diff options
| -rw-r--r-- | lib/weather.lua | 17 | ||||
| -rw-r--r-- | test/test_weather.lua | 14 |
2 files changed, 31 insertions, 0 deletions
diff --git a/lib/weather.lua b/lib/weather.lua index d36bcf5..b1fda4d 100644 --- a/lib/weather.lua +++ b/lib/weather.lua @@ -186,4 +186,21 @@ function M.parse(src) return w end +-- Three missed fetches at the 15-minute interval. +M.STALE_AFTER = 45 * 60 + +function M.is_stale(dt, now) + if type(dt) ~= 'number' then return true end + return (now - dt) > M.STALE_AFTER +end + +-- Short age for the marker beside the city: "12m", "3h", "2d". +function M.age_str(dt, now) + if type(dt) ~= 'number' then return '?' end + local s = now - dt + if s < 3600 then return math.floor(s / 60) .. 'm' end + if s < 86400 then return math.floor(s / 3600) .. 'h' end + return math.floor(s / 86400) .. 'd' +end + return M diff --git a/test/test_weather.lua b/test/test_weather.lua index 739161b..95908ce 100644 --- a/test/test_weather.lua +++ b/test/test_weather.lua @@ -208,4 +208,18 @@ local exp = weather.parse( '"sys":{"sunrise":100,"sunset":200}}') assert(exp and exp.temp == 18, 'exponent form, got ' .. tostring(exp and exp.temp)) +-- === 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') + print('test_weather: all assertions passed') |