Types (#57801)

* feat: 🎸 add Values<T>

* feat: 🎸 add UnionToIntersection<T> type

* refactor: 💡 use UnionToIntersection<T> in Canvas from @kbn/

* feat: 🎸 add PublicKeys<T> and PublicContract<T> types

* style: 💄 fix ESLint errors

packages/kbn-utility-types/README.md

@@ -20,8 +20,12 @@ type B = UnwrapPromise<A>; // string
 
 - `Ensure<T, X>` &mdash; Makes sure `T` is of type `X`.
 - `ObservableLike<T>` &mdash; Minimal interface for an object resembling an `Observable`.
+- `PublicContract<T>` &mdash; Returns an object with public keys only.
+- `PublicKeys<T>` &mdash; Returns public keys of an object.
 - `RecursiveReadonly<T>` &mdash; Like `Readonly<T>`, but freezes object recursively.
 - `ShallowPromise<T>` &mdash; Same as `Promise` type, but it flat maps the wrapped type.
+- `UnionToIntersection<T>` &mdash; Converts a union of types into an intersection.
 - `UnwrapObservable<T>` &mdash; Returns wrapped type of an observable.
 - `UnwrapPromise<T>` &mdash; Returns wrapped type of a promise.
 - `UnwrapPromiseOrReturn<T>` &mdash; Returns wrapped type of a promise or the type itself, if it isn't a promise.
+- `Values<T>` &mdash; Returns object or array value types.

packages/kbn-utility-types/index.ts

@@ -69,3 +69,31 @@ export type RecursiveReadonly<T> = T extends (...args: any) => any
   : T extends object
   ? Readonly<{ [K in keyof T]: RecursiveReadonly<T[K]> }>
   : T;
+
+/**
+ * Returns types or array or object values.
+ */
+export type Values<T> = T extends any[] ? T[number] : T extends object ? T[keyof T] : never;
+
+/**
+ * Utility type for converting a union of types into an intersection.
+ *
+ * This is a bit of "black magic" that will interpret a Union type as an Intersection
+ * type.  This is necessary in the case of distinguishing one collection from
+ * another.
+ */
+export type UnionToIntersection<U> = (U extends any
+? (k: U) => void
+: never) extends (k: infer I) => void
+  ? I
+  : never;
+
+/**
+ * Returns public keys of an object.
+ */
+export type PublicKeys<T> = keyof T;
+
+/**
+ * Returns an object with public keys only.
+ */
+export type PublicContract<T> = Pick<T, PublicKeys<T>>;

packages/kbn-utility-types/test-d/public_contract.ts

@@ -0,0 +1,33 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { expectType } from 'tsd';
+import { PublicContract } from '../index';
+
+class Test {
+  public str: string = '';
+  // @ts-ignore
+  private num: number = 0;
+}
+
+type CONTRACT = PublicContract<Test>;
+
+expectType<CONTRACT>({
+  str: 'foo',
+});

packages/kbn-utility-types/test-d/public_keys.ts

@@ -0,0 +1,31 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { expectType } from 'tsd';
+import { PublicKeys } from '../index';
+
+class Test {
+  public str: string = '';
+  // @ts-ignore
+  private num: number = 0;
+}
+
+type KEYS = PublicKeys<Test>;
+
+expectType<KEYS>('str');

packages/kbn-utility-types/test-d/union_to_intersection.ts

@@ -0,0 +1,28 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { expectType } from 'tsd';
+import { UnionToIntersection } from '../index';
+
+type INTERSECTED = UnionToIntersection<{ foo: 'bar' } | { baz: 'qux' }>;
+
+expectType<INTERSECTED>({
+  foo: 'bar',
+  baz: 'qux',
+});

packages/kbn-utility-types/test-d/values.ts

@@ -0,0 +1,38 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { expectType } from 'tsd';
+import { Values } from '../index';
+
+// Arrays
+type STRING = Values<string[]>;
+type ASDF_FOO = Values<Array<'asdf' | 'foo'>>;
+
+expectType<STRING>('adf');
+expectType<ASDF_FOO>('asdf');
+expectType<ASDF_FOO>('foo');
+
+// Objects
+type STRING2 = Values<Record<number, string>>;
+type FOO = Values<Record<number, 'foo'>>;
+type BAR = Values<{ foo: 'bar' }>;
+
+expectType<STRING2>('adf');
+expectType<FOO>('foo');
+expectType<BAR>('bar');

x-pack/legacy/plugins/canvas/i18n/functions/function_help.ts

@@ -5,7 +5,8 @@
  */
 
 import { ExpressionFunctionDefinition } from 'src/plugins/expressions';
-import { UnionToIntersection, CanvasFunction } from '../../types';
+import { UnionToIntersection } from '@kbn/utility-types';
+import { CanvasFunction } from '../../types';
 
 import { help as all } from './dict/all';
 import { help as alterColumn } from './dict/alter_column';

x-pack/legacy/plugins/canvas/types/functions.ts

@@ -10,22 +10,6 @@ import { functions as browserFunctions } from '../canvas_plugin_src/functions/br
 import { functions as serverFunctions } from '../canvas_plugin_src/functions/server';
 import { clientFunctions } from '../public/functions';
 
-/**
- * Utility type for converting a union of types into an intersection.
- *
- * This is a bit of "black magic" that will interpret a Union type as an Intersection
- * type.  This is necessary in this case of distiguishing one collection from
- * another in `FunctionError` and `FunctionStrings`.
- */
-// prettier-ignore
-export type UnionToIntersection<U> = 
-  (U extends any ? (k: U) => void : never) extends ((k: infer I) => void) ? I : never;
-
-/**
- * Utility type: gathers values of a collection as a type for use as a type.
- */
-export type ValuesOf<T extends any[]> = T[number];
-
 /**
  * A `ExpressionFunctionFactory` is a powerful type used for any function that produces
  * an `ExpressionFunction`. If it does not meet the signature for such a function,