chore: move utils directory into shared/lib

src/shared/lib/utils/buildQueryString.ts

@@ -0,0 +1,79 @@
+/**
+ * Build query string from URL parameters
+ *
+ * Generic, type-safe function to build properly encoded query strings
+ * from URL parameters. Supports primitives, arrays, and optional values.
+ *
+ * @param params - Object containing query parameters
+ * @returns Encoded query string (empty string if no parameters)
+ *
+ * @example
+ * ```ts
+ * buildQueryString({ category: 'serif', subsets: ['latin', 'latin-ext'] })
+ * // Returns: "category=serif&subsets=latin&subsets=latin-ext"
+ *
+ * buildQueryString({ limit: 50, page: 1 })
+ * // Returns: "limit=50&page=1"
+ *
+ * buildQueryString({})
+ * // Returns: ""
+ *
+ * buildQueryString({ search: 'hello world', active: true })
+ * // Returns: "search=hello%20world&active=true"
+ * ```
+ */
+
+/**
+ * Query parameter value type
+ * Supports primitives, arrays, and excludes null/undefined
+ */
+export type QueryParamValue = string | number | boolean | string[] | number[];
+
+/**
+ * Query parameters object
+ */
+export type QueryParams = Record<string, QueryParamValue | undefined | null>;
+
+/**
+ * Build query string from URL parameters
+ *
+ * Handles:
+ * - Primitive values (string, number, boolean)
+ * - Arrays (multiple values with same key)
+ * - Optional values (excludes undefined/null)
+ * - Proper URL encoding
+ *
+ * Edge cases:
+ * - Empty object → empty string
+ * - No parameters → empty string
+ * - Nested objects → flattens to string representation
+ * - Special characters → proper encoding
+ *
+ * @param params - Object containing query parameters
+ * @returns Encoded query string (with "?" prefix if non-empty)
+ */
+export function buildQueryString(params: QueryParams): string {
+    const searchParams = new URLSearchParams();
+
+    for (const [key, value] of Object.entries(params)) {
+        // Skip undefined/null values
+        if (value === undefined || value === null) {
+            continue;
+        }
+
+        // Handle arrays (multiple values with same key)
+        if (Array.isArray(value)) {
+            for (const item of value) {
+                if (item !== undefined && item !== null) {
+                    searchParams.append(key, String(item));
+                }
+            }
+        } else {
+            // Handle primitives
+            searchParams.append(key, String(value));
+        }
+    }
+
+    const queryString = searchParams.toString();
+    return queryString ? `?${queryString}` : '';
+}