Files
money/CLAUDE.md
T
nikolaandClaude Opus 5 3ba26cadae Document the invariants and testing recipes in CLAUDE.md
Records what the code assumes rather than what it does: why rule verdicts and
manual edits live in separate columns, how the dedupe fingerprint works, why
column positions must not be hardcoded from a sample PDF, and the pty
handshake needed to drive the TUI in a real terminal.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-09 01:20:27 +02:00

4.5 KiB

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.

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.