Second checkpoint

internal/service/category_test.go

@@ -0,0 +1,130 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"gis/internal/domain"
+
+	"github.com/google/uuid"
+)
+
+// stubCategoryRepo is an in-memory CategoryRepository for tests.
+type stubCategoryRepo struct {
+	store map[uuid.UUID]domain.Category
+}
+
+func newStubCategoryRepo() *stubCategoryRepo {
+	return &stubCategoryRepo{store: map[uuid.UUID]domain.Category{}}
+}
+
+func (r *stubCategoryRepo) Create(_ context.Context, c domain.Category) (domain.Category, error) {
+	if c.ID == uuid.Nil {
+		c.ID = uuid.New()
+	}
+	r.store[c.ID] = c
+	return c, nil
+}
+
+func (r *stubCategoryRepo) GetByID(_ context.Context, id uuid.UUID) (domain.Category, error) {
+	c, ok := r.store[id]
+	if !ok {
+		return domain.Category{}, domain.ErrNotFound
+	}
+	return c, nil
+}
+
+func (r *stubCategoryRepo) List(_ context.Context, _ *uuid.UUID) ([]domain.Category, error) {
+	return nil, nil
+}
+
+func (r *stubCategoryRepo) Update(_ context.Context, c domain.Category) (domain.Category, error) {
+	r.store[c.ID] = c
+	return c, nil
+}
+
+func (r *stubCategoryRepo) Delete(_ context.Context, id uuid.UUID) error {
+	delete(r.store, id)
+	return nil
+}
+
+func TestCategoryService_Create(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("root category succeeds", func(t *testing.T) {
+		svc := NewCategoryService(newStubCategoryRepo())
+		got, err := svc.Create(ctx, CategoryInput{Name: "root"})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if got.Name != "root" || got.ParentID != nil {
+			t.Fatalf("unexpected category: %+v", got)
+		}
+	})
+
+	t.Run("missing parent is a validation error", func(t *testing.T) {
+		svc := NewCategoryService(newStubCategoryRepo())
+		missing := uuid.New()
+		_, err := svc.Create(ctx, CategoryInput{Name: "child", ParentID: &missing})
+		if !errors.Is(err, domain.ErrValidation) {
+			t.Fatalf("want ErrValidation, got %v", err)
+		}
+	})
+
+	t.Run("existing parent succeeds", func(t *testing.T) {
+		repo := newStubCategoryRepo()
+		svc := NewCategoryService(repo)
+		root, _ := svc.Create(ctx, CategoryInput{Name: "root"})
+
+		child, err := svc.Create(ctx, CategoryInput{Name: "child", ParentID: &root.ID})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if child.ParentID == nil || *child.ParentID != root.ID {
+			t.Fatalf("child not linked to parent: %+v", child)
+		}
+	})
+}
+
+func TestCategoryService_Update_PreventsCycles(t *testing.T) {
+	ctx := context.Background()
+	repo := newStubCategoryRepo()
+	svc := NewCategoryService(repo)
+
+	root, _ := svc.Create(ctx, CategoryInput{Name: "root"})
+	child, _ := svc.Create(ctx, CategoryInput{Name: "child", ParentID: &root.ID})
+
+	t.Run("category cannot be its own parent", func(t *testing.T) {
+		_, err := svc.Update(ctx, root.ID, CategoryInput{Name: "root", ParentID: &root.ID})
+		if !errors.Is(err, domain.ErrValidation) {
+			t.Fatalf("want ErrValidation, got %v", err)
+		}
+	})
+
+	t.Run("category cannot descend from its own child", func(t *testing.T) {
+		_, err := svc.Update(ctx, root.ID, CategoryInput{Name: "root", ParentID: &child.ID})
+		if !errors.Is(err, domain.ErrValidation) {
+			t.Fatalf("want ErrValidation, got %v", err)
+		}
+	})
+
+	t.Run("valid reparent succeeds", func(t *testing.T) {
+		other, _ := svc.Create(ctx, CategoryInput{Name: "other"})
+		updated, err := svc.Update(ctx, child.ID, CategoryInput{Name: "child", ParentID: &other.ID})
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+		if updated.ParentID == nil || *updated.ParentID != other.ID {
+			t.Fatalf("reparent failed: %+v", updated)
+		}
+	})
+}
+
+func TestCategoryService_Update_MissingCategory(t *testing.T) {
+	svc := NewCategoryService(newStubCategoryRepo())
+	_, err := svc.Update(context.Background(), uuid.New(), CategoryInput{Name: "x"})
+	if !errors.Is(err, domain.ErrNotFound) {
+		t.Fatalf("want ErrNotFound, got %v", err)
+	}
+}