Test: TypeScript type specification strength tests (#32905)

* Test: TypeScript type specification strength tests

* Chore: post-merge lint

* Post-merge conflict fix

package.json

@@ -48,6 +48,7 @@
     "test:ui:runner": "node scripts/functional_test_runner",
     "test:server": "grunt test:server",
     "test:coverage": "grunt test:coverage",
+    "typespec": "typings-tester --config x-pack/plugins/canvas/public/lib/aeroelastic/tsconfig.json x-pack/plugins/canvas/public/lib/aeroelastic/__fixtures__/typescript/typespec_tests.ts",
     "checkLicenses": "grunt licenses --dev",
     "build": "node scripts/build --all-platforms",
     "start": "node --trace-warnings --trace-deprecation scripts/kibana --dev ",
@@ -409,6 +410,7 @@
     "tslint-microsoft-contrib": "^6.0.0",
     "tslint-plugin-prettier": "^2.0.0",
     "typescript": "^3.3.3333",
+    "typings-tester": "^0.3.2",
     "vinyl-fs": "^3.0.2",
     "xml2js": "^0.4.19",
     "xmlbuilder": "9.0.4",

x-pack/plugins/canvas/public/lib/aeroelastic/__fixtures__/typescript/typespec_tests.ts

@@ -0,0 +1,82 @@
+import { select } from '../../select';
+import { Json, Selector } from '../..';
+
+/*
+
+  Type checking isn't too useful if future commits can accidentally weaken the type constraints, because a
+  TypeScript linter will not complain - everything that passed before will continue to pass. The coder
+  will not have feedback that the original intent with the typing got compromised. To declare the intent
+  via passing and failing type checks, test cases are needed, some of which designed to expect a TS pass,
+  some of them to expect a TS complaint. It documents intent for peers too, as type specs are a tough read.
+
+  Run compile-time type specification tests in the `kibana` root with:
+
+     yarn typespec
+
+  Test "cases" expecting to pass TS checks are not annotated, while ones we want TS to complain about
+  are prepended with the comment
+ 
+  // typings:expect-error
+
+  The test "suite" and "cases" are wrapped in IIFEs to prevent linters from complaining about the unused
+  binding. It can be structured internally as desired.
+  
+*/
+
+((): void => {
+  /**
+   * TYPE TEST SUITE
+   */
+
+  (function jsonTests(plain: Json): void {
+    // numbers are OK
+    plain = 1;
+    plain = NaN;
+    plain = Infinity;
+    plain = -Infinity;
+    plain = Math.pow(2, 6);
+    // other JSON primitive types are OK
+    plain = false;
+    plain = 'hello';
+    plain = null;
+    // structures made of above and of structures are OK
+    plain = {};
+    plain = [];
+    plain = { a: 1 };
+    plain = [0, null, false, NaN, 3.14, 'one more'];
+    plain = { a: { b: 5, c: { d: [1, 'a', -Infinity, null], e: -1 }, f: 'b' }, g: false };
+
+    // typings:expect-error
+    plain = undefined; // it's undefined
+    // typings:expect-error
+    plain = a => a; // it's a function
+    // typings:expect-error
+    plain = [new Date()]; // it's a time
+    // typings:expect-error
+    plain = { a: Symbol('haha') }; // symbol isn't permitted either
+    // typings:expect-error
+    plain = window || void 0;
+    // typings:expect-error
+    plain = { a: { b: 5, c: { d: [1, 'a', undefined, null] } } }; // going deep into the structure
+
+    return; // jsonTests
+  })(null);
+
+  (function selectTests(selector: Selector): void {
+    selector = select((a: Json) => a); // one arg
+    selector = select((a: Json, b: Json): Json => `${a} and ${b}`); // more args
+    selector = select(() => 1); // zero arg
+    selector = select((...args: Json[]) => args); // variadic
+
+    // typings:expect-error
+    selector = (a: Json) => a; // not a selector
+    // typings:expect-error
+    selector = select(() => {}); // should yield a JSON value, but it returns void
+    // typings:expect-error
+    selector = select((x: Json) => ({ a: x, b: undefined })); // should return a Json
+
+    return; // selectTests
+  })(select((a: Json) => a));
+
+  return; // test suite
+})();

x-pack/plugins/canvas/public/lib/aeroelastic/index.d.ts

@@ -4,6 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
+// linear algebra
 type f64 = number; // eventual AssemblyScript compatibility; doesn't hurt with vanilla TS either
 type f = f64; // shorthand
 
@@ -15,16 +16,36 @@ export type transformMatrix2d = [f, f, f, f, f, f, f, f, f] &
 export type transformMatrix3d = [f, f, f, f, f, f, f, f, f, f, f, f, f, f, f, f] &
   ReadonlyArray<f> & { __nominal: 'transformMatrix3d' };
 
+// plain, JSON-bijective value
+export type Json = JsonPrimitive | JsonArray | JsonMap;
+type JsonPrimitive = null | boolean | number | string;
+interface JsonArray extends Array<Json> {}
+interface JsonMap extends IMap<Json> {}
+interface IMap<T> {
+  [key: string]: T;
+}
+
+// state object
+export type State = JsonMap & WithActionId;
+export type ActionId = number;
+interface WithActionId {
+  primaryUpdate: { type: string; payload: { uid: ActionId; [propName: string]: Json } };
+  [propName: string]: Json; // allow other arbitrary props
+}
+
+// reselect-based data flow
+export type PlainFun = (...args: Json[]) => Json;
+export type Selector = (...fns: Resolve[]) => Resolve;
+type Resolve = ((obj: State) => Json);
+
+//
 export interface Meta {
   silent: boolean;
 }
-export type ActionId = number;
 export type TypeName = string;
-export type NodeResult = any;
-export type Payload = any;
-export type NodeFunction = (...args: any[]) => any;
-export type UpdaterFunction = (arg: NodeResult) => NodeResult;
+export type Payload = JsonMap;
+export type UpdaterFunction = (arg: State) => State;
 export type ChangeCallbackFunction = (
-  { type, state }: { type: TypeName; state: NodeResult },
+  { type, state }: { type: TypeName; state: State },
   meta: Meta
 ) => void;

x-pack/plugins/canvas/public/lib/aeroelastic/matrix.ts

@@ -24,7 +24,7 @@
  *
  */
 
-import { transformMatrix3d, vector3d } from './types';
+import { transformMatrix3d, vector3d } from '.';
 
 const NANMATRIX = [
   NaN,

x-pack/plugins/canvas/public/lib/aeroelastic/matrix2d.ts

@@ -4,7 +4,7 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { transformMatrix2d, vector2d } from './types';
+import { transformMatrix2d, vector2d } from '.';
 
 export const ORIGIN = [0, 0, 1] as vector2d;
 

x-pack/plugins/canvas/public/lib/aeroelastic/select.ts

@@ -4,13 +4,11 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { ActionId, NodeFunction, NodeResult } from './types';
+import { ActionId, Json, PlainFun, Selector, State } from '.';
 
-export const select = (fun: NodeFunction): NodeFunction => (...fns) => {
+export const select = (fun: PlainFun): Selector => (...fns) => {
   let prevId: ActionId = NaN;
-  let cache: NodeResult = null;
-  const old = (object: NodeResult): boolean =>
-    prevId === (prevId = object.primaryUpdate.payload.uid);
-  return (obj: NodeResult) =>
-    old(obj) ? cache : (cache = fun(...fns.map(f => f(obj) as NodeResult)));
+  let cache: Json = null;
+  const old = (object: State): boolean => prevId === (prevId = object.primaryUpdate.payload.uid);
+  return (obj: State) => (old(obj) ? cache : (cache = fun(...fns.map(f => f(obj) as State))));
 };

x-pack/plugins/canvas/public/lib/aeroelastic/store.ts

@@ -8,16 +8,16 @@ import {
   ActionId,
   ChangeCallbackFunction,
   Meta,
-  NodeResult,
   Payload,
+  State,
   TypeName,
   UpdaterFunction,
-} from './types';
+} from '.';
 
 let counter = 0 as ActionId;
 
 export const createStore = (
-  initialState: NodeResult,
+  initialState: State,
   updater: UpdaterFunction,
   onChangeCallback: ChangeCallbackFunction
 ) => {

x-pack/plugins/canvas/public/lib/aeroelastic/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "extends": "../../../../../tsconfig",
+  "compilerOptions": {
+    "module": "commonjs",
+    "lib": ["esnext", "dom"],
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "strictFunctionTypes": false,
+    "strictPropertyInitialization": true,
+    "noImplicitThis": true,
+    "noImplicitReturns": true,
+    "forceConsistentCasingInFileNames": true,
+    "noEmit": true,
+    "baseUrl": ".",
+    "paths": {
+      "layout/*": ["aeroelastic/*"]
+    },
+    "types": ["@kbn/x-pack/plugins/canvas/public/lib/aeroelastic"]
+  },
+  "exclude": ["node_modules", "**/*.spec.ts", "node_modules/@types/mocha"]
+}

x-pack/plugins/canvas/public/lib/dom.ts

@@ -4,11 +4,8 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { transformMatrix3d } from './aeroelastic/types';
+import { transformMatrix3d } from './aeroelastic';
 
 // converts a transform matrix to a CSS string
 export const matrixToCSS = (transformMatrix: transformMatrix3d): string =>
   transformMatrix ? 'matrix3d(' + transformMatrix.join(',') + ')' : 'translate3d(0,0,0)';
-
-// converts to string, and adds `px` if non-zero
-export const px = (value: number): string => (value === 0 ? '0' : value + 'px');

x-pack/tsconfig.json

@@ -8,7 +8,8 @@
     "test_utils/**/*"
   ],
   "exclude": [
-    "test/**/*"
+    "test/**/*",
+    "**/typespec_tests.ts"
   ],
   "compilerOptions": {
     "outDir": ".",

yarn.lock

@@ -6675,7 +6675,7 @@ commander@0.6.1:
   resolved "https://registry.yarnpkg.com/commander/-/commander-0.6.1.tgz#fa68a14f6a945d54dbbe50d8cdb3320e9e3b1a06"
   integrity sha1-+mihT2qUXVTbvlDYzbMyDp47GgY=
 
-commander@2, commander@2.19.0, commander@^2.11.0, commander@^2.12.1, commander@^2.19.0, commander@^2.9.0:
+commander@2, commander@2.19.0, commander@^2.11.0, commander@^2.12.1, commander@^2.12.2, commander@^2.19.0, commander@^2.9.0:
   version "2.19.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.19.0.tgz#f6198aa84e5b83c46054b94ddedbfed5ee9ff12a"
   integrity sha512-6tvAOO+D6OENvRAh524Dh9jcfKTYDQAqvqezbCW82xj5X0pSrcpxtvRKHLG0yBY6SD7PSDrJaj+0AiOcKVd1Xg==
@@ -23530,12 +23530,14 @@ typescript@^3.3.3333:
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.3.3333.tgz#171b2c5af66c59e9431199117a3bcadc66fdcfd6"
   integrity sha512-JjSKsAfuHBE/fB2oZ8NxtRTk5iGcg6hkYXMnZ3Wc+b2RSqejEqTaem11mHASMnFilHrax3sLK0GDzcJrekZYLw==
 
-ua-parser-js@^0.7.18:
-  version "0.7.18"
-  resolved "https://registry.yarnpkg.com/ua-parser-js/-/ua-parser-js-0.7.18.tgz#a7bfd92f56edfb117083b69e31d2aa8882d4b1ed"
-  integrity sha512-LtzwHlVHwFGTptfNSgezHp7WUlwiqb0gA9AALRbKaERfxwJoiX0A73QbTToxteIAuIaFshhgIZfqK8s7clqgnA==
+typings-tester@^0.3.2:
+  version "0.3.2"
+  resolved "https://registry.yarnpkg.com/typings-tester/-/typings-tester-0.3.2.tgz#04cc499d15ab1d8b2d14dd48415a13d01333bc5b"
+  integrity sha512-HjGoAM2UoGhmSKKy23TYEKkxlphdJFdix5VvqWFLzH1BJVnnwG38tpC6SXPgqhfFGfHY77RlN1K8ts0dbWBQ7A==
+  dependencies:
+    commander "^2.12.2"
 
-ua-parser-js@^0.7.9:
+ua-parser-js@^0.7.18, ua-parser-js@^0.7.9:
   version "0.7.19"
   resolved "https://registry.yarnpkg.com/ua-parser-js/-/ua-parser-js-0.7.19.tgz#94151be4c0a7fb1d001af7022fdaca4642659e4b"
   integrity sha512-T3PVJ6uz8i0HzPxOF9SWzWAlfN/DavlpQqepn22xgve/5QecC+XMCAtmUNnY7C9StehaV6exjUCI801lOI7QlQ==