♻️ Add types for auth form (#2446)

Author: KATO-Hiro

src/lib/types/auth_forms.ts

@@ -0,0 +1,84 @@
+/**
+ * Defines validation constraints that can be applied to form fields.
+ *
+ * @interface FieldConstraints
+ * @property {number} [minlength] - Minimum number of characters required for the field value
+ * @property {number} [maxlength] - Maximum number of characters allowed for the field value
+ * @property {boolean} [required] - Whether the field is mandatory and must have a value
+ * @property {string} [pattern] - Regular expression pattern that the field value must match
+ */
+type FieldConstraints = {
+  minlength?: number;
+  maxlength?: number;
+  required?: boolean;
+  pattern?: string;
+};
+
+type AuthFormConstraints = {
+  username?: FieldConstraints;
+  password?: FieldConstraints;
+};
+
+/**
+ * Represents the state and data structure for authentication forms.
+ *
+ * @interface AuthForm
+ * @property {string} id - Unique identifier for the form instance
+ * @property {boolean} valid - Indicates whether the form data passes validation
+ * @property {boolean} posted - Indicates whether the form has been submitted
+ * @property {Object} data - The form input data
+ * @property {string} data.username - The username field value
+ * @property {string} data.password - The password field value
+ * @property {Record<string, unknown>} errors - Collection of validation errors keyed by field name
+ * @property {AuthFormConstraints} [constraints] - Optional validation constraints for the form
+ * @property {Record<string, unknown>} [shape] - Optional form schema or structure definition
+ * @property {string} message - General message associated with the form (success, error, etc.)
+ */
+export type AuthForm = {
+  id: string;
+  valid: boolean;
+  posted: boolean;
+  data: { username: string; password: string };
+  errors: Record<string, unknown>;
+  constraints?: AuthFormConstraints;
+  shape?: Record<string, unknown>;
+  message: string;
+};
+
+/**
+ * Represents a strategy for creating authentication forms.
+ *
+ * @interface AuthFormCreationStrategy
+ * @property {string} name - The unique identifier or display name for this creation strategy
+ * @property {() => Promise<{ form: AuthForm }>} run - Asynchronous function that executes the strategy and returns the created authentication form
+ */
+export type AuthFormCreationStrategy = {
+  name: string;
+  run: () => Promise<{ form: AuthForm }>;
+};
+
+export type AuthFormCreationStrategies = AuthFormCreationStrategy[];
+
+/**
+ * Defines a validation strategy for authentication forms.
+ *
+ * A validation strategy encapsulates the logic for validating authentication
+ * form data from HTTP requests and returning the processed form object.
+ *
+ * @example
+ * ```typescript
+ * const loginStrategy: AuthFormValidationStrategy = {
+ *   name: 'login',
+ *   run: async (request) => {
+ *     // Validation logic here
+ *     return { form: validatedForm };
+ *   }
+ * };
+ * ```
+ */
+export type AuthFormValidationStrategy = {
+  name: string;
+  run: (request: Request) => Promise<{ form: AuthForm }>;
+};
+
+export type AuthFormValidationStrategies = AuthFormValidationStrategy[];

src/lib/utils/auth_forms.ts

@@ -3,9 +3,14 @@ import { redirect } from '@sveltejs/kit';
 import { superValidate } from 'sveltekit-superforms/server';
 import { zod } from 'sveltekit-superforms/adapters';
 
+import type {
+  AuthFormCreationStrategies,
+  AuthFormValidationStrategies,
+} from '$lib/types/auth_forms';
+
+import { authSchema } from '$lib/zod/schema';
 import { SEE_OTHER } from '$lib/constants/http-response-status-codes';
 import { HOME_PAGE } from '$lib/constants/navbar-links';
-import { authSchema } from '$lib/zod/schema';
 
 /**
  * Initialize authentication form pages (login/signup)
@@ -56,7 +61,7 @@ export const createAuthFormWithFallback = async () => {
  * https://superforms.rocks/concepts/client-validation
  * https://superforms.rocks/api#supervalidate-options
  */
-const formCreationStrategies = [
+const formCreationStrategies: AuthFormCreationStrategies = [
   {
     name: '(Basic case) Use standard superValidate',
     async run() {
@@ -112,7 +117,7 @@ export const validateAuthFormWithFallback = async (request: Request) => {
  * Form validation strategies for action handlers
  * Each strategy attempts a different approach to validate form data from requests
  */
-const formValidationStrategies = [
+const formValidationStrategies: AuthFormValidationStrategies = [
   {
     name: '(Basic Case) Use standard superValidate with request',
     async run(request: Request) {