"""Tests for the deeper analysis: attenuation, fermentation curves, timings."""
from __future__ import annotations
from datetime import date
from pathlib import Path
import pytest
from brewing import (Run, attenuation_percent, days_to_target,
fermentation_curve, implausible_runs)
from conftest import seed_readings
def _doc(run_id="1", beer_type="Ale", sg="1045", date_="2026-01-01",
final="False", comment=""):
return {
"_id": f"id-{run_id}-{date_}-{sg}",
"beer_run_id": run_id,
"beer_type": beer_type,
"sg": sg,
"date": date_,
"final_reading": final,
"comment": comment,
}
# ------------------------------------------------------------ attenuation #
def test_attenuation_percent():
"""Attenuation is the fraction of the original gravity fermented away."""
# OG 1050, FG 1010: 40 of the 50 points above 1.000 went away.
run = Run.from_docs("1", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1010", date_="2026-01-20", final="True"),
])
assert attenuation_percent(run) == 80.0
def test_attenuation_percent_of_a_full_fermentation():
"""A wort that finishes at 1.000 has 100% attenuation."""
run = Run.from_docs("2", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1000", date_="2026-01-20", final="True"),
])
assert attenuation_percent(run) == 100.0
def test_attenuation_percent_needs_a_gravity_above_1000():
"""A run that started at or below 1.000 has no meaningful attenuation."""
run = Run.from_docs("3", [
_doc(sg="1000", date_="2026-01-01"),
_doc(sg="0995", date_="2026-01-20", final="True"),
])
assert attenuation_percent(run) is None
def test_attenuation_percent_of_an_unfinished_run_uses_its_current_gravity():
"""The current gravity stands in for the final one until the run ends."""
run = Run.from_docs("4", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1020", date_="2026-01-10"),
])
assert attenuation_percent(run) == 60.0
# ------------------------------------------------------- fermentation curve #
def test_fermentation_curve_is_empty_for_a_single_reading():
"""One reading is no curve."""
run = Run.from_docs("5", [_doc(sg="1045", date_="2026-01-01")])
assert fermentation_curve(run) == []
def test_fermentation_curve_progresses_from_zero_to_one():
"""The curve is the fraction of the gravity drop completed."""
run = Run.from_docs("6", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1030", date_="2026-01-10"),
_doc(sg="1010", date_="2026-01-20", final="True"),
])
curve = fermentation_curve(run)
assert len(curve) == 3
assert curve[0]["progress"] == 0.0
assert curve[1]["progress"] == 0.5
assert curve[2]["progress"] == 1.0
def test_fermentation_curve_carries_the_reading_details():
run = Run.from_docs("7", [
_doc(sg="1050", date_="2026-01-01", comment="brew day"),
_doc(sg="1010", date_="2026-01-20", final="True", comment="kegging"),
])
curve = fermentation_curve(run)
assert curve[0]["date"] == "2026-01-01"
assert curve[0]["sg_decimal"] == "1.050"
assert curve[0]["point_scale"] == "50"
assert curve[0]["comment"] == "brew day"
assert curve[1]["final"] is True
def test_fermentation_curve_is_empty_when_the_gravity_never_falls():
"""A run that only goes up has no drop to measure progress against."""
run = Run.from_docs("8", [
_doc(sg="1010", date_="2026-01-01"),
_doc(sg="1020", date_="2026-01-10", final="True"),
])
assert fermentation_curve(run) == []
# ------------------------------------------------------------- days to target #
def test_days_to_target():
"""How long the brew took to reach a given gravity."""
run = Run.from_docs("9", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1020", date_="2026-01-08"),
_doc(sg="1005", date_="2026-01-20", final="True"),
])
# 1020 is still above 1015, so the run does not reach 1015 until the
# third reading, 19 days in.
assert days_to_target(run, 1015) == 19
assert days_to_target(run, 1010) == 19
# 1020 is below 1025, so that target is reached on the second reading.
assert days_to_target(run, 1025) == 7
assert days_to_target(run, 1000) is None
def test_days_to_target_returns_none_when_never_reached():
run = Run.from_docs("10", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1040", date_="2026-01-20", final="True"),
])
assert days_to_target(run, 1010) is None
# ------------------------------------------------------------------- summary #
def test_run_summary_includes_the_new_analysis_fields():
from brewing import run_summary
run = Run.from_docs("11", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1010", date_="2026-01-20", final="True"),
])
summary = run_summary(run)
assert summary["attenuation"] == 80.0
assert len(summary["curve"]) == 2
assert summary["curve"][0]["progress"] == 0.0
def test_attenuation_is_none_for_a_final_gravity_below_water():
"""Beer cannot be less dense than water. Run 12 in the live data has a
final gravity of 900, which would otherwise show as 338% attenuation."""
run = Run.from_docs("12", [
_doc(sg="1042", date_="2025-10-05"),
_doc(sg="900", date_="2025-11-30", final="True"),
])
assert attenuation_percent(run) is None
def test_attenuation_is_none_when_it_would_exceed_100_percent():
run = Run.from_docs("13", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1000", date_="2026-01-20", final="True"),
])
# 1050 -> 1000 is exactly 100%, which is the limit but still valid.
assert attenuation_percent(run) == 100.0
run2 = Run.from_docs("14", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1010", date_="2026-01-20", final="True"),
])
assert attenuation_percent(run2) == 80.0
def test_implausible_runs_are_identified():
from brewing import implausible_runs
good = Run.from_docs("1", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1010", date_="2026-01-20", final="True"),
])
bad = Run.from_docs("12", [
_doc(sg="1042", date_="2025-10-05"),
_doc(sg="900", date_="2025-11-30", final="True"),
])
problems = implausible_runs([good, bad])
assert len(problems) == 1
assert problems[0]["beer_run_id"] == "12"
assert problems[0]["fg_points"] == 900
assert "below 1.000" in problems[0]["problem"]
def test_implausible_runs_ignores_good_runs():
from brewing import implausible_runs
good = Run.from_docs("1", [
_doc(sg="1050", date_="2026-01-01"),
_doc(sg="1010", date_="2026-01-20", final="True"),
])
assert implausible_runs([good]) == []
# ------------------------------------------------------- chart rendering #
def test_charts_do_not_reverse_the_gravity_axis():
"""Gravity must FALL on screen as the beer ferments.
The gravity charts originally set `reverse: true` on the y axis, which
puts the HIGH reading at the bottom of the plot - so the fermentation
curve climbed left to right and read as gravity *rising*. A brewer
reads a fermentation as a descending line, so the axis must not be
reversed. The point-scale run chart had the same bug.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
assert "reverse: true" not in charts_js, (
"a gravity chart is reversing the y axis; the fermentation curve "
"would climb instead of descend"
)
def test_attenuation_chart_truncates_long_names():
"""Long beer names were clipped at the left edge of the plot.
The rotated x-axis labels were cut off ("...x crying out loud"), so the
names are trimmed to a readable length before they are drawn. The
tooltip and the table below carry the full name.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
assert "name.length > 18" in charts_js, (
"the attenuation chart is not trimming long beer names"
)
# ------------------------------------------- suspect runs are not counted #
def _two_runs(repo):
"""One good brew and one with an impossible final gravity.
The bad run mimics the live data: run 12 has a final gravity of 900,
which is below water and makes the run look like a 56-day brew that
reached 18.64% alcohol.
"""
seed_readings(repo, [
("1", "Good ale", "1050", "2026-01-01", False, ""),
("1", "Good ale", "1010", "2026-01-10", True, ""),
# 56 days, and a final gravity below 1.000.
("12", "Bad brew", "1042", "2026-01-01", False, ""),
("12", "Bad brew", "0900", "2026-02-26", True, "typo"),
])
def _stat_values(body):
"""The figures in the analysis stat tiles, in order.
The tiles are rendered as label/value pairs, so the numbers can be
pulled out without depending on the exact markup.
"""
import re
values = re.findall(r'([^<]+)
', body)
return [v.strip() for v in values]
def test_a_suspect_run_is_excluded_from_the_brew_time_average(logged_in, repo):
"""The 56-day bad run must not drag the average brew time up.
This was the review finding: the run was excluded from the attenuation
average but not from the brew-time average, so one bad reading was
poisoning two different statistics.
"""
_two_runs(repo)
response = logged_in.get("/analysis")
assert response.status_code == 200
body = response.get_data(as_text=True)
values = _stat_values(body)
assert values, "the analysis page rendered no stat tiles"
# The stat tiles are: average attenuation, spread, average brew time,
# time to 1.010. The good run took 9 days; with the bad run folded
# in the average would be (9 + 56) / 2 = 32.5 days.
assert "9d" in values, f"expected a 9 day brew time, got {values}"
def test_a_suspect_run_is_excluded_from_the_time_to_1010_average(logged_in, repo):
"""Same for the "time to 1.010" figure."""
_two_runs(repo)
response = logged_in.get("/analysis")
body = response.get_data(as_text=True)
values = _stat_values(body)
assert values
# The good run reached 1.010 in 9 days; the bad one "reached" it in 56.
assert "9d" in values, f"expected 9 days to 1.010, got {values}"
def test_the_suspect_run_is_still_listed_for_review(logged_in, repo):
"""Excluding it from the averages must not hide it.
The run has to stay visible so it can be corrected.
"""
_two_runs(repo)
response = logged_in.get("/analysis")
body = response.get_data(as_text=True)
assert "Readings that need a second look" in body
assert "0.900" in body
def test_a_suspect_run_is_flagged_in_the_api(logged_in, repo):
"""The charts fetch /api/runs, so the flag has to be in the payload."""
_two_runs(repo)
response = logged_in.get("/api/runs")
assert response.status_code == 200
payload = response.get_json()
by_run = {str(r["beer_run_id"]): r for r in payload}
assert by_run["12"]["suspect"] is True
assert by_run["1"]["suspect"] is False
def test_a_suspect_run_is_not_the_strongest_brew_in_the_history(logged_in, repo):
"""The history page showed the bad run as the strongest beer.
An impossible final gravity produced an 18.64% ABV, which made run 12
the "strongest" brew in the history and pulled the average up.
The run's own row still shows its ABV - it is real data, and hiding it
would be worse - but it must not be counted as the strongest brew, and
it must not appear in the "Strongest" figure.
"""
_two_runs(repo)
response = logged_in.get("/history")
assert response.status_code == 200
body = response.get_data(as_text=True)
# The "Strongest" tile shows the good run's 4.76%, not the bad
# run's 18.64%. Find the Strongest tile and read its value.
import re
strongest = re.search(
r"Strongest.*?stat__value[^>]*>([^<]+)<", body, re.DOTALL
)
assert strongest, "the history page has no Strongest figure"
assert "18.64" not in strongest.group(1), (
f"the suspect run was counted as the strongest brew: {strongest.group(1)}"
)
def test_the_run_detail_api_also_flags_a_suspect_run(logged_in, repo):
"""The detail endpoint carries the same flag as the list endpoint.
A consumer of /api/runs/ must be able to tell an impossible
run from a good one.
"""
_two_runs(repo)
response = logged_in.get("/api/runs/12")
assert response.status_code == 200
assert response.get_json()["suspect"] is True
response = logged_in.get("/api/runs/1")
assert response.status_code == 200
assert response.get_json()["suspect"] is False
def test_the_charts_skip_suspect_runs():
"""The chart script must leave the suspect runs out.
A suspect run's fermentation curve plunges to a gravity below water,
which would drag the median line down and stretch the envelope.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
assert charts_js.count("!r.suspect") >= 2, (
"the charts must filter out the runs flagged as suspect"
)
# ------------------------------------------------- rising gravity #
def test_attenuation_is_none_when_the_gravity_went_up():
"""A negative attenuation is not a number a brewer can act on.
The guard rejected a final gravity below 1.000 and one implying more
than 100% attenuation, but a run whose gravity ROSE produced a
negative figure that was averaged into the headline number.
"""
run = Run.from_docs("30", [
_doc(sg="1010", date_="2026-01-01"),
_doc(sg="1020", date_="2026-01-20", final="True"),
])
assert attenuation_percent(run) is None
def test_a_rising_gravity_run_is_reported_as_implausible():
"""It must be listed for review, not just quietly dropped."""
run = Run.from_docs("31", [
_doc(sg="1010", date_="2026-01-01"),
_doc(sg="1020", date_="2026-01-20", final="True"),
])
problems = implausible_runs([run])
assert len(problems) == 1
assert problems[0]["beer_run_id"] == "31"
assert "went up" in problems[0]["problem"]
# ------------------------------------------------- undated readings #
def test_the_original_gravity_comes_from_the_first_dated_reading():
"""An undated reading cannot be placed on the timeline.
It used to sort to the front, so it became the OG - which put the OG
after the FG and produced a negative attenuation.
"""
run = Run.from_docs("32", [
_doc(sg="1050", date_="2026-01-01"),
{"_id": "x", "beer_run_id": "32", "beer_type": "Ale", "sg": "1005",
"date": None, "final_reading": "False", "comment": ""},
_doc(sg="1010", date_="2026-01-25", final="True"),
])
assert run.original_gravity() == 1050
assert run.final_gravity() == 1010
assert attenuation_percent(run) is not None
assert attenuation_percent(run) > 0
def test_days_to_target_skips_an_undated_reading():
"""One undated reading must not lose the whole figure.
The function gave up and returned None when the first reading at or
below the target had no date, even when a later reading did.
"""
run = Run.from_docs("33", [
_doc(sg="1050", date_="2026-01-01"),
{"_id": "y", "beer_run_id": "33", "beer_type": "Ale", "sg": "1005",
"date": None, "final_reading": "False", "comment": ""},
_doc(sg="1010", date_="2026-01-25", final="True"),
])
assert days_to_target(run, 1010) == 24
# ------------------------------------------------------- the charts #
def test_the_curve_chart_excludes_active_and_suspect_runs():
"""Only finished, plausible brews belong on the curve.
An active run's curve is a partial fermentation, and the curve is
meant to describe how a completed fermentation behaves.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
assert "!r.active" in charts_js, (
"the curve chart must leave the active runs out"
)
def test_the_curve_band_is_filled_to_the_max_not_the_median():
"""The shaded band has to span min to max.
With one dataset and `fill: "+1"` the band was filled to the NEXT
dataset - which was the median line, so the upper half of the range
was drawn as a hairline but never shaded, and the tooltip disagreed
with the shading.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
assert "envelopeMax" in charts_js, (
"the band needs a separate max dataset to fill down to"
)
assert 'label: "Range max"' in charts_js
def test_the_charts_fetch_the_run_payload_once():
"""/api/runs carries every reading of every run.
Four charts each fetched it independently, so the analysis page made
two identical round-trips of the whole collection.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
assert charts_js.count('fetch("/api/runs"') == 1, (
"the run payload should be fetched once and shared"
)
assert "function fetchRuns()" in charts_js
# ------------------------------------------------- the chart exclusions #
def test_the_abv_chart_leaves_out_the_suspect_runs():
"""A suspect run's ABV comes from an impossible reading.
Run 12 reads 18.64%, and plotting it stretched the y axis so every
real bar was squashed into the bottom of the plot - while the
"Strongest" tile on the same page correctly showed 8.53%. The chart
and the tile contradicted each other.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
abv_chart = charts_js.split("function drawAbvChart")[1]
abv_chart = abv_chart.split("function drawMonthsChart")[0]
assert "!r.suspect" in abv_chart, (
"the ABV chart must leave the suspect runs out"
)
def test_the_attenuation_chart_leaves_out_the_active_runs():
"""An active run's attenuation is measured against its CURRENT gravity.
A brew that has just started shows a 0% bar - which is the absence of
a result, not a result. The chart sits above the table of finished
brews.
"""
charts_js = (
Path(__file__).resolve().parents[1]
/ "src" / "flask" / "static" / "js" / "charts.js"
).read_text()
att_chart = charts_js.split("function drawAttenuationChart")[1]
att_chart = att_chart.split("function drawCurveChart")[0]
assert "!r.active" in att_chart, (
"the attenuation chart must leave the active runs out"
)
def test_a_suspect_active_run_is_still_listed_for_review(logged_in, repo):
"""A bad reading in an active run must not make the run vanish.
The API flags suspect runs over EVERY run, so the charts leave them
out. If the analysis page only looked at the finished ones, an
active run with a bad reading would disappear with no explanation
anywhere.
"""
seed_readings(repo, [
("1", "Finished ale", "1050", "2026-01-01", False, ""),
("1", "Finished ale", "1010", "2026-01-10", True, ""),
# An ACTIVE run whose latest reading is below water.
("20", "Active brew", "1042", "2026-02-01", False, ""),
("20", "Active brew", "0900", "2026-02-10", False, "typo"),
])
response = logged_in.get("/analysis")
body = response.get_data(as_text=True)
assert "Readings that need a second look" in body
assert "0.900" in body
def test_the_history_page_says_how_many_brews_the_abv_figure_is_from(logged_in, repo):
"""The tile must not quietly average fewer brews than it claims."""
seed_readings(repo, [
("1", "Good ale", "1050", "2026-01-01", False, ""),
("1", "Good ale", "1010", "2026-01-10", True, ""),
("12", "Bad brew", "1042", "2026-01-01", False, ""),
("12", "Bad brew", "0900", "2026-02-26", True, "typo"),
])
response = logged_in.get("/history")
body = response.get_data(as_text=True)
assert "across 1 of 2 finished brews" in body
def test_the_analysis_prose_counts_the_brews_that_contributed(logged_in, repo):
"""The prose must not claim more brews than actually contributed.
The prose is rendered from the attenuation figures, so it counts the
brews that produced one - not the brews that were merely counted.
"""
seed_readings(repo, [
("1", "Good ale", "1050", "2026-01-01", False, ""),
("1", "Good ale", "1010", "2026-01-10", True, ""),
("2", "Good pale", "1042", "2026-02-01", False, ""),
("2", "Good pale", "1012", "2026-02-10", True, ""),
("12", "Bad brew", "1042", "2026-01-01", False, ""),
("12", "Bad brew", "0900", "2026-02-26", True, "typo"),
])
response = logged_in.get("/analysis")
body = " ".join(response.get_data(as_text=True).split())
# Three finished brews, two of which contributed an attenuation.
assert "Across 2 of 3 finished brews" in body
def test_the_run_detail_api_carries_the_same_flags(logged_in, repo):
"""A consumer of the detail endpoint can tell an impossible run from a
good one, and an active run from a finished one."""
seed_readings(repo, [
("1", "Good ale", "1050", "2026-01-01", False, ""),
("1", "Good ale", "1010", "2026-01-10", True, ""),
("20", "Active brew", "1042", "2026-02-01", False, ""),
])
finished = logged_in.get("/api/runs/1").get_json()
assert finished["suspect"] is False
assert finished["active"] is False
active = logged_in.get("/api/runs/20").get_json()
assert active["suspect"] is False
assert active["active"] is True