fix: resolve issue #1 - 🎯 Fix premature termination in API pagination when page size is less than requested

client.go

@@ -0,0 +1,96 @@
+package cli
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+)
+
+// Item represents an item returned from the API.
+type Item struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+}
+
+// PageResponse represents a paginated API response body.
+type PageResponse struct {
+	Items []Item `json:"items"`
+}
+
+// Client handles API communication.
+type Client struct {
+	BaseURL    string
+	HTTPClient *http.Client
+}
+
+// NewClient creates a new Client instance.
+func NewClient(baseURL string, httpClient *http.Client) *Client {
+	if httpClient == nil {
+		httpClient = http.DefaultClient
+	}
+	return &Client{
+		BaseURL:    baseURL,
+		HTTPClient: httpClient,
+	}
+}
+
+// FetchAllItems retrieves all items across all pages.
+// Fixed premature termination when server returns fewer items per page than requestedPageSize.
+func (c *Client) FetchAllItems(ctx context.Context, requestedPageSize int) ([]Item, error) {
+	var allItems []Item
+	page := 1
+
+	for {
+		items, err := c.FetchPage(ctx, page, requestedPageSize)
+		if err != nil {
+			return nil, err
+		}
+
+		if len(items) == 0 {
+			break
+		}
+
+		allItems = append(allItems, items...)
+		page++
+	}
+
+	return allItems, nil
+}
+
+// FetchPage retrieves a single page of items from the API.
+func (c *Client) FetchPage(ctx context.Context, page, pageSize int) ([]Item, error) {
+	u, err := url.Parse(fmt.Sprintf("%s/items", c.BaseURL))
+	if err != nil {
+		return nil, err
+	}
+
+	q := u.Query()
+	q.Set("page", strconv.Itoa(page))
+	q.Set("page_size", strconv.Itoa(pageSize))
+	u.RawQuery = q.Encode()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
+	}
+
+	var pageResp PageResponse
+	if err := json.NewDecoder(resp.Body).Decode(&pageResp); err != nil {
+		return nil, err
+	}
+
+	return pageResp.Items, nil
+}