go p.Send(...))
everywhere the canvas notifies sessions of a change.
2. Subtler: lipgloss's default package-level styles detect color
support from the *server process's* os.Stdout, not any given
session's actual terminal -- and a server's stdout is typically
redirected (a log file, systemd journal), so every connected session
silently lost all color/background styling at once, server-wide.
Manifested as painting a cell your own cursor already sat on being
invisible (the cursor glyph before/after looked identical, so
bubbletea's diffing renderer correctly sent zero bytes for a change
that produced no visual diff) -- confirmed via server-side debug
logging that painting itself worked correctly every time, isolating
the bug to rendering, then confirmed via a Go test that forcing a
real color profile was the difference between 0 and 1327 runes of
diff between two frames that should look different. Fixed with a
lipgloss.Renderer created per-session, bound to that session's
actual output, forced to TrueColor; cursors now highlight whatever's
already painted at that cell (background tint) rather than
replacing the character, so a session's own paint is never masked
by its own cursor marker sitting on top of it.
Verified end-to-end with two real, simultaneous SSH sessions (scripted
via pexpect): peer count syncs correctly, and one session's paint
genuinely arrives at the other via the live broadcast -- not just
unit-tested in isolation. Also verified the actual Docker image builds
and serves correctly over real SSH.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-15 19:28:17 +02:00
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package game
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import (
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"io"
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"testing"
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tea "github.com/charmbracelet/bubbletea"
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"github.com/charmbracelet/lipgloss"
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"github.com/muesli/termenv"
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)
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func TestColorAndCharSwitching(t *testing.T) {
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c := NewCanvas()
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m := NewModel(c, "test-id", "tester", newTestRenderer())
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c.Join("test-id", "tester", nil)
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// First keypress just exits the intro screen, per Update()'s own logic.
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mi, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("3")})
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m = mi.(Model)
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if m.state != stateCanvas {
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t.Fatalf("expected first keypress to exit intro, state=%v", m.state)
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}
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if m.inkColorIdx != 0 {
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t.Fatalf("expected inkColorIdx unchanged by the intro-exit keypress, got %d", m.inkColorIdx)
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}
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// Now actually press "3" for color selection.
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("3")})
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m = mi.(Model)
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if m.inkColorIdx != 2 {
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t.Fatalf("expected inkColorIdx=2 after pressing '3', got %d", m.inkColorIdx)
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}
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// Paint with the selected color.
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeySpace})
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m = mi.(Model)
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cells, cursors := c.Snapshot()
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cur := cursors["test-id"]
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painted := cells[cur.Y][cur.X]
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if painted.Char != charPalette[0] {
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t.Fatalf("expected painted char to be default charPalette[0]=%q, got %q", charPalette[0], painted.Char)
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}
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if painted.Color != inkPalette[2] {
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t.Fatalf("expected painted color to be inkPalette[2]=%q (selected via '3'), got %q", inkPalette[2], painted.Color)
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}
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}
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func TestCharCycling(t *testing.T) {
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c := NewCanvas()
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m := NewModel(c, "test-id", "tester", newTestRenderer())
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c.Join("test-id", "tester", nil)
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mi, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("x")}) // exit intro
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m = mi.(Model)
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("]")})
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m = mi.(Model)
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if m.charIdx != 1 {
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t.Fatalf("expected charIdx=1 after ']', got %d", m.charIdx)
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}
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}
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func TestViewChangesAfterMoveAwayFromPaint(t *testing.T) {
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c := NewCanvas()
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m := NewModel(c, "test-id", "tester", newTestRenderer())
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c.Join("test-id", "tester", nil)
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mi, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("x")}) // exit intro
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m = mi.(Model)
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeySpace}) // paint
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m = mi.(Model)
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viewAtPaintPosition := m.View()
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("l")}) // move right
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m = mi.(Model)
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viewAfterMove := m.View()
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if viewAtPaintPosition == viewAfterMove {
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t.Fatal("expected View() output to differ after moving away from a painted cell, but it's identical")
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}
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t.Logf("view at paint position:\n%s", viewAtPaintPosition)
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t.Logf("view after move:\n%s", viewAfterMove)
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}
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func TestMoveCursorActuallyMoves(t *testing.T) {
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c := NewCanvas()
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m := NewModel(c, "test-id", "tester", newTestRenderer())
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c.Join("test-id", "tester", nil)
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before := c.CursorsSnapshot()["test-id"]
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t.Logf("before: x=%d y=%d", before.X, before.Y)
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mi, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("x")}) // exit intro
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m = mi.(Model)
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("l")}) // move right
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m = mi.(Model)
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after := c.CursorsSnapshot()["test-id"]
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t.Logf("after: x=%d y=%d", after.X, after.Y)
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if after.X != before.X+1 {
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t.Fatalf("expected cursor X to move from %d to %d, got %d", before.X, before.X+1, after.X)
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}
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}
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// newTestRenderer forces TrueColor rather than letting lipgloss
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// auto-detect from the writer (io.Discard, like any non-*os.File writer,
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// would otherwise be treated as non-color-capable) -- matches main.go's
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// real per-session renderer setup, so these tests actually exercise the
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// same styling path a real SSH session does instead of silently testing
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// an unstyled/plain-text code path that would mask exactly this class
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// of bug.
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func newTestRenderer() *lipgloss.Renderer {
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r := lipgloss.NewRenderer(io.Discard)
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r.SetColorProfile(termenv.TrueColor)
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return r
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}
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2026-07-15 19:55:59 +02:00
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func TestCommaPeriodCharCycling(t *testing.T) {
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c := NewCanvas()
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m := NewModel(c, "test-id", "tester", newTestRenderer())
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c.Join("test-id", "tester", nil)
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mi, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("x")}) // exit intro
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m = mi.(Model)
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t.Logf("charIdx before: %d", m.charIdx)
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune(".")})
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m = mi.(Model)
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t.Logf("charIdx after '.': %d", m.charIdx)
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if m.charIdx != 1 {
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t.Fatalf("expected charIdx=1 after '.', got %d", m.charIdx)
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}
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mi, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune(",")})
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m = mi.(Model)
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t.Logf("charIdx after ',': %d", m.charIdx)
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if m.charIdx != 0 {
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t.Fatalf("expected charIdx=0 after ',', got %d", m.charIdx)
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}
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}
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