mapsize 1.1.0: nested treemap reaches deep folders

The map stopped nesting after a fixed 3 levels, so at / a chain like
mnt/raid/media used the whole budget on full-size wrappers and showed
empty boxes with only titles. Single-child directory chains now collapse
into one label, nesting depth is bounded by block size instead of a fixed
cap, and nested blocks show size and percentage of their parent.

internal/tui/nest_test.go

@@ -0,0 +1,72 @@
+package tui
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/charmbracelet/colorprofile"
+	"github.com/charmbracelet/x/ansi"
+
+	"github.com/andydixon/mapsize/internal/inventory"
+	"github.com/andydixon/mapsize/internal/scan"
+)
+
+func rootTree() *inventory.Tree {
+	t := inventory.New("/", inventory.KindDir)
+	add := func(p inventory.NodeID, name string, size int64) {
+		id := t.Add(p, name, inventory.KindFile)
+		n := t.Node(id)
+		n.Size, n.Alloc = size, size
+		n.Cat = inventory.CategoryFor(inventory.Ext(name), false, false)
+	}
+	dir := func(p inventory.NodeID, name string) inventory.NodeID {
+		id := t.Add(p, name, inventory.KindDir)
+		t.Node(id).Flags |= inventory.FlagScanned
+		return id
+	}
+	mnt := dir(0, "mnt")
+	raid := dir(mnt, "raid")
+	media := dir(raid, "media")
+	for _, show := range []string{"X-Files", "Simpsons", "Frasier"} {
+		s := dir(media, show)
+		for i := 1; i <= 5; i++ {
+			se := dir(s, fmt.Sprintf("S%02d", i))
+			for e := 1; e <= 20; e++ {
+				add(se, fmt.Sprintf("E%02d.mkv", e), int64(e)<<28)
+			}
+		}
+	}
+	usr := dir(0, "usr")
+	lib := dir(usr, "lib")
+	for i := range 50 {
+		add(lib, fmt.Sprintf("lib%d.so", i), int64(i+1)<<22)
+	}
+	v := dir(0, "var")
+	add(dir(v, "log"), "syslog", 2<<30)
+	t.Recompute()
+	t.Stats.Complete = true
+	return t
+}
+
+// A single-child chain (mnt → raid → media) must not use up the nesting
+// budget: the map at / should reach the seasons and their episodes.
+func TestNestingReachesDeepMedia(t *testing.T) {
+	tr := rootTree()
+	m := newModel(Options{Start: func(context.Context) (*scan.Scanner, *inventory.Tree, error) { return nil, tr, nil }}, nil, tr, func() {})
+	m.profile = colorprofile.TrueColor
+	send(m, size(160, 45))
+	if out := ansi.Strip(m.View().Content); !strings.Contains(out, "mnt/raid/media/") || !strings.Contains(out, "S01/") {
+		t.Fatalf("chain or seasons missing:\n%s", out)
+	}
+	files := 0
+	for _, nb := range m.tm.nested {
+		if nb.id >= 0 && !tr.Node(inventory.NodeID(nb.id)).IsDir() {
+			files++
+		}
+	}
+	if files < 50 {
+		t.Fatalf("only %d episode blocks drawn", files)
+	}
+}