mapsize/DEVELOPMENT.md

Development

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

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:

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

Benchmarks

make benchmark                          # Go micro-benchmarks (layout, render, filter, scan)
scripts/bench-scan.sh /path 1 2 4 8     # wall time and peak RSS per worker count
sudo DROP_CACHES=1 scripts/bench-scan.sh /path   # cold-cache runs
MAPSIZE_MEM_ROOT=/path go test ./internal/scan -run TestMemoryPerNode -v

Paste results into PERFORMANCE.md with the machine description. Never edit numbers by hand.

Terminal restoration checks

MAPSIZE_DEBUG_PANIC=ui bin/mapsize .        # panics on the first key press
MAPSIZE_DEBUG_PANIC=scanner bin/mapsize /   # panics in a scanner goroutine
stty -a                                     # echo/icanon must be back on

Profiling

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.