feat: add form validation

src/hooks/useFetchState.ts

@@ -0,0 +1,15 @@
+import { useState } from 'react'
+
+export const fetchState = ['idle', 'loading', 'error', 'success'] as const
+
+export type FetchState = typeof fetchState[number]
+
+export const useFetchState = (
+  initialFetchState: FetchState = 'idle'
+): [
+  fetchState: FetchState,
+  setFetchState: React.Dispatch<React.SetStateAction<FetchState>>
+] => {
+  const [fetchState, setFetchState] = useState<FetchState>(initialFetchState)
+  return [fetchState, setFetchState]
+}

src/hooks/useForm.ts

@@ -0,0 +1,144 @@
+import { useMemo, useState } from 'react'
+import { Static, TObject, TProperties, Type } from '@sinclair/typebox'
+import type { ErrorObject } from 'ajv'
+
+import type { HandleForm } from '../components/Form'
+import { FetchState, useFetchState } from './useFetchState'
+import { ajv } from '../utils/ajv'
+import { handleCheckboxBoolean } from '../utils/handleCheckboxBoolean'
+import { handleOptionalEmptyStringToNull } from '../utils/handleOptionalEmptyStringToNull'
+
+export type Error = ErrorObject
+
+export type ErrorsObject<K extends TProperties> = {
+  [key in keyof Partial<K>]: Error[] | undefined
+}
+
+export type HandleSubmitCallback<K extends TProperties> = (
+  formData: Static<TObject<K>>,
+  formElement: HTMLFormElement
+) => Promise<Message<K> | null>
+
+export type HandleSubmit<K extends TProperties> = (
+  callback: HandleSubmitCallback<K>
+) => HandleForm
+
+export interface GlobalMessage {
+  type: 'error' | 'success'
+  value?: string
+  properties?: undefined
+}
+
+export interface PropertiesMessage<K extends TProperties> {
+  type: 'error'
+  value?: string
+  properties: { [key in keyof Partial<K>]: string }
+}
+
+export type Message<K extends TProperties> =
+  | GlobalMessage
+  | PropertiesMessage<K>
+
+export interface UseFormResult<K extends TProperties> {
+  handleSubmit: HandleSubmit<K>
+
+  readonly fetchState: FetchState
+  setFetchState: React.Dispatch<React.SetStateAction<FetchState>>
+
+  /**
+   * Global message of the form (not specific to a property).
+   */
+  readonly message: string | null
+  setMessage: React.Dispatch<React.SetStateAction<string | null>>
+
+  /**
+   * Errors for each property.
+   *
+   * The array will always have at least one element (never empty) in case of errors.
+   *
+   * `undefined` means no errors.
+   */
+  readonly errors: ErrorsObject<K>
+}
+
+export const useForm = <K extends TProperties>(
+  validationSchema: K
+): UseFormResult<typeof validationSchema> => {
+  const validationSchemaObject = useMemo(() => {
+    return Type.Object(validationSchema)
+  }, [validationSchema])
+
+  const [fetchState, setFetchState] = useFetchState()
+  const [message, setMessage] = useState<string | null>(null)
+  const [errors, setErrors] = useState<ErrorsObject<typeof validationSchema>>(
+    {} as any
+  )
+
+  const validate = useMemo(() => {
+    return ajv.compile(validationSchemaObject)
+  }, [validationSchemaObject])
+
+  const handleSubmit: HandleSubmit<typeof validationSchema> = (callback) => {
+    return async (formData, formElement) => {
+      setErrors({} as any)
+      setMessage(null)
+      formData = handleOptionalEmptyStringToNull(
+        formData,
+        validationSchemaObject.required
+      )
+      formData = handleCheckboxBoolean(formData, validationSchemaObject)
+      const isValid = validate(formData)
+      if (!isValid) {
+        setFetchState('error')
+        const errors: ErrorsObject<typeof validationSchema> = {} as any
+        for (const property in validationSchemaObject.properties) {
+          const errorsForProperty = validate.errors?.filter((error) => {
+            return error.instancePath === `/${property}`
+          })
+          errors[property as keyof typeof validationSchema] =
+            errorsForProperty != null && errorsForProperty.length > 0
+              ? errorsForProperty
+              : undefined
+        }
+        setErrors(errors)
+      } else {
+        setErrors({} as any)
+        setFetchState('loading')
+        const message = await callback(
+          formData as Static<TObject<typeof validationSchema>>,
+          formElement
+        )
+        if (message != null) {
+          const { value = null, type, properties } = message
+          setMessage(value)
+          setFetchState(type)
+          if (type === 'error') {
+            const propertiesErrors: ErrorsObject<typeof validationSchema> =
+              {} as any
+            for (const property in properties) {
+              propertiesErrors[property] = [
+                {
+                  keyword: 'message',
+                  message: properties[property],
+                  instancePath: `/${property}`,
+                  schemaPath: `#/properties/${property}/message`,
+                  params: {}
+                }
+              ]
+            }
+            setErrors(propertiesErrors)
+          }
+        }
+      }
+    }
+  }
+
+  return {
+    handleSubmit,
+    fetchState,
+    setFetchState,
+    message,
+    setMessage,
+    errors
+  }
+}