DepartureRow

No Base UI part, so nothing from Base UI here: the row is read, not operated. It takes no focus, and no key does anything (CR-8).

A live departure reads "5C, Husum Torv, Live, 4 min, 08:14, On time", and an estimated one "5C, Husum Torv, Estimated, 6 min, 08:16, 3 min late": the word "Estimated" tells the ear what the "~" tells the eye. A cancelled one reads "5C, Husum Torv, Cancelled, 4 min, 08:14": the strike-through is not read, so "Cancelled", read before the countdown, tells the ear what the line through it tells the eye. An interval reads "M2, Lufthavnen, Live, Every 3 to 4 min", and a train with its track "RE, Helsingør, Timetable only, Track 4, 18 min, 08:26, Delay unknown".

A departure two minutes late reads "5C, Husum Torv, Live, 6 min, Timetabled 08:14, 08:16, 2 min late": "Timetabled", read before the struck time, tells the ear what the line through it tells the eye, and the time after it is the one the row shows; an estimated one reads the same after "Estimated", which says the "~" before 08:16 (CR-16).

What axe won't catch, from the contract, each with how this component meets it:

• Everything the eye is told, the ear is told, for every shape each prop accepts: the line's colour is named by lineName, read from the badge; the dot's shape by the state's word beside it, read once, since the dot is aria-hidden (CR-6); the "~" by that word, "Estimated", "Timetable only" or "No signal" (CR-4); the countdown by its figure and "min", or "Now"; an unknown countdown by "Unknown" (CR-3); the delay by Delay's own words, and a timetable-only or no-signal vehicle's "—" by "Delay unknown" (CR-5); a cancelled row's strike-through and danger colour by "Cancelled" (CR-13); the timetabled time struck through before an expected one by "Timetabled", and an estimated expected time's "~" by the state's word (CR-16); an interval by its words, read whole (CR-14).
• Every landmark and named region has an accessible name: none here; the row is no region, and a list of rows is the caller's.
• Every default label can be overridden: nowLabel, unknownLabel, timetabledTimeLabel, cancelledLabel, everyLabel, everyRangeLabel, the five state labels from liveLabel to noSignalLabel, and Delay's five, minutesUnitLabel, minutesLateLabel, minutesEarlyLabel, onTimeLabel and delayUnknownLabel.
• Every shape the type accepts renders, in every variant: lineName and destination render a string, an element and a list alike; countdown positive, under 45 seconds, zero, negative, fractional (rounded) and not finite (CR-3); time given and left out; expected given, left out, empty, the same as time and with time left out, in every variant, cancelled and with an interval (CR-16); delay a number, null and left out, in every variant; a long destination wraps under itself (CR-9); interval one number, a range, a range given high to low, a range whose ends round alike, and not finite (CR-14); cancelled with a countdown and with an interval (CR-13); platform a string and an element, beside a long state's word at 320 px (CR-15).
• A hidden copy kept for animation is aria-hidden, and a collapsed region is inert: none here; nothing animates or collapses. The dot and the "~" are aria-hidden because a word says them, not for animation.
• Native semantics first: plain divs and spans, a <time> for the time, and the composed components' own; no ARIA but aria-hidden on the dot, the "~", the unknown "—" and the struck timetabled time, which its hidden words say. A cancelled countdown and time, and a timetabled time an expected one replaces, are struck through by CSS, not wrapped in <s> or <del>, which screen readers announce unevenly or not at all; the word "Cancelled" carries it.
• Focus moves in reading order and returns on close: the row takes no focus; its DOM order, badge, destination, state, platform, countdown or interval, time, expected time and delay, is its reading order on screen.
• Every target is at least size.target-min square: no target; the row is not pressed (CR-8).
• Loops stop when the system asks for less motion: none here; nothing moves. A countdown that changes is new props from the screen, not an animation.

The line's name, the destination, the times and the platform are the caller's data; the countdown's words, the interval's words, the state's word and "Cancelled" are the row's own, and Delay's words are Delay's, overridable here through the props above. Each word is a text run of its own, apart from any figure, so expectOwnedStrings reads it as a dictionary value, except the interval's, one template filled with its figures, which expectOwnedStrings matches against the template.

The row adds one owned string, now, "Now", with the Danish "Nu", the Swedish "Nu" and the Norwegian "Nå", outside content design's table of data-state, delay and disruption words. Content design writes "Countdowns under 45 seconds read 'Now'", no key in packages/perron/src/locale/en.ts says it, and it is a countdown's word rather than a data-state, delay or disruption word, as StopTimeline's "Next stop" stayed out of the table.

now joins en.ts with the JSDoc "A departure's countdown: shown and announced in place of the minutes when it leaves in under 45 seconds.", and its Danish, Swedish and Norwegian in da.ts, sv.ts and nb.ts.

The three later additions brought three more, each new, since no key in en.ts said them, each with a JSDoc in en.ts that says where it shows:

• cancelled, "Cancelled", with the Danish "Aflyst", the Swedish "Inställd" and the Norwegian "Innstilt". It is named for what it says, not for the row, since StopTimeline's cancelled stops will say the same word; and it joins content design's table, as a word every screen that shows a cancelled trip must agree on, as it does the delay and disruption words.
• every, "Every {minutes} min", with the Danish "Hvert {minutes}. min", the Swedish "Var {minutes} min" and the Norwegian "Hvert {minutes}. min".
• everyRange, "Every {from} to {to} min", with "Hvert {from}. til {to}. min", "Var {from} till {to} min" and "Hvert {from}. til {to}. min".

The fourth addition brought timetabledTime, "Timetabled {time}", with the Danish "Planlagt {time}", the Swedish "Ordinarie tid {time}" and the Norwegian "Rutetid {time}", the words departure boards in each language commonly give the timetabled time. It is named for what it says, beside StopTimeline's expectedTime, "Expected {time}", its sibling, since a trip's stops could strike a timetabled time too; it is one template filled by interpolate with the timetabled time, so each locale puts the word where its grammar does; and it is heard only, since the strike-through says it to the eye. Its JSDoc in en.ts says where it is heard. No new word marks the expected time: the "~" before an estimated one is the countdown's, said by the state's word (CR-4), and a time that is neither struck nor estimated needs none.

The interval is one template filled by interpolate, never words joined to the figures in code, as the contract's Words asks of a string that wraps figures, so each locale writes it in its own grammar. Two keys rather than one with an optional range, since a template's words are fixed and a range adds a word, "to", that one number has none of; their names and their {from} and {to} follow DisruptionCard's timeRange and betweenStops, and {minutes} names the minutes as DataStateKey's minutesDuration does, so the library has one name for a figure in minutes. The Danish and Norwegian write the ordinal their sentences write, "hvert 3. minut" and "hvert 3. minutt", the figure with its full stop, with the unit's abbreviation, as content design's "4 min" does; the Swedish ordinal, "var 3:e minut", takes an ending that changes with the figure, "2:a" and "3:e", which a template can't write, so the Swedish writes the figure bare, "var 3 min", as Swedish departure boards commonly write it. Each template carries its own unit, so minutesUnitLabel no longer reaches the interval; everyLabel and everyRangeLabel override it with the rest of the template.

For a caller using the pattern, with the reason. Each row is a rule: a must row's Don't is never right, a should row's needs a reason, and Checked by says what catches the Don't in a caller's code.