CI's coverage gate rejected `ansi.ts` after the state normalization: the new
fold carries shapes the existing cases never reached.
Added, each expectation checked against a real terminal where the terminal is
the authority — three of my first guesses were wrong and the implementation
was right:
- `48;2;R;G;B` (the extended-background arm and its 4-parameter span), a bright
foreground and background (`91`/`101`, which resolve to `--dsw-*` tokens
rather than literal rgb), a `38` with no kind byte, re-opening an attribute
already in force, and the bare `\x1b[m` reset.
- Clearing a wide pair from the spacer side: `中x\r\bA` shows `A x`, since the
backspace clamps at column 0 and writing the lead blanks its spacer instead
of letting the `x` slide left. An erase reaching the lead does the same, so
`中x\x1b[1K|` shows three blanks before the bar.
Nine findings, one critical. Terminal cases verified in a real terminal first.
CRITICAL: cells held the accumulated SGR history, so every state boundary
re-emitted the whole chain — output switching color without a full reset
emitted O(n^2) characters. Measured: 3200 such cells produced 25 MB, and the
reviewer's ~90 KB alternating-color case is well under bash's own output cap.
State is now a normalized record (foreground, background, attribute set) with
one canonical sequence per boundary, so the emitted text is linear in cells;
the 90 KB case parses in 36 ms. That also makes the attribute closers every
chalk-based tool writes actually close: `\x1b[1mbold\x1b[22mplain` leaves the
following write PLAIN, which a real terminal confirms.
Width follows emoji presentation, not the U+2600-U+27BF block: `A✓B` redrawn
with `XY` shows `XYB`, so the check every progress line writes is ONE column.
Taking the block as wide misaligned exactly the output this card exists for.
Writing over either half of a wide pair blanks the other, since a terminal
cannot leave one cell of a two-cell glyph standing.
`line\n\x1b[0m` does not end in a newline as a string yet its last parsed line
holds nothing visible, so the terminator check now reads the parsed lines — it
had added a blank row and inflated the collapse count.
A line with no cursor movement no longer builds a column buffer at all; only
its SGR is folded, so an `ls -R` or a 5k-line log allocates nothing per
character.
The `.terminalDescription` rule had been inserted into an existing grouped
selector, silently giving `.codeBody` description typography and changing its
bottom margin from 4px to 0 — a pre-existing surface this PR does not own.
Split out, `.codeBody`'s margin restored.
Three comments contradicted their code: the fixture's exit-marker line (still
claiming recovery from a marker deliberately removed), `bash-sample`'s header
(still routing a click to the details panel, and calling the consumer's cap the
block's own), and a DetailsPanel comment stacked above the wrong rule. The
ui-primitives README documented only the CR/BS half of the replay, so a reader
would expect `OK0%` where `100%\r\x1b[KOK` renders `OK`.
CI's coverage gate caught `ansi.ts` at 95.31% branches. My local check had
scoped coverage to that one file, which measures a different test set than
the gate does — the gate is the authority and it was right.
Three branches. Two are now pinned, each verified in a real terminal first:
`ab\r` + U+0301 + `x` shows `xb` — the redraw leaves the cursor at column 0,
so a combining mark has no cell to attach to and the terminal shows nothing
for it. It also revealed that the mark was kept when `cursor` was 0, which is
fixed.
`ab\rX\x1b[31m` then a plain line shows `Xb` unstyled and the next line RED:
the mirror of the reset case, where the scan ends styled while the last cell
is not, so the convergence has to OPEN the run at the line end for it to
reach the following line.
The third was `?? ''` on a `String.split` result, which always yields at
least one element — removed rather than tested, since no input can reach it.
Eight findings, each terminal case verified in a real terminal first:
`\x1b[32mdone\rok\x1b[0m` then `plain` shows `okne` green and `plain` in the
DEFAULT color. The replay returned the last written cell's state, so a reset
landing after the final write vanished from both the text and the returned
state — and every build tool writes exactly that shape, so the color leaked
onto all later output. The replay now converges to the state the scan ended
in, which is also what it hands to the next line.
`abcd\b\x1b[1K|` shows ` |`: CSI 1K erases THROUGH the cursor column, and
the loop stopped before it. The erase mode also reads only the first
parameter now, since a terminal treats `1;2K` exactly as `1K`.
`éx\rYZ` shows `YZ`: a combining mark takes no column, so it attaches
to the cell already written instead of advancing the cursor and leaving the
`x` standing.
`中x\rA` shows `A x`: overwriting a wide character's lead cell leaves its
spacer as a blank rather than closing the gap, which would shift everything
after it one column left.
The banner lost its span when the gutter became padding — a plain block child
only reaches the content box, so the reserved column was painted in the body
color and the card's top-left radius drawn in it. Invisible in the light
theme, where banner and body share a token; visible in the dark one. The
header now pulls back across the gutter and re-insets by the same amount.
The replay trigger matches the same CSI shape the parser accepts, so a form
like `\x1b[1;2K` can no longer skip its own erase, and `replayLine`'s JSDoc
documents its new parameter and returned pair.
Docs: four places still described the dot as sitting left of the card surface,
which stopped being true when the gutter became the card's own padding, and
two fixture comments still referenced the exit marker that was deliberately
removed.
Six findings. Each terminal-semantics case was checked in a real terminal
(tmux, reading back the painted screen) before changing anything:
`100%\r\x1b[KOK` shows `OK`. Modelling the `\r` without its erase left the
previous frame's tail standing — a regression against the old truncate, since
`\r\x1b[K` is the single idiom every spinner and progress bar writes. Erase is
now part of the same replay, in all three parameter forms.
`a\tb\rXY` shows `XY b`. Counting a tab as one column produced `XYb` and
destroyed the alignment this card exists to hold, so the cursor now advances
by terminal columns: tabs reach the next 8-column stop and a wide character
takes two cells.
`\x1b[31mabc\rX\nnext` paints BOTH lines red. A newline does not reset the
graphic state, so state threads from one replayed line to the next instead of
closing at each line end.
Only `m` accumulates into a cell's style now. Folding cursor and erase
sequences in grew the state string per redraw and emitted boundaries anser
had to discard.
The empty check reads the parsed lines the card renders rather than the raw
text: output that is only escapes or control bytes survives `trim()` yet
parses to nothing, and drew blank rows plus a copy control for invisible
bytes instead of the placeholder.
The gutter is the card's own left padding rather than a margin. Every render
site rewrites `margin` wholesale for its own indent, which silently cancelled
the reservation and let a container clip the dot.
The fixture sample no longer carries an `[exit code: 1]` line: the real bash
presenter consumes that marker precisely because the card shows the exit as
its own pill, so the built-bundle snapshot had pinned a frame showing it
twice — one the product path cannot produce.
Carriage return and backspace only MOVE the cursor; neither erases. Both of
my earlier approximations were wrong, and I checked each case against a real
terminal rather than reasoning about it:
`100%\rOK` shows `OK0%`, not `OK` — the redraw is shorter than the frame
beneath it, so the tail stands. `abc\b` still shows `abc`, not `ab` — a
trailing backspace has nothing to overwrite. `\x1b[31mgone\rkept` paints
`kept` RED, because a carriage return does not reset the graphic state, which
one of my own tests had asserted the opposite of.
Both now replay into a per-line column buffer with SGR state stamped per
column, as a terminal stores it per cell. That gives the partial-overwrite
case its real result too: red `bad`, three backspaces, then `ok` shows `okd`
with the `d` still red, since `ok` reached only two of the three cells.
The presenter description now also renders at every site. An expanded row
draws it itself — the collapsed summary is hidden while open, so otherwise
the description was visible only collapsed, the opposite of "above the card"
— and the details panel draws it above the card as well.
Three of my own tests encoded the wrong semantics and were corrected with
their behavior, and the emit loop's gap-filling arm was removed as
unreachable: `\r` and backspace only move left, so no column can be unwritten.
Settled history now exposes user/assistant chrome (including date-aware
clocks) in the accessibility tree; collapse clocks via scaffold and update
keyless scenario goldens.
