add test suite

internal/tree/tree_test.go

@@ -0,0 +1,90 @@
+package tree
+
+import (
+	"testing"
+)
+
+func TestAddPath_single(t *testing.T) {
+	root := &Node{IsDir: true, Children: make(map[string]*Node)}
+	addPath(root, "README.md", false)
+	node, ok := root.Children["README.md"]
+	if !ok {
+		t.Fatal("missing README.md child")
+	}
+	if node.IsDir {
+		t.Error("README.md should not be a directory")
+	}
+}
+
+func TestAddPath_nested(t *testing.T) {
+	root := &Node{IsDir: true, Children: make(map[string]*Node)}
+	addPath(root, "cmd/main.go", false)
+	cmdNode, ok := root.Children["cmd"]
+	if !ok {
+		t.Fatal("missing cmd child")
+	}
+	if !cmdNode.IsDir {
+		t.Error("cmd should be a directory")
+	}
+	if _, ok := cmdNode.Children["main.go"]; !ok {
+		t.Fatal("missing main.go child under cmd")
+	}
+}
+
+func TestAddPath_overwrite_annotation(t *testing.T) {
+	root := &Node{IsDir: true, Children: make(map[string]*Node)}
+	node := addPath(root, "cmd", true)
+	node.Annotation = "ignored (default)"
+
+	node2 := addPath(root, "cmd", true)
+	if node2 != node {
+		t.Error("addPath should return the same node for repeated path")
+	}
+	if node2.Annotation != "ignored (default)" {
+		t.Errorf("annotation lost: %q", node2.Annotation)
+	}
+}
+
+func TestSplitPath(t *testing.T) {
+	tests := []struct {
+		name   string
+		input  string
+		expect []string
+	}{
+		{"root_file", "README.md", []string{"README.md"}},
+		{"two_parts", "cmd/main.go", []string{"cmd", "main.go"}},
+		{"three_parts", "internal/tree/node.go", []string{"internal", "tree", "node.go"}},
+		{"empty", "", nil},
+		{"only_slashes", "///", nil},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := splitPath(tt.input)
+			if len(got) != len(tt.expect) {
+				t.Errorf("splitPath(%q) = %v; want %v", tt.input, got, tt.expect)
+				return
+			}
+			for i := range got {
+				if got[i] != tt.expect[i] {
+					t.Errorf("splitPath(%q)[%d] = %q; want %q", tt.input, i, got[i], tt.expect[i])
+				}
+			}
+		})
+	}
+}
+
+func TestRenderBreadcrumb_root(t *testing.T) {
+	breadcrumb := RenderBreadcrumb("/home/user/project", "README.md")
+	expected := "project/README.md"
+	if breadcrumb != expected {
+		t.Errorf("RenderBreadcrumb(...) = %q; want %q", breadcrumb, expected)
+	}
+}
+
+func TestRenderBreadcrumb_nested(t *testing.T) {
+	breadcrumb := RenderBreadcrumb("/home/user/project", "internal/tree/tree.go")
+	expected := "project / internal / tree / tree.go"
+	if breadcrumb != expected {
+		t.Errorf("RenderBreadcrumb(...) = %q; want %q", breadcrumb, expected)
+	}
+}