The one check that is load-bearing rather than tidy: a recurrence interval
below 1, or a fractional one, is REFUSED rather than clamped. The projection
walk terminates only if every step strictly advances, and a clamped zero would
hand the owner a schedule their file does not describe — silently.
Purchase.source is checked too: the cost it names must exist, and the
occurrence date must parse. PURCHASE_DATE already accepts both YYYY-MM and
YYYY-MM-DD, which is exactly the range a slot date can take.
`Settings.digits` replaces `CurrencyDef.digits`. Every amount rounds to it,
whatever its currency, and `digitsFor` is gone: the sixteen call sites read the
setting, and the domain functions that took a currency table purely to look
digits up take a `digits: number` instead. Schema 6.
The owner asked for this with the cost in front of them, and the cost is real:
a dataset mixing minor units cannot be described any more. Yen at 0 beside
kroner at 2 has no correct global value — 2 gives ¥1234.56, an amount yen
cannot represent; 0 rounds 49.95 DKK to 50 and drifts the carry from the bank.
Nothing in the app warns. docs/specs/2026-09-02-global-decimals-design.md
argues it in full, including what re-adding a per-currency override would take,
and AGENTS.md §1 now says not to reintroduce one without revisiting the
decision.
The 5 -> 6 step takes the MAXIMUM of the per-currency digits, not the base
currency's. A dataset holding a three-decimal currency already has
three-decimal amounts in it, and adopting the base's 2 would truncate the next
edit of one; the maximum can only keep more precision, never less. On every
dataset this app has written all four currencies record 2, so nothing rounds
differently than before.
Changing the setting does not rewrite stored amounts. 49.95 stays 49.95 and
shows as 50; totals recompute at the new precision. Rewriting each Money is a
destructive whole-dataset write, which §1 owes a backup export first, and it is
lossy one way.
Display turned out to be the hole in the plan. src/ui/format.ts pinned
minimumFractionDigits: 2 in a module-level Intl.NumberFormat, so it never read
the dataset at all — equally broken under per-currency digits, where a JPY
rendered "3,333.00", so a pre-existing gap rather than a regression. Shipping a
Settings control that display ignores would look broken at 0 and be lossy at 3,
hiding precision the dataset holds. So format.ts takes digits like roundMoney
does, useMoneyFormat() binds them for the 64 call sites, and postRowCells takes
the formatter as an argument because it is a plain helper, not a component.
currencyDigits.test.ts is rewritten rather than deleted. Driving a dataset at
ZERO decimals through rounding, both FX directions, both split modes, plan
division, the fold and the month view still tells a real implementation from
one assuming 2 — it just cannot prove per-currency flow, because there is none.
It also asserts that raising the setting to 2 changes what the fold produces.
Verified in Chrome, not only in tests: a v5 dataset with digits 2/0/3 written
straight into IndexedDB migrates to a setting of 3, the table loses its
Decimals column, and editing the control persists schema 6 with digits stripped
from each currency and income left at 20000.55. The same month reads 600/206 at
zero decimals and 600.000/205.561 at three, so the figures recompute rather
than merely reformat.
Not verified here: the .ods in a real spreadsheet.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
GBP joins the currencies the app comes with: £, two decimals, and a
committed fallback rate of 8.704735 DKK to the pound. build.ts now
fetches it too, so a build with a network bakes a live GBP rate and one
without still covers it — the coverage check derives from the seed table,
so it demanded GBP as soon as the table listed it.
The seed table alone would not have delivered this. Baked currencies and
rates seed a NEW dataset and nothing else, so an existing dataset would
have been left typing the code, name, symbol and decimals by hand. A
4 -> 5 migration adds sterling to a dataset that lacks it, with its rate.
Supplying a rate is the one thing the "rates never backstop a cleared
rate" rule permits here: it forbids re-supplying a number the owner
deleted, not introducing one for a currency they have never had. A GBP
the owner already defined, or a GBP rate they already hold, is left
exactly as it is — asserted, including the case where their definition is
"wrong" (zero decimals), because it is theirs.
This exposed a real latent bug. The 2 -> 3 step seeded the live
seed-currency table BY REFERENCE, so adding sterling there would have
retroactively changed what an old dataset received from a step it had
already been through — silently, and only for whoever had not migrated
yet. Every step now carries its own frozen copy, and a source-level guard
fails the build if a live default is imported again. Scoping that guard
took two goes: matching the whole file flagged the comment explaining the
rule, and then flagged the frozen local copy that is the fix.
Two test fixtures used GBP as their example of an UNSUPPORTED currency
and now use CHF, which no seed table lists.
Verified in a browser by writing a schemaVersion 4 dataset into IndexedDB
and reloading: the currency table gains "British pound / £ / 2" with
"manual · 2026-09-02", the post currency selector offers GBP, and the
income and post survive untouched. Note for the next person — a migration
applies in memory on load and is written back on the next mutation, so
reading IndexedDB straight after a reload still shows the OLD version.
That is recorded in docs/TODO.md, because it made this verification look
like a failure at first.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Two requests. The second is small; the first changed the money layer.
TYPING THE CURRENCY. The purchase total field now reads "30$" as thirty
dollars, "€25,50" as EUR 25.50, "250 kr" as DKK, "1.234,56 usd" as USD
1234.56, and sets the currency selector from what was typed. Entry speed is a
stated product feature and a second control per amount works against it.
The field is type="text", not type="number": a number input silently discards
anything non-numeric, so "30$" would never reach the parser. It keeps its own
text so a half-typed "30." stays as typed and only commits when it parses.
Separator handling is where parseMoneyInput earns its 26 tests. With both "."
and "," present the LAST is the decimal point, which covers "1.234,56" and
"1,234.56" without knowing a locale. With one, it groups thousands if exactly
three digits follow and is a decimal point otherwise — so "1,500" is fifteen
hundred and "1,5" is one and a half. Spaces group thousands only in
three-digit groups, because "30 40" is two amounts typed by mistake and
committing it as 3040 would be worse than rejecting it. An unrecognised
currency returns null rather than falling back: reading "30 GBP" as 30 DKK
would book money at the wrong currency.
USER-DEFINED CURRENCIES. `Currency` was a closed union and decimal places were
a module constant, so "add a currency" was a code change. Both now live in the
dataset: `Dataset.currencies` is the authority on which codes are valid, what
they are called, their symbol, and how many decimals they round to. Settings
grows a table to add, edit and remove them.
That forced the money layer open. `roundMoney` takes a DIGIT COUNT, not a
currency code, and every one of its ~29 call sites resolves digits from the
dataset via `digitsFor`. Making digits a required number rather than an
optional one with a default of 2 is the whole safety argument: every site
became a compile error the type checker enumerated for me, where a default
would have left each one silently correct for DKK/USD/EUR and silently wrong
for the first zero-decimal currency the owner adds.
Because every existing currency uses two decimals, a broken version of this
refactor would still pass all 356 previous tests. src/domain/currencyDigits.test.ts
is the oracle that cannot lie: a JPY-style zero-decimal currency driven through
roundMoney, both FX directions, both split modes, finance-plan division, the
fold, and the month view, asserting no figure has a fractional yen in it.
Guards that come with it, all tested:
- Codes are identity — they key the FX table and every stored Money — so they
are normalised (" jpy " -> "JPY") and cannot be edited, only added/removed.
- A currency in use cannot be removed, and the refusal names what refers to
it. The same reasoning as posts being archived rather than deleted: stored
Money carries the code, and dangling references would make the import
validator refuse the owner's own exported file. Removing an unused one takes
its exchange rate with it, leaving no orphan row.
- The import validator now checks the currency table itself — codes, duplicate
codes, integer decimals 0-4 — and validates every Money against it. That
boundary check replaces the compile-time safety the closed union provided.
- parseFxResponse takes the accepted codes instead of a global constant, so a
rate service returning dozens cannot put unreachable rows in the table.
Migration v2 -> v3 seeds the currency table. Behaviour-preserving by
construction: every currency that existed had two decimal places and the
seeded table records two, so not one stored amount can round differently than
it did before. An existing `currencies` field is kept rather than overwritten,
since a hand-edited file could already carry currencies the owner added.
Verified in the browser, not just in tests: JPY added through the real Settings
form with 0 decimals, and the five inputs above typed into the real purchase
field, each setting the right currency.
Two obsolete test helpers went away. plans.test.ts and actions.test.ts used to
monkey-patch the CURRENCY_DIGITS constant to prove the table was consulted;
digits are an argument now, so those tests just ask for zero decimals.
types.test.ts no longer asserts "the supported currencies are exactly DKK,
USD, EUR" — that stopped being a property of the code.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
monthView folds from the start of the dataset, so it costs O(months) per
call. The summary sheet and every per-post sheet each called it once per
(post, month), making a full export O(posts x months^2). buildWorkbook now
takes one pass, indexes the figures by post, and hands that to the sheets.
TODO called this "fine at personal-budget scale". Measured against the old
code it is not, once history accumulates: 30 posts over 10 years went from
7983 ms to 135 ms (59x), and that work is synchronous on the main thread, so
it was a visible freeze on clicking Export. 10 posts x 2 years: 44 ms -> 2.5 ms.
content.xml is byte-for-byte identical on a fixture exercising every sheet
(versioned rules, an override, an archived post, a percent split, a fixed
split and a finance plan).
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Rejects a missing rules array, a malformed or out-of-range start month, and two
versions sharing a month — which would make the effective rule ambiguous — at
the import boundary rather than letting the fold resolve something arbitrary.
Also rejects a rule of an unknown kind and a fixed rule in an unsupported
currency. The first falls through resolveRule's percentage branch and turns
every figure after it into NaN; the second throws MissingRateError deep inside
the balance fold. Both are the failure class this validation exists to stop.
The rule's VALUE stays unvalidated: over-budget is always allowed.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Post.standingRule becomes Post.rules: RuleVersion[], resolved by ruleAt() as
the last version effective at or before a month. Per-month overrides still win
outright; a post with no applicable version allocates zero rather than
applying its earliest rule backwards.
allocationFor keeps its signature, so the fold, the views and the ODS export
are untouched. Settings gets a read-only rule summary for now; the history
editor follows.
Implements docs/superpowers/specs/2026-09-02-fast-entry-refinements-design.md.
Three changes shipped together because they share one tab order.
Bulk rows are description -> amount -> note, and nothing else is a tab stop.
The list always ends in exactly one blank row, appended as soon as the last
row is filled, so Tab flows into a new line with no special case and new rows
appear on touch too. The Add-line button is gone; the per-row remove button is
now a hover/focus x with tabIndex={-1}, and Backspace in an empty description
removes the row and lands on the previous row's note.
Purchases no longer demand a day. `date` accepts "2026-09" as well as
"2026-09-14"; entry defaults to the month, with an opt-in "set exact date"
link. No migration: monthOf() already parsed both shapes, verified before
choosing this over splitting the field into month + optional day, which would
have meant a schema migration in the browser against the user's only copy of
their data for an identical outcome.
Notes are an optional field on Purchase, in both entry forms and shown beside
the description in the month lists. Empty notes are omitted rather than stored
as "", so absent stays absent.
Also closes a pre-existing gap the spec surfaced: the JSON importer never
validated purchase.date, so a malformed date passed import and threw later
inside the balance fold. It is now rejected at the boundary, with out-of-range
months and days covered.
A row holding only a note is deliberately NOT blank: it asks for the missing
description and amount rather than being silently discarded.
Keyboard behaviour - tab traversal, Backspace-to-remove, focus after append -
cannot be verified in this environment and needs confirming in a browser.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Generated in-browser with fflate, so export works offline. mimetype is
stored first and uncompressed as the ODS spec requires.
Also adds datasetMonthSpan to the domain views layer, which determines
the month range an export should cover: from the fold start through
the latest month touched by any month record or purchase slice,
including future finance-plan slices.
Widened the mimetype-header test's byte slice from 64 to 96 bytes: the
zip local-file header for "mimetype" is 38 bytes and ODS_MIMETYPE is
46 characters, so 64 bytes could never contain the full string
regardless of implementation.
Numeric cells carry office:value so the export can be summed and pivoted
in a spreadsheet rather than arriving as text.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Import validates far enough that the fold cannot throw on imported data:
exactly one remainder-absorbing split per purchase, at least one split,
every split.postId resolving to a real post, every currency supported,
and every MonthId well-formed and in range (01-12). Over-budget and
percentages not summing to 100 remain permitted.
Tightens MONTH_ID to /^\d{4}-(0[1-9]|1[0-2])$/ (shape-only regex would
let "2026-13" through import and silently misfile inside the balance
fold, mirroring the defect already fixed in src/domain/months.ts).
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Lucas Winther