From 85ab4120a455d1fb1e9ff34b800c19e1726388fe Mon Sep 17 00:00:00 2001
From: Pierre Gayvallet <pierre.gayvallet@elastic.co>
Date: Tue, 21 Apr 2020 07:43:35 +0200
Subject: [PATCH] kbn/config-schema: Consider maybe properties as optional keys
 in ObjectType (#63838)

* consider optional properties as optional keys in ObjectType

* fix type on security config

* fix ObjectTypeOptions
---
 .../src/types/object_type.test.ts             | 24 +++++++++++++++++++
 .../src/types/object_type.ts                  | 23 ++++++++++++++----
 .../server/http/router/validator/validator.ts | 17 +++++++++----
 3 files changed, 55 insertions(+), 9 deletions(-)

diff --git a/packages/kbn-config-schema/src/types/object_type.test.ts b/packages/kbn-config-schema/src/types/object_type.test.ts
index 47a0f5f7a5491..5ab59d1c02077 100644
--- a/packages/kbn-config-schema/src/types/object_type.test.ts
+++ b/packages/kbn-config-schema/src/types/object_type.test.ts
@@ -18,6 +18,7 @@
  */
 
 import { schema } from '..';
+import { TypeOf } from './object_type';
 
 test('returns value by default', () => {
   const type = schema.object({
@@ -350,3 +351,26 @@ test('unknowns = `ignore` affects only own keys', () => {
     })
   ).toThrowErrorMatchingInlineSnapshot(`"[foo.baz]: definition for this key is missing"`);
 });
+
+test('handles optional properties', () => {
+  const type = schema.object({
+    required: schema.string(),
+    optional: schema.maybe(schema.string()),
+  });
+
+  type SchemaType = TypeOf<typeof type>;
+
+  let foo: SchemaType = {
+    required: 'foo',
+  };
+  foo = {
+    required: 'hello',
+    optional: undefined,
+  };
+  foo = {
+    required: 'hello',
+    optional: 'bar',
+  };
+
+  expect(foo).toBeDefined();
+});
diff --git a/packages/kbn-config-schema/src/types/object_type.ts b/packages/kbn-config-schema/src/types/object_type.ts
index 5a50e714a5931..fee2d02c1bfb9 100644
--- a/packages/kbn-config-schema/src/types/object_type.ts
+++ b/packages/kbn-config-schema/src/types/object_type.ts
@@ -26,9 +26,26 @@ export type Props = Record<string, Type<any>>;
 
 export type TypeOf<RT extends Type<any>> = RT['type'];
 
+type OptionalProperties<Base extends Props> = Pick<
+  Base,
+  {
+    [Key in keyof Base]: undefined extends TypeOf<Base[Key]> ? Key : never;
+  }[keyof Base]
+>;
+
+type RequiredProperties<Base extends Props> = Pick<
+  Base,
+  {
+    [Key in keyof Base]: undefined extends TypeOf<Base[Key]> ? never : Key;
+  }[keyof Base]
+>;
+
 // Because of https://github.com/Microsoft/TypeScript/issues/14041
 // this might not have perfect _rendering_ output, but it will be typed.
-export type ObjectResultType<P extends Props> = Readonly<{ [K in keyof P]: TypeOf<P[K]> }>;
+export type ObjectResultType<P extends Props> = Readonly<
+  { [K in keyof OptionalProperties<P>]?: TypeOf<P[K]> } &
+    { [K in keyof RequiredProperties<P>]: TypeOf<P[K]> }
+>;
 
 interface UnknownOptions {
   /**
@@ -40,9 +57,7 @@ interface UnknownOptions {
   unknowns?: 'allow' | 'ignore' | 'forbid';
 }
 
-export type ObjectTypeOptions<P extends Props = any> = TypeOptions<
-  { [K in keyof P]: TypeOf<P[K]> }
-> &
+export type ObjectTypeOptions<P extends Props = any> = TypeOptions<ObjectResultType<P>> &
   UnknownOptions;
 
 export class ObjectType<P extends Props = any> extends Type<ObjectResultType<P>> {
diff --git a/src/core/server/http/router/validator/validator.ts b/src/core/server/http/router/validator/validator.ts
index 6c766e69f0f37..a2299b47ae253 100644
--- a/src/core/server/http/router/validator/validator.ts
+++ b/src/core/server/http/router/validator/validator.ts
@@ -17,7 +17,14 @@
  * under the License.
  */
 
-import { ValidationError, Type, schema, ObjectType, isConfigSchema } from '@kbn/config-schema';
+import {
+  ValidationError,
+  Type,
+  schema,
+  ObjectType,
+  TypeOf,
+  isConfigSchema,
+} from '@kbn/config-schema';
 import { Stream } from 'stream';
 import { RouteValidationError } from './validator_error';
 
@@ -85,7 +92,7 @@ type RouteValidationResultType<T extends RouteValidationSpec<any> | undefined> =
   T extends RouteValidationFunction<any>
     ? ReturnType<T>['value']
     : T extends Type<any>
-    ? ReturnType<T['validate']>
+    ? TypeOf<T>
     : undefined
 >;
 
@@ -170,7 +177,7 @@ export class RouteValidator<P = {}, Q = {}, B = {}> {
    * @internal
    */
   public getParams(data: unknown, namespace?: string): Readonly<P> {
-    return this.validate(this.config.params, this.options.unsafe?.params, data, namespace);
+    return this.validate(this.config.params, this.options.unsafe?.params, data, namespace) as P;
   }
 
   /**
@@ -178,7 +185,7 @@ export class RouteValidator<P = {}, Q = {}, B = {}> {
    * @internal
    */
   public getQuery(data: unknown, namespace?: string): Readonly<Q> {
-    return this.validate(this.config.query, this.options.unsafe?.query, data, namespace);
+    return this.validate(this.config.query, this.options.unsafe?.query, data, namespace) as Q;
   }
 
   /**
@@ -186,7 +193,7 @@ export class RouteValidator<P = {}, Q = {}, B = {}> {
    * @internal
    */
   public getBody(data: unknown, namespace?: string): Readonly<B> {
-    return this.validate(this.config.body, this.options.unsafe?.body, data, namespace);
+    return this.validate(this.config.body, this.options.unsafe?.body, data, namespace) as B;
   }
 
   /**