feat: joi typings with IN and OUT types

src/validation/joi/joi.model.ts

@@ -12,20 +12,24 @@ import {
   StringSchema,
 } from '@hapi/joi'
 
-export type SchemaTyped<T> =
-  | AnySchemaT<T>
-  | ArraySchemaTyped<T>
-  | AlternativesSchemaTyped<T>
+export type SchemaTyped<IN, OUT = IN> =
+  | AnySchemaT<IN, OUT>
+  | ArraySchemaTyped<IN>
+  | AlternativesSchemaTyped<IN>
   | BinarySchemaTyped
   | BooleanSchemaTyped
-  | DateSchemaTyped<T>
-  | FunctionSchemaTyped<T>
+  | DateSchemaTyped<IN>
+  | FunctionSchemaTyped<IN>
   | NumberSchemaTyped
-  | ObjectSchemaTyped<T>
+  | ObjectSchemaTyped<IN, OUT>
   | StringSchemaTyped
-  | LazySchemaTyped<T>
+  | LazySchemaTyped<IN>
 
-export interface AnySchemaT<T> extends AnySchema {}
+/**
+ * IN - value before validation/conversion
+ * OUT - value after validation/conversion (can be different due to conversion, stripping, etc)
+ */
+export interface AnySchemaT<IN, OUT = IN> extends AnySchema {}
 
 export interface ArraySchemaTyped<T> extends ArraySchema, AnySchemaT<T[]> {}
 export interface AlternativesSchemaTyped<T> extends AlternativesSchema {}
@@ -34,6 +38,6 @@ export interface BooleanSchemaTyped extends BooleanSchema, AnySchemaT<boolean> {
 export interface DateSchemaTyped<T> extends DateSchema {}
 export interface FunctionSchemaTyped<T> extends FunctionSchema {}
 export interface NumberSchemaTyped extends NumberSchema, AnySchemaT<number> {}
-export interface ObjectSchemaTyped<T> extends ObjectSchema, AnySchemaT<T> {}
+export interface ObjectSchemaTyped<IN, OUT> extends ObjectSchema, AnySchemaT<IN, OUT> {}
 export interface StringSchemaTyped extends StringSchema, AnySchemaT<string> {}
 export interface LazySchemaTyped<T> extends LazySchema {}

src/validation/joi/joi.shared.schemas.ts

@@ -9,13 +9,13 @@ export const integerSchema = Joi.number().integer()
 export const dateStringSchema = stringSchema.dateString()
 export const binarySchema = Joi.binary()
 
-export function arraySchema<T> (items?: AnySchemaT<T>): ArraySchemaTyped<T> {
+export function arraySchema<T> (items?: AnySchemaT<T, T>): ArraySchemaTyped<T> {
   return items ? Joi.array().items(items) : Joi.array()
 }
 
-export function objectSchema<T> (
-  schema?: { [key in keyof T]: AnySchemaT<T[key]> },
-): ObjectSchemaTyped<T> {
+export function objectSchema<IN, OUT = IN> (
+  schema?: { [key in keyof IN]: AnySchemaT<IN[key]> },
+): ObjectSchemaTyped<IN, OUT> {
   return Joi.object(schema)
 }
 

src/validation/joi/joi.validation.util.ts

@@ -41,13 +41,18 @@ const defaultOptions: ValidationOptions = {
  *
  * If `schema` is undefined - returns value as is.
  */
-export function validate<T> (
-  value: T,
-  schema?: AnySchemaT<T>,
+export function validate<IN, OUT = IN> (
+  value: IN,
+  schema?: AnySchemaT<IN, OUT>,
   objectName?: string,
   options: ValidationOptions = {},
-): T {
-  const { value: returnValue, error } = getValidationResult(value, schema, objectName, options)
+): OUT {
+  const { value: returnValue, error } = getValidationResult<IN, OUT>(
+    value,
+    schema,
+    objectName,
+    options,
+  )
 
   if (error) {
     throw error
@@ -63,21 +68,21 @@ export function validate<T> (
  *
  * If `schema` is undefined - returns value as is.
  */
-export function getValidationResult<T> (
-  value: T,
-  schema?: AnySchemaT<T>,
+export function getValidationResult<IN, OUT = IN> (
+  value: IN,
+  schema?: AnySchemaT<IN, OUT>,
   objectName?: string,
   options: ValidationOptions = {},
-): JoiValidationResult<T> {
-  if (!schema) return { value }
+): JoiValidationResult<OUT> {
+  if (!schema) return { value } as any
 
   const { value: returnValue, error } = Joi.validate(value, schema, {
     ...defaultOptions,
     ...options,
   })
 
-  const vr: JoiValidationResult<T> = {
-    value: returnValue,
+  const vr: JoiValidationResult<OUT> = {
+    value: (returnValue as any) as OUT,
   }
 
   if (error) {