1 files changed, 37 insertions, 0 deletions
diff --git a/test/test_data.lua b/test/test_data.lua
index 33551d1..e5b589f 100644
--- a/test/test_data.lua
+++ b/test/test_data.lua
@@ -54,4 +54,41 @@ local c2 = data.new_cpu_counter()
 c2:sample(1000, 900)
 assert(c2:sample(1000, 900) == nil, 'zero delta must give nil, not a division by zero')
 
+-- === Per-core CPU =========================================================
+-- The aggregate line answers "how busy is the machine"; the equaliser needs
+-- one entry per core. Both come from the same file, so they are parsed by the
+-- same rules and differ only in which lines they read.
+local percore = read('test/fixtures/proc_stat_percore')
+local cores = data.per_cpu_times(percore)
+assert(#cores == 4, 'one entry per cpuN line, got ' .. tostring(#cores))
+
+-- cpu0: 6441+24+3225+1056496+1932+0+760 = 1068878 total, idle+iowait = 1058428
+assert(cores[1].total == 1068878, 'core 0 total, got ' .. tostring(cores[1].total))
+assert(cores[1].idle == 1058428, 'core 0 idle, got ' .. tostring(cores[1].idle))
+
+-- Ordering matters: bar N must be core N, so the list follows the file.
+assert(cores[2].total == 1066406, 'core 1 total, got ' .. tostring(cores[2].total))
+
+-- The aggregate 'cpu ' line must NOT be counted as a core: it would draw a
+-- seventeenth bar showing the average, which looks like a real core.
+for i, c in ipairs(cores) do
+  assert(c.total < 2000000, 'entry ' .. i .. ' looks like the aggregate line')
+end
+
+-- A counter per core is just another instance, which is why new_cpu_counter
+-- holds its own previous sample rather than using a module-level one.
+local c0 = data.new_cpu_counter()
+assert(c0:sample(cores[1].total, cores[1].idle) == nil, 'first sample is nil')
+local busy = c0:sample(cores[1].total + 100, cores[1].idle + 25)
+assert(busy == 75.0, 'second sample 75%, got ' .. tostring(busy))
+
+-- Malformed input yields an empty list, never an error: a raise here is a
+-- blank dashboard.
+assert(#data.per_cpu_times('') == 0, 'empty input gives an empty list')
+assert(#data.per_cpu_times('garbage\nlines\n') == 0, 'garbage gives an empty list')
+assert(#data.per_cpu_times(nil) == 0, 'nil gives an empty list')
+-- A truncated line (fewer than the 5 fields the maths needs) is skipped
+-- rather than producing a nonsense total.
+assert(#data.per_cpu_times('cpu0 1 2\n') == 0, 'a short line is skipped')
+
 print('test_data: all assertions passed')