Files
money/CLAUDE.md
T
nikolaandClaude Opus 5 c2eba53fd4 Add a rules screen that finds and removes dead rules
Nothing showed whether a rule was still earning its place. The new screen, on
5, lists every rule in file order with the number of transactions it claims,
marking those that claim none.

The count comes from Engine.Usage, which counts by first match, so a rule
shadowed by an earlier one reports zero even though its glob matches. That is
the case worth catching: such a rule looks correct in isolation and can never
fire.

d removes the selected rule and p removes every unused one, each behind a y/n
confirmation since this rewrites a hand-maintained file. config.DeleteRules
edits rules.toml textually rather than re-serialising the parsed rules, so
comments and layout survive; a comment directly above a rule goes with it,
while one separated by a blank line is left as a heading. The result is
re-parsed before it replaces the file.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-09 02:02:01 +02:00

124 lines
5.6 KiB
Markdown

# money
Statement-driven personal finance tracker. A data directory holds one folder per
account; statements dropped into those folders are parsed into a rebuildable
SQLite index, categorised by ordered glob rules, and browsed in a Bubble Tea TUI.
Read `README.md` first — it is the user-facing reference for every config key.
This file covers what the code assumes and why.
## Layout
```
cmd/money/main.go subcommands; the TUI is the default
internal/config rules.toml, account.toml, XDG config, data-root resolution
internal/model Account, Transaction, amount formatting, description normalisation
internal/glob the `*` / `?` matcher used by rules (linear time, no backtracking)
internal/parser Parser interface + registry; csv, cmd, nlb, revolut, traderepublic
internal/store SQLite index (modernc.org/sqlite, no cgo)
internal/importer directory walk, dedupe, balance checks
internal/rules applies ordered rules to rule_* columns only
internal/report per-tag aggregation, transfers excluded
internal/tui Bubble Tea models
```
## Invariants
**Rule verdicts and manual edits never share a column.** `rule_tag` /
`rule_transfer` are rewritten wholesale on every retag; `manual_tag` /
`manual_transfer` are only ever written by the user. Effective values are
`COALESCE(manual_*, rule_*)`. This is what makes `money retag` safe to run at
any time, and it is the first thing to preserve when touching the schema or the
rules engine. Covered by `TestManualTagSurvivesRetag`.
**Statements are the source of truth; the index is disposable.** Deleting
`.money/index.db` and re-importing must reproduce everything except manual tags
and manual transfer marks.
**Dedupe is by fingerprint**: `sha256(date | amount | normalised description |
ordinal)`, where the ordinal distinguishes identical lines *within one
statement*. Two identical purchases on one day both survive; the same line in an
overlapping statement does not duplicate. Unchanged files are skipped by
checksum before parsing at all — so an import with nothing new finishes in
milliseconds. That is the checksum skip working, not a failure.
**Money is `int64` minor units**, never a float. Per-account currency, no
conversion, and totals are never summed across currencies.
**First matching rule wins**, so transfer rules belong above general tag rules.
A rule setting several of `match` / `counterparty` / `type` requires all of them.
`config.AppendRule` therefore appends — never prepends — so saving from the
rule builder cannot shadow a rule the user wrote by hand.
**The rule builder is a form, so the global keymap must not apply there.**
`Update` routes to `updateRules` before `updateNormal` whenever the view is
`viewRules`, or typing `q` would quit and `i` would start an import. Any new
full-screen input needs the same treatment.
**A rule's usage count is how many transactions it wins, not how many its glob
could match** — `Engine.Usage` counts by `MatchIndex`, so a rule shadowed by an
earlier one correctly reports zero. That is what makes the rules screen able to
find dead rules at all.
**`config.DeleteRules` edits rules.toml textually, never by re-serialising the
parsed rules**, because comments and formatting are not recoverable from
`[]Rule`. A rule owns the comment lines directly above it; a comment separated
by a blank line is a heading for what follows and stays. Both writers go
through `writeFileAtomic`, and deletion re-parses the result before replacing
the file.
## Adding a bank parser
Implement `parser.Parser` and call `parser.Register` from an `init`. Nothing
else changes; the name becomes usable in an `account.toml`. Use
`parser.ParseAmount` rather than hand-rolling decimal handling — it copes with
`1.234,56`, trailing minus, parenthesised negatives, currency codes and both
the ASCII hyphen and U+2212.
Keep PDF text extraction separate from parsing: the bank parsers expose a pure
`parseXText(text string, digits int)` so they can be tested against captured
`pdftotext` output without a PDF fixture. `pdftotext -layout` (poppler-utils) is
a runtime dependency of `nlb` and `traderepublic`; no Go library reconstructs
column layout as well.
Do not hardcode absolute column positions from a sample PDF. `pdftotext`
compresses runs of spaces, so columns shift with font and page size — derive
positions from the header line (`traderepublic`) or from the line being parsed
(`nlb`).
## Verifying
```
go build ./... && go test ./... && go vet ./... && gofmt -l .
```
For end-to-end checks, build a throwaway data root under the scratchpad rather
than touching real data:
```
money --root /tmp/.../demo import
money --root /tmp/.../demo import # must report 0 new
money --root /tmp/.../demo ls --wide
```
### Driving the TUI in tests
Prefer feeding `tea.Msg` values to `Model.Update` directly — that is how every
existing TUI test works, and it covers the keymap without a terminal.
If a real terminal is genuinely needed, note that piping into `script` does not
deliver keystrokes. Use a pty and answer the two capability queries Bubble Tea
sends on startup, or the program blocks before its first render:
- `ESC]11;?` (background colour) → reply `ESC]11;rgb:1e1e/1e1e/1e1e ESC\`
- `ESC[6n` (cursor position) → reply `ESC[1;1R`
Also delete the index first, or the import you are trying to observe will be
skipped by checksum and finish instantly.
## Conventions
Comments explain why, not what. Errors name the file and the offending row or
key so a bad statement is actionable. Per-file import failures are reported and
the run continues; only a broken data root aborts.