Implement TaskUpdateParams builder

- TaskUpdateParams struct with fluent setter methods
- NewTaskUpdate() constructor
- Setters: SetTitle, SetDescription, SetColor, SetOwner, SetCategory,
  SetPriority, SetScore, SetDueDate, SetStartDate, SetReference, SetTags
- Clear methods: ClearDueDate, ClearStartDate, ClearOwner, ClearCategory
- Only set fields are included in update request (partial updates)
- Client.UpdateTaskFromParams for fluent task updates
- Comprehensive test coverage

task_update_params_test.go

@@ -0,0 +1,271 @@
+package kanboard
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestNewTaskUpdate(t *testing.T) {
+	params := NewTaskUpdate()
+
+	if params == nil {
+		t.Fatal("expected non-nil TaskUpdateParams")
+	}
+	if params.title != nil {
+		t.Error("expected title to be nil")
+	}
+}
+
+func TestTaskUpdateParams_Chaining(t *testing.T) {
+	dueDate := time.Date(2025, 12, 31, 0, 0, 0, 0, time.UTC)
+
+	params := NewTaskUpdate().
+		SetTitle("Updated Title").
+		SetDescription("New description").
+		SetColor("red").
+		SetOwner(10).
+		SetCategory(5).
+		SetPriority(2).
+		SetDueDate(dueDate).
+		SetReference("JIRA-456").
+		SetTags("urgent", "review")
+
+	if *params.title != "Updated Title" {
+		t.Errorf("expected title='Updated Title', got %s", *params.title)
+	}
+	if *params.description != "New description" {
+		t.Errorf("expected description='New description', got %s", *params.description)
+	}
+	if *params.colorID != "red" {
+		t.Errorf("expected colorID='red', got %s", *params.colorID)
+	}
+	if *params.ownerID != 10 {
+		t.Errorf("expected ownerID=10, got %d", *params.ownerID)
+	}
+	if *params.categoryID != 5 {
+		t.Errorf("expected categoryID=5, got %d", *params.categoryID)
+	}
+	if *params.priority != 2 {
+		t.Errorf("expected priority=2, got %d", *params.priority)
+	}
+	if *params.dueDate != dueDate.Unix() {
+		t.Errorf("expected dueDate=%d, got %d", dueDate.Unix(), *params.dueDate)
+	}
+	if *params.reference != "JIRA-456" {
+		t.Errorf("expected reference='JIRA-456', got %s", *params.reference)
+	}
+	if len(params.tags) != 2 || params.tags[0] != "urgent" {
+		t.Errorf("expected tags=['urgent', 'review'], got %v", params.tags)
+	}
+}
+
+func TestTaskUpdateParams_SetScore(t *testing.T) {
+	params := NewTaskUpdate().SetScore(5)
+
+	if *params.score != 5 {
+		t.Errorf("expected score=5, got %d", *params.score)
+	}
+}
+
+func TestTaskUpdateParams_SetStartDate(t *testing.T) {
+	startDate := time.Date(2025, 6, 15, 0, 0, 0, 0, time.UTC)
+	params := NewTaskUpdate().SetStartDate(startDate)
+
+	if *params.startDate != startDate.Unix() {
+		t.Errorf("expected startDate=%d, got %d", startDate.Unix(), *params.startDate)
+	}
+}
+
+func TestTaskUpdateParams_ClearDueDate(t *testing.T) {
+	params := NewTaskUpdate().ClearDueDate()
+
+	if params.dueDate == nil {
+		t.Fatal("expected dueDate to be set")
+	}
+	if *params.dueDate != 0 {
+		t.Errorf("expected dueDate=0, got %d", *params.dueDate)
+	}
+}
+
+func TestTaskUpdateParams_ClearStartDate(t *testing.T) {
+	params := NewTaskUpdate().ClearStartDate()
+
+	if *params.startDate != 0 {
+		t.Errorf("expected startDate=0, got %d", *params.startDate)
+	}
+}
+
+func TestTaskUpdateParams_ClearOwner(t *testing.T) {
+	params := NewTaskUpdate().ClearOwner()
+
+	if *params.ownerID != 0 {
+		t.Errorf("expected ownerID=0, got %d", *params.ownerID)
+	}
+}
+
+func TestTaskUpdateParams_ClearCategory(t *testing.T) {
+	params := NewTaskUpdate().ClearCategory()
+
+	if *params.categoryID != 0 {
+		t.Errorf("expected categoryID=0, got %d", *params.categoryID)
+	}
+}
+
+func TestTaskUpdateParams_toUpdateTaskRequest(t *testing.T) {
+	dueDate := time.Date(2025, 12, 31, 0, 0, 0, 0, time.UTC)
+
+	params := NewTaskUpdate().
+		SetTitle("Updated Title").
+		SetDescription("Details").
+		SetPriority(2).
+		SetDueDate(dueDate).
+		SetTags("urgent")
+
+	req := params.toUpdateTaskRequest(42)
+
+	if req.ID != 42 {
+		t.Errorf("expected ID=42, got %d", req.ID)
+	}
+	if *req.Title != "Updated Title" {
+		t.Errorf("expected Title='Updated Title', got %s", *req.Title)
+	}
+	if *req.Description != "Details" {
+		t.Errorf("expected Description='Details', got %s", *req.Description)
+	}
+	if *req.Priority != 2 {
+		t.Errorf("expected Priority=2, got %d", *req.Priority)
+	}
+	if *req.DateDue != dueDate.Unix() {
+		t.Errorf("expected DateDue=%d, got %d", dueDate.Unix(), *req.DateDue)
+	}
+	if len(req.Tags) != 1 || req.Tags[0] != "urgent" {
+		t.Errorf("expected Tags=['urgent'], got %v", req.Tags)
+	}
+}
+
+func TestTaskUpdateParams_toUpdateTaskRequest_PartialUpdate(t *testing.T) {
+	// Only set title, nothing else
+	params := NewTaskUpdate().SetTitle("New Title")
+
+	req := params.toUpdateTaskRequest(42)
+
+	if *req.Title != "New Title" {
+		t.Errorf("expected Title='New Title', got %s", *req.Title)
+	}
+	// Unset fields should be nil
+	if req.Description != nil {
+		t.Error("expected Description to be nil")
+	}
+	if req.Priority != nil {
+		t.Error("expected Priority to be nil")
+	}
+	if req.OwnerID != nil {
+		t.Error("expected OwnerID to be nil")
+	}
+	if req.Tags != nil {
+		t.Error("expected Tags to be nil")
+	}
+}
+
+func TestTaskUpdateParams_SetTags_Empty(t *testing.T) {
+	// Explicitly clearing tags
+	params := NewTaskUpdate().SetTags()
+
+	if !params.tagsSet {
+		t.Error("expected tagsSet to be true")
+	}
+	if len(params.tags) != 0 {
+		t.Errorf("expected empty tags, got %v", params.tags)
+	}
+
+	req := params.toUpdateTaskRequest(42)
+	if req.Tags == nil {
+		t.Error("expected Tags to be non-nil (empty slice)")
+	}
+	if len(req.Tags) != 0 {
+		t.Errorf("expected 0 tags, got %d", len(req.Tags))
+	}
+}
+
+func TestClient_UpdateTaskFromParams(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var req JSONRPCRequest
+		json.NewDecoder(r.Body).Decode(&req)
+
+		if req.Method != "updateTask" {
+			t.Errorf("expected method=updateTask, got %s", req.Method)
+		}
+
+		params := req.Params.(map[string]any)
+		if params["id"].(float64) != 42 {
+			t.Errorf("expected id=42, got %v", params["id"])
+		}
+		if params["title"] != "Updated via Params" {
+			t.Errorf("expected title='Updated via Params', got %v", params["title"])
+		}
+		if params["priority"].(float64) != 3 {
+			t.Errorf("expected priority=3, got %v", params["priority"])
+		}
+
+		resp := JSONRPCResponse{
+			JSONRPC: "2.0",
+			ID:      req.ID,
+			Result:  json.RawMessage(`true`),
+		}
+		json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL).WithAPIToken("test-token")
+
+	params := NewTaskUpdate().
+		SetTitle("Updated via Params").
+		SetPriority(3)
+
+	err := client.UpdateTaskFromParams(context.Background(), 42, params)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func TestClient_UpdateTaskFromParams_OnlySetFieldsSent(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var req JSONRPCRequest
+		json.NewDecoder(r.Body).Decode(&req)
+
+		params := req.Params.(map[string]any)
+
+		// Only title should be present, not priority or other fields
+		if _, hasTitle := params["title"]; !hasTitle {
+			t.Error("expected title to be present")
+		}
+		if _, hasPriority := params["priority"]; hasPriority {
+			t.Error("expected priority to NOT be present")
+		}
+		if _, hasOwner := params["owner_id"]; hasOwner {
+			t.Error("expected owner_id to NOT be present")
+		}
+
+		resp := JSONRPCResponse{
+			JSONRPC: "2.0",
+			ID:      req.ID,
+			Result:  json.RawMessage(`true`),
+		}
+		json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL).WithAPIToken("test-token")
+
+	// Only set title
+	params := NewTaskUpdate().SetTitle("Only Title")
+
+	err := client.UpdateTaskFromParams(context.Background(), 42, params)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}