Initial patterm project

internal/app/tree_test.go

@@ -0,0 +1,41 @@
+package app
+
+import "testing"
+
+func TestVisibleSessionTreeScopesToFocusedRoot(t *testing.T) {
+	root1 := testChild("c1", "root1", "", StatusRunning)
+	child1 := testChild("c2", "child1", "c1", StatusRunning)
+	root2 := testChild("c3", "root2", "", StatusRunning)
+	child2 := testChild("c4", "child2", "c3", StatusRunning)
+
+	got := visibleSessionTree([]*Child{root1, child1, root2, child2}, "c4")
+	if len(got) != 2 || got[0].ID != "c3" || got[1].ID != "c4" {
+		t.Fatalf("visible tree = %v, want root2 + child2", childIDs(got))
+	}
+}
+
+func TestVisibleSessionTreeOmitsExited(t *testing.T) {
+	root := testChild("c1", "root", "", StatusRunning)
+	exitedRoot := testChild("c2", "dead-root", "", StatusExited)
+	runningChild := testChild("c3", "child", "c1", StatusRunning)
+	exitedChild := testChild("c4", "dead-child", "c1", StatusExited)
+
+	got := visibleSessionTree([]*Child{root, exitedRoot, runningChild, exitedChild}, "c1")
+	if len(got) != 2 || got[0].ID != "c1" || got[1].ID != "c3" {
+		t.Fatalf("visible tree = %v, want running root + running child", childIDs(got))
+	}
+}
+
+func testChild(id, name, parent string, status ChildStatus) *Child {
+	c := &Child{ID: id, Name: name, ParentID: parent}
+	c.status.Store(&status)
+	return c
+}
+
+func childIDs(cs []*Child) []string {
+	ids := make([]string, 0, len(cs))
+	for _, c := range cs {
+		ids = append(ids, c.ID)
+	}
+	return ids
+}