feat(weather): parse an Open-Meteo cache instead of OWM JSON

WMO codes to glyphs and words, moon phase, UV and AQI roles, and a
parser for the tab-separated cache the fetcher will write. Groundwork
for the Mirage-derived forecast cards.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

1 files changed, 161 insertions, 197 deletions

diff --git a/test/test_weather.lua b/test/test_weather.lua
index cdcdc2d..cea4645 100644
--- a/test/test_weather.lua
+++ b/test/test_weather.lua
@@ -1,236 +1,200 @@
 -- Checks for lib/weather.lua.
 -- Run from the repo root:  lua test/test_weather.lua
 -- The domain tables are what silently misreport when a boundary is off by one,
--- so every range boundary gets an assertion. The card itself is verified by
--- screenshot.
+-- so every range boundary gets an assertion. The cards themselves are verified
+-- by rendering them.
 
 package.path = './?.lua;' .. package.path
 local weather = require 'lib.weather'
 
--- === Condition id to icon =================================================
--- OWM ids group by hundreds, but the boundaries are not round numbers: the
--- ranges come from the polybar script that ran against this API for years.
--- Each assertion pairs the last id in a range with the first id of the next,
--- which is where an off-by-one would hide.
--- Sunrise 1500, sunset 1900, so DAY must sit INSIDE that window and NIGHT
--- outside it. Naming them without checking them against the window is how the
--- first draft of this test made every timestamp evaluate as night.
-local DAY, NIGHT = 1700, 2000
-
-local function icon(id, now)
-  return weather.icon(id, now, 1500, 1900)   -- sunrise 1500, sunset 1900
+local function slurp(path)
+  local f = assert(io.open(path, 'r'))
+  local s = f:read('*a')
+  f:close()
+  return s
 end
 
--- Thunderstorm: everything up to 232.
-assert(icon(200, DAY) == weather.ICON.thunder_day, 'id 200 day')
-assert(icon(232, DAY) == weather.ICON.thunder_day, 'id 232 is still thunder')
-assert(icon(232, NIGHT) == weather.ICON.thunder_night, 'id 232 night')
-
--- Light drizzle: 233..311.
-assert(icon(233, DAY) == weather.ICON.drizzle_day, 'id 233 leaves thunder')
-assert(icon(311, DAY) == weather.ICON.drizzle_day, 'id 311 is still light drizzle')
-
--- Heavy drizzle: 312..321.
-assert(icon(312, DAY) == weather.ICON.drizzle_heavy_day, 'id 312 is heavy drizzle')
-assert(icon(321, DAY) == weather.ICON.drizzle_heavy_day, 'id 321 is still heavy drizzle')
-
--- Rain: 322..531.
-assert(icon(322, DAY) == weather.ICON.rain_day, 'id 322 is rain')
-assert(icon(531, DAY) == weather.ICON.rain_day, 'id 531 is still rain')
-
--- Snow: 532..622. One icon, no day/night variant.
-assert(icon(600, DAY) == weather.ICON.snow, 'id 600 is snow')
-assert(icon(622, NIGHT) == weather.ICON.snow, 'snow is the same at night')
-
--- Fog: 623..771.
-assert(icon(741, DAY) == weather.ICON.fog, 'id 741 is fog')
-assert(icon(771, DAY) == weather.ICON.fog, 'id 771 is still fog')
-
--- Tornado is a single id, not a range.
-assert(icon(781, DAY) == weather.ICON.tornado, 'id 781 is tornado')
-
--- Clear and few clouds each have a day and a night face.
-assert(icon(800, DAY) == weather.ICON.clear_day, 'id 800 day is the sun')
-assert(icon(800, NIGHT) == weather.ICON.clear_night, 'id 800 night is the moon')
-assert(icon(801, DAY) == weather.ICON.few_day, 'id 801 day')
-assert(icon(801, NIGHT) == weather.ICON.few_night, 'id 801 night')
-
--- Overcast: 802..804, no night variant.
-assert(icon(804, DAY) == weather.ICON.overcast, 'id 804 is overcast')
-
--- Anything outside the known ids must be visibly wrong, not silently sunny.
-assert(icon(999, DAY) == weather.ICON.unknown, 'unknown id gets the error glyph')
-assert(weather.icon(nil, DAY, 1500, 1900) == weather.ICON.unknown, 'nil id')
-
--- Nothing may raise. A missing timestamp with a known sun, or a known
--- timestamp with no sun, both have to return a glyph rather than an error,
--- because an error here is a blank dashboard with no message.
-assert(weather.icon(800, nil, 1500, 1900) == weather.ICON.clear_day,
-  'a nil now must not raise, and falls back to the day face')
-assert(weather.icon(800, DAY, nil, nil) == weather.ICON.clear_day,
-  'no sun times must not raise')
-
--- The codepoint VALUES are deliberately not asserted. A test comparing
--- M.ICON.snow against a literal would only prove the same escape was typed
--- twice; whether E31A actually draws a snow cloud in the target font is not
--- something an assertion can see. That check is the glyph sheet rendered in
--- the plan's Step 5, and it is how a wrong-but-present codepoint was caught
--- before this file existed.
+-- === WMO code to glyph ====================================================
+-- Open-Meteo reports WMO weather codes. The groups are sparse (0-3, 45, 48,
+-- 51-57, ...), so each group's first and last code is asserted, plus a code
+-- in a gap, which must read as unknown rather than silently sunny.
+local I = weather.ICON
+assert(weather.icon(0, true) == I.clear_day, 'code 0 day is the sun')
+assert(weather.icon(0, false) == I.clear_night, 'code 0 night is the moon')
+assert(weather.icon(1, true) == I.few_day, 'code 1 is few clouds')
+assert(weather.icon(2, false) == I.few_night, 'code 2 night')
+assert(weather.icon(3, false) == I.overcast, 'code 3 is overcast, no night face')
+assert(weather.icon(45, true) == I.fog, 'code 45 is fog')
+assert(weather.icon(48, true) == I.fog, 'code 48 is fog')
+assert(weather.icon(51, true) == I.drizzle_day, 'code 51 is drizzle')
+assert(weather.icon(57, false) == I.drizzle_night, 'code 57 night')
+assert(weather.icon(61, true) == I.rain_day, 'code 61 is rain')
+assert(weather.icon(67, true) == I.rain_day, 'code 67 is still rain')
+assert(weather.icon(80, false) == I.rain_night, 'code 80 showers are rain')
+assert(weather.icon(82, true) == I.rain_day, 'code 82 is rain')
+assert(weather.icon(71, true) == I.snow, 'code 71 is snow')
+assert(weather.icon(77, false) == I.snow, 'code 77 is snow at night too')
+assert(weather.icon(85, true) == I.snow, 'code 85 snow showers')
+assert(weather.icon(86, true) == I.snow, 'code 86 snow showers')
+assert(weather.icon(95, true) == I.thunder_day, 'code 95 is thunder')
+assert(weather.icon(99, false) == I.thunder_night, 'code 99 night')
+
+-- Gaps and junk.
+assert(weather.icon(4, true) == I.unknown, 'code 4 is not a WMO code')
+assert(weather.icon(50, true) == I.unknown, 'code 50 sits in a gap')
+assert(weather.icon(-1, true) == I.unknown, 'negative code')
+assert(weather.icon(nil, true) == I.unknown, 'nil code')
+assert(weather.icon('3', true) == I.unknown, 'string code')
+
+-- An unknown day/night falls back to the day face, matching is_day().
+assert(weather.icon(0, nil) == I.clear_day, 'nil is_day draws the day face')
+
+-- The codepoint VALUES are deliberately not asserted. Whether a codepoint
+-- draws a snow cloud in the target font is not something an assertion can
+-- see; the glyph sheet in Task 3 is that check.
+
+-- === Descriptions =========================================================
+assert(weather.describe(0) == 'Clear sky', 'code 0 words')
+assert(weather.describe(63) == 'Rain', 'code 63 words')
+assert(weather.describe(99) == 'Thunderstorm, hail', 'code 99 words')
+assert(weather.describe(4) == 'Unknown', 'gap code words')
+assert(weather.describe(nil) == 'Unknown', 'nil code words')
+
+-- === Formatting ===========================================================
+assert(weather.deg(13.2) == '13\u{00B0}', 'rounds down')
+assert(weather.deg(13.5) == '14\u{00B0}', 'rounds half up')
+assert(weather.deg(-0.4) == '0\u{00B0}', 'just below zero reads 0')
+assert(weather.deg(-2.6) == '-3\u{00B0}', 'negative rounds away from zero')
+assert(weather.deg(nil) == '--', 'missing temperature is --, never 0')
+
+assert(weather.num(77) == '77', 'plain number')
+assert(weather.num(39.6, '%') == '40%', 'rounded with suffix')
+assert(weather.num(0, '%') == '0%', 'zero is a real reading')
+assert(weather.num(nil, '%') == '--', 'missing number is --')
+
+assert(weather.wind_unit('metric') == 'km/h', 'metric wind')
+assert(weather.wind_unit('imperial') == 'mph', 'imperial wind')
+assert(weather.wind_unit(nil) == 'km/h', 'unknown units default to metric')
+
+assert(weather.duration(37692) == '10h 28m', 'day length')
+assert(weather.duration(0) == '0h 00m', 'zero length')
+assert(weather.duration(-5) == '--', 'negative length is bad data')
+assert(weather.duration(nil) == '--', 'missing length')
+
+-- === Thresholds ===========================================================
+-- Each boundary and the value just under it.
+assert(weather.uv_role(2.9) == 'ok', 'UV under 3 is ok')
+assert(weather.uv_role(3) == 'warning', 'UV 3 is warning')
+assert(weather.uv_role(7.9) == 'warning', 'UV under 8 is warning')
+assert(weather.uv_role(8) == 'critical', 'UV 8 is critical')
+assert(weather.uv_role(nil) == nil, 'missing UV has no role')
+
+assert(weather.aqi_role(40) == 'ok', 'AQI 40 is ok')
+assert(weather.aqi_role(41) == 'warning', 'AQI 41 is warning')
+assert(weather.aqi_role(80) == 'warning', 'AQI 80 is warning')
+assert(weather.aqi_role(81) == 'critical', 'AQI 81 is critical')
+assert(weather.aqi_role(nil) == nil, 'missing AQI has no role')
+
+-- === Moon =================================================================
+-- Known 2024 phases (UTC): new 01-11 11:57, full 01-25 17:54, new 02-09 22:59.
+-- The mean synodic month drifts from the true one by up to about half a day,
+-- so the tolerance is one day of phase.
+local DAY_PHASE = 1 / 29.530588853
+local function circ(a, b) local d = math.abs(a - b) % 1; return math.min(d, 1 - d) end
+local p_new = weather.moon(1704974220)
+local p_full, lit_full = weather.moon(1706205240)
+local p_new2, lit_new2 = weather.moon(1707519540)
+assert(circ(p_new, 0) < DAY_PHASE, 'new moon phase near 0, got ' .. p_new)
+assert(circ(p_full, 0.5) < DAY_PHASE, 'full moon phase near 0.5, got ' .. p_full)
+assert(circ(p_new2, 0) < DAY_PHASE, 'next new moon near 0, got ' .. p_new2)
+assert(lit_full > 0.98, 'full moon is lit, got ' .. lit_full)
+assert(lit_new2 < 0.02, 'new moon is dark, got ' .. lit_new2)
+assert(weather.moon(nil) == nil, 'missing epoch')
+
+-- 28 glyphs from U+E38D. Phase 0 and phase 1 are both the new moon.
+assert(weather.moon_icon(0) == utf8.char(0xE38D), 'phase 0 is new moon')
+assert(weather.moon_icon(0.5) == utf8.char(0xE38D + 14), 'phase 0.5 is full moon')
+assert(weather.moon_icon(0.999) == utf8.char(0xE38D), 'phase near 1 wraps to new')
+assert(weather.moon_icon(nil) == I.unknown, 'missing phase')
 
 -- === Wind =================================================================
--- OWM metric gives m/s; the card shows km/h. The conversion is where a wrong
--- factor would look plausible but read 3.6x off.
-assert(weather.kmh(10) == 36, '10 m/s is 36 km/h')
-assert(weather.kmh(0) == 0, 'calm')
-assert(weather.kmh(nil) == nil, 'missing wind speed stays missing')
-
--- Beaufort thresholds, in km/h, from the polybar script. Each assertion sits
--- on a boundary and just past it, which is where an inclusive/exclusive
--- mistake hides.
-assert(weather.beaufort(0) == 0, 'calm is force 0')
-assert(weather.beaufort(1) == 0, '1 km/h is still force 0')
-assert(weather.beaufort(2) == 1, 'just over 1 is force 1')
-assert(weather.beaufort(5) == 1, '5 is still force 1')
-assert(weather.beaufort(6) == 2, 'just over 5 is force 2')
-assert(weather.beaufort(11) == 2, '11 is still force 2')
-assert(weather.beaufort(12) == 3, 'just over 11 is force 3')
-assert(weather.beaufort(19) == 3, '19 is still force 3')
-assert(weather.beaufort(28) == 4, '28 is force 4')
-assert(weather.beaufort(38) == 5, '38 is force 5')
-assert(weather.beaufort(49) == 6, '49 is force 6')
-assert(weather.beaufort(61) == 7, '61 is force 7')
-assert(weather.beaufort(74) == 8, '74 is force 8')
-assert(weather.beaufort(88) == 9, '88 is force 9')
-assert(weather.beaufort(102) == 10, '102 is force 10')
-assert(weather.beaufort(117) == 11, '117 is force 11')
-assert(weather.beaufort(118) == 12, 'over 117 is hurricane force')
-
 -- Compass: eight points, each spanning 45 degrees, offset by half a step so
--- north straddles 0 rather than starting at it. The wraparound is the case
--- that a naive floor(deg/45) gets wrong.
+-- north straddles 0 rather than starting at it.
 assert(weather.compass(0) == 'N', '0 is north')
 assert(weather.compass(360) == 'N', '360 wraps to north')
-assert(weather.compass(11) == 'N', 'just under the NE boundary')
+assert(weather.compass(22) == 'N', 'just under the NE boundary')
+assert(weather.compass(23) == 'NE', 'just over it')
 assert(weather.compass(349) == 'N', 'just over the NW boundary wraps to north')
-assert(weather.compass(45) == 'NE', '45 is northeast')
 assert(weather.compass(90) == 'E', '90 is east')
-assert(weather.compass(135) == 'SE', '135 is southeast')
 assert(weather.compass(180) == 'S', '180 is south')
-assert(weather.compass(225) == 'SW', '225 is southwest')
 assert(weather.compass(270) == 'W', '270 is west')
 assert(weather.compass(315) == 'NW', '315 is northwest')
 assert(weather.compass(nil) == nil, 'missing direction stays missing')
 
--- The arrow points where the wind is going, and OWM reports where it comes
--- from, so a north wind draws a downward arrow.
-assert(weather.arrow(0) == '\u{2193}', 'a north wind blows southward')
-assert(weather.arrow(180) == '\u{2191}', 'a south wind blows northward')
-assert(weather.arrow(nil) == '', 'no direction draws nothing')
-
 -- === Sun position =========================================================
--- t is the fraction of daylight elapsed, and the widget uses it to place the
--- dot along the arc. Sunrise 1000, sunset 2000, so midday is 1500.
+-- t is the fraction of daylight elapsed. Sunrise 1000, sunset 2000.
 assert(weather.sun_t(1000, 1000, 2000) == 0, 'at sunrise t is 0')
 assert(weather.sun_t(1500, 1000, 2000) == 0.5, 'at midday t is half')
 assert(weather.sun_t(2000, 1000, 2000) == 1, 'at sunset t is 1')
-
--- OWM reports today's sunrise and sunset, so between midnight and sunrise the
--- numerator is negative. The clamp is the whole handling; without it the dot
--- would be drawn off the left end of the arc.
 assert(weather.sun_t(500, 1000, 2000) == 0, 'before dawn clamps to 0')
 assert(weather.sun_t(9999, 1000, 2000) == 1, 'after dusk clamps to 1')
-
--- Degenerate input must not divide by zero.
 assert(weather.sun_t(1500, 2000, 2000) == 0, 'zero-length day gives 0, not nan')
 assert(weather.sun_t(nil, 1000, 2000) == nil, 'missing now gives nil')
-assert(weather.sun_t(1500, nil, 2000) == nil, 'missing sunrise gives nil')
 
--- is_day drives both the icon face and the dot's colour: a dot parked at the
--- end of the arc must not read as a sun that is still up.
 assert(weather.is_day(1500, 1000, 2000) == true, 'midday is day')
 assert(weather.is_day(1000, 1000, 2000) == true, 'sunrise counts as day')
-assert(weather.is_day(2000, 1000, 2000) == true, 'sunset counts as day')
 assert(weather.is_day(500, 1000, 2000) == false, 'before dawn is night')
-assert(weather.is_day(2500, 1000, 2000) == false, 'after dusk is night')
+assert(weather.is_day(nil, 1000, 2000) == true, 'unknown falls back to day')
 
 -- === Parsing the cache ====================================================
--- The parser reads scalars by key with Lua patterns rather than pulling in a
--- JSON library: the response is flat and known, and six numbers do not justify
--- a dependency. Caching the whole response still costs nothing, since a field
--- added later is already on disk.
-local function read(path)
-  local f = assert(io.open(path, 'r'))
-  local s = f:read('*a')
-  f:close()
-  return s
-end
-
-local w = weather.parse(read('test/fixtures/weather.json'))
-assert(w, 'the fixture must parse')
-assert(w.id == 501, 'condition id, got ' .. tostring(w.id))
-assert(w.description == 'moderate rain', 'description, got ' .. tostring(w.description))
-assert(w.temp == 18.34, 'temp, got ' .. tostring(w.temp))
-assert(w.feels_like == 18.11, 'feels like, got ' .. tostring(w.feels_like))
-assert(w.humidity == 72, 'humidity, got ' .. tostring(w.humidity))
-assert(w.wind_speed == 4.12, 'wind m/s, got ' .. tostring(w.wind_speed))
-assert(w.wind_deg == 230, 'wind direction, got ' .. tostring(w.wind_deg))
-assert(w.sunrise == 1789600000, 'sunrise, got ' .. tostring(w.sunrise))
-assert(w.sunset == 1789646000, 'sunset, got ' .. tostring(w.sunset))
-assert(w.city == 'Example City', 'city, got ' .. tostring(w.city))
-assert(w.dt == 1789625000, 'observation time, got ' .. tostring(w.dt))
-
--- temp comes before feels_like in the response and both live under "main",
--- so a lazy pattern would read one for the other. They differ in the fixture
--- precisely so this is checkable.
-assert(w.temp ~= w.feels_like, 'temp and feels_like must not collapse')
-
--- Failure modes all return nil rather than raising: a Lua error here is a
--- blank dashboard, not a message.
-assert(weather.parse(read('test/fixtures/weather_truncated.json')) == nil,
-  'a truncated response must give nil')
-assert(weather.parse('') == nil, 'empty input gives nil')
-assert(weather.parse('not json at all') == nil, 'garbage gives nil')
-assert(weather.parse(nil) == nil, 'nil input gives nil')
-
--- An error body carries cod 401 and no weather. It must not parse as data.
-assert(weather.parse('{"cod":401,"message":"Invalid API key."}') == nil,
-  'an API error body must give nil')
-
--- Negative temperatures are ordinary here for half the year, and a number in
--- exponent form must not be truncated at the 'e': reading 1.8e1 as 1.8 would
--- draw 2 degrees instead of 18, wrong in a way that still looks like weather.
-local cold = weather.parse(
-  '{"weather":[{"id":600,"description":"snow"}],"main":{"temp":-12.5},' ..
-  '"sys":{"sunrise":100,"sunset":200},"name":"X","dt":150}')
-assert(cold and cold.temp == -12.5, 'a negative temp, got ' .. tostring(cold and cold.temp))
-local exp = weather.parse(
-  '{"weather":[{"id":800}],"main":{"temp":1.8e1},' ..
-  '"sys":{"sunrise":100,"sunset":200}}')
-assert(exp and exp.temp == 18, 'exponent form, got ' .. tostring(exp and exp.temp))
+local w = weather.parse(slurp('test/fixtures/weather.txt'))
+assert(w, 'the fixture parses')
+assert(w.units == 'metric', 'units')
+assert(w.current.dt == 1792325700, 'current time')
+assert(w.current.temp == 13.2, 'current temperature')
+assert(w.current.feels == 11.5, 'feels like')
+assert(w.current.code == 3, 'current code')
+assert(w.current.is_day == true, 'is_day 1 is day')
+assert(w.current.humidity == 77, 'humidity')
+assert(w.current.wind == 10.2, 'wind')
+assert(w.current.wind_deg == 72, 'wind direction')
+assert(w.sun.rise == 1792301818 and w.sun.set == 1792339510, 'sun times')
+assert(w.air.aqi == 37, 'air quality')
+assert(#w.hours == 3, 'three hours, got ' .. #w.hours)
+assert(w.hours[1].uv == 1.15, 'first hour UV')
+assert(w.hours[2].uv == nil, 'null UV reads as nil')
+assert(w.hours[2].precip == 40, 'rain chance')
+assert(w.hours[3].temp == nil, 'null temperature reads as nil')
+assert(w.hours[3].is_day == false, 'is_day 0 is night')
+assert(#w.days == 2, 'two days')
+assert(w.days[1].min == 8.1 and w.days[1].max == 14.6, 'today min and max')
+assert(w.days[2].precip == 80, 'tomorrow rain chance')
+
+-- No air line: still parses, air is nil, the card shows --.
+local no_air = slurp('test/fixtures/weather.txt'):gsub('air\t37\n', '')
+local wa = weather.parse(no_air)
+assert(wa and wa.air == nil, 'missing air line is not fatal')
+
+-- Required records missing: nil, so the card draws its notice.
+assert(weather.parse((slurp('test/fixtures/weather.txt'):gsub('current\t[^\n]*\n', ''))) == nil,
+  'no current line is nil')
+assert(weather.parse((slurp('test/fixtures/weather.txt'):gsub('sun\t[^\n]*\n', ''))) == nil,
+  'no sun line is nil')
+assert(weather.parse((slurp('test/fixtures/weather.txt'):gsub('hour\t[^\n]*\n', ''))) == nil,
+  'no hour lines is nil')
+assert(weather.parse('') == nil, 'empty string')
+assert(weather.parse(nil) == nil, 'nil')
+assert(weather.parse('{"cod":401,"message":"bad"}') == nil, 'garbage')
 
 -- === Staleness ============================================================
--- 45 minutes is three missed fetches at the 15-minute interval, so one
--- transient failure does not flag the card.
-assert(weather.is_stale(1000, 1000) == false, 'a fresh reading is not stale')
-assert(weather.is_stale(1000, 1000 + 45 * 60) == false, 'exactly 45 min is the boundary')
-assert(weather.is_stale(1000, 1000 + 45 * 60 + 1) == true, 'past 45 min is stale')
-assert(weather.is_stale(nil, 1000) == true, 'no observation time counts as stale')
-
--- The age string is what the card prints beside the city, so it must be short.
-assert(weather.age_str(1000, 1000 + 90) == '1m', 'ninety seconds reads as 1m')
-assert(weather.age_str(1000, 1000 + 3600) == '1h', 'an hour reads as 1h')
-assert(weather.age_str(1000, 1000 + 7200) == '2h', 'two hours')
-assert(weather.age_str(1000, 1000 + 86400 * 2) == '2d', 'days, once it gets that bad')
-
--- Neither takes `now` on faith: a nil there used to raise, and a raise is a
--- blank dashboard rather than a message.
-assert(weather.is_stale(1000, nil) == true, 'a nil now must not raise')
-assert(weather.age_str(1000, nil) == '?', 'a nil now must not raise')
-
--- A dt in the future means a clock skew. "stale -17m" reads as a broken
--- widget, so the age floors at zero and the reading counts as fresh.
-assert(weather.age_str(2000, 1000) == '0m', 'a future dt reads as 0m, got ' ..
-  tostring(weather.age_str(2000, 1000)))
-assert(weather.is_stale(2000, 1000) == false, 'a future dt is not stale')
+-- Three missed fetches at the 15-minute interval.
+assert(weather.is_stale(1000, 1000 + 45 * 60) == false, 'exactly 45m is not stale')
+assert(weather.is_stale(1000, 1000 + 45 * 60 + 1) == true, 'over 45m is stale')
+assert(weather.is_stale(nil, 1000) == true, 'no timestamp is stale')
+assert(weather.age_str(1000, 1000 + 12 * 60) == '12m', 'minutes')
+assert(weather.age_str(1000, 1000 + 3 * 3600) == '3h', 'hours')
+assert(weather.age_str(1000, 1000 + 2 * 86400) == '2d', 'days')
+assert(weather.age_str(2000, 1000) == '0m', 'a future dt reads as 0m')
+assert(weather.age_str(nil, 1000) == '?', 'missing dt')
 
 print('test_weather: all assertions passed')