# Development

Requires Go (see `go.mod`). No CGO, no external tools.

```sh
make build      # bin/mapsize, bin/treegen
make test       # go test ./...
make race       # go test -race ./...
make vet fmt-check
make benchmark  # go test -bench
make fuzz       # short fuzz runs of snapshot / treemap / filter
make release    # cross-compiled binaries in bin/release
```

## Test data

`treegen` creates synthetic trees:

```sh
bin/treegen --out /tmp/t --directories 50000 --files 1000000 --max-depth 20 --sparse --unicode
bin/mapsize /tmp/t
```

## Profiling

```sh
bin/mapsize --no-ui --cpuprofile cpu.prof --memprofile mem.prof /path
go tool pprof -http=: cpu.prof
```

`--log FILE --log-level debug` writes a log without disturbing the TUI.
Paths are logged only at `debug`/`trace` level.

## Layout

See ARCHITECTURE.md. Rules of thumb:

* `internal/treemap` and `internal/filter` must not import UI packages.
* Only `internal/platform` may contain OS-specific code (build tags).
* All strings derived from filenames go through `textutil.Sanitize` before
  reaching a terminal.