Code review

packages/jest-validate/README.md

@@ -79,7 +79,7 @@ You will find examples of `condition`, `deprecate`, `error`, `unknown`, and `dep
 
 - it matches the JavaScript type of the example value, e.g. `string`, `number`, `array`, `boolean`, `function`, or `object`
 - it is `null` or `undefined`
-- the example value is an array where the first element is the special value `MultipleValidOptions`, and the value matches the type of _any_ of the other values in the array
+- it matches the Javascript type of any of arguments passed to `MultipleValidOptions(...)`
 
 The last condition is a special syntax that allows validating where more than one type is permissible; see example below. It's acceptable to have multiple values of the same type in the example, so you can also use this syntax to provide more than one example. When a validation failure occurs, the error message will show all other values in the array as examples.
 
@@ -145,7 +145,7 @@ import {MultipleValidOptions} from 'jest-validate';
 
 validate(config, {
   // `bar` will accept either a string or a number
-  bar: [MultipleValidOptions, 'string is ok', 2],
+  bar: MultipleValidOptions('string is ok', 2),
 });
 ```
 

packages/jest-validate/src/__tests__/__snapshots__/validate.test.js.snap

@@ -4,7 +4,7 @@ exports[`Repeated types within multiple valid examples are coalesced in error re
 "<red><bold><bold>●<bold> Validation Error</>:</>
 <red></>
 <red>  Option <bold>\\"foo\\"</> must be of type:</>
-<red>    <bold><green>string or number<red></></>
+<red>    <bold><green>string<red></> or <bold><green>number<red></></>
 <red>  but instead received:</>
 <red>    <bold><red>boolean<red></></>
 <red></>
@@ -138,7 +138,7 @@ exports[`reports errors nicely when failing with multiple valid options 1`] = `
 "<red><bold><bold>●<bold> Validation Error</>:</>
 <red></>
 <red>  Option <bold>\\"foo\\"</> must be of type:</>
-<red>    <bold><green>string or array<red></></>
+<red>    <bold><green>string<red></> or <bold><green>array<red></></>
 <red>  but instead received:</>
 <red>    <bold><red>number<red></></>
 <red></>

packages/jest-validate/src/__tests__/validate.test.js

@@ -210,7 +210,7 @@ test('works with custom deprecations', () => {
 
 test('works with multiple valid types', () => {
   const exampleConfig = {
-    foo: [MultipleValidOptions, 'text', ['text']],
+    foo: MultipleValidOptions('text', ['text']),
   };
 
   expect(
@@ -239,7 +239,7 @@ test('works with multiple valid types', () => {
 
 test('reports errors nicely when failing with multiple valid options', () => {
   const exampleConfig = {
-    foo: [MultipleValidOptions, 'text', ['text']],
+    foo: MultipleValidOptions('text', ['text']),
   };
 
   expect(() =>
@@ -254,7 +254,7 @@ test('reports errors nicely when failing with multiple valid options', () => {
 
 test('Repeated types within multiple valid examples are coalesced in error report', () => {
   const exampleConfig = {
-    foo: [MultipleValidOptions, 'foo', 'bar', 2],
+    foo: MultipleValidOptions('foo', 'bar', 2),
   };
 
   expect(() =>

packages/jest-validate/src/condition.js

@@ -9,7 +9,7 @@
 
 const toString = Object.prototype.toString;
 
-export const MultipleValidOptions = Symbol('JEST_MULTIPLE_VALID_OPTIONS');
+const MultipleValidOptionsSymbol = Symbol('JEST_MULTIPLE_VALID_OPTIONS');
 
 function validationConditionSingle(option: any, validOption: any): boolean {
   return (
@@ -19,19 +19,21 @@ function validationConditionSingle(option: any, validOption: any): boolean {
   );
 }
 
-export function getConditions(validOption: any) {
+export function getValues(validOption: any) {
   if (
     Array.isArray(validOption) &&
     validOption.length &&
-    validOption[0] === MultipleValidOptions
+    validOption[0] === MultipleValidOptionsSymbol
   ) {
     return validOption.slice(1);
   }
   return [validOption];
 }
 
 export function validationCondition(option: any, validOption: any): boolean {
-  return getConditions(validOption).some(e =>
-    validationConditionSingle(option, e),
-  );
+  return getValues(validOption).some(e => validationConditionSingle(option, e));
+}
+
+export function MultipleValidOptions(...args: Array<any>) {
+  return [MultipleValidOptionsSymbol, ...args];
 }

packages/jest-validate/src/errors.js

@@ -12,7 +12,7 @@ import type {ValidationOptions} from './types';
 import chalk from 'chalk';
 import getType from 'jest-get-type';
 import {formatPrettyObject, ValidationError, ERROR} from './utils';
-import {getConditions} from './condition';
+import {getValues} from './condition';
 
 export const errorMessage = (
   option: string,
@@ -21,16 +21,15 @@ export const errorMessage = (
   options: ValidationOptions,
   path?: Array<string>,
 ): void => {
-  const conditions = getConditions(defaultValue);
-  const validTypes = conditions
-    .map(getType)
-    .filter(uniqueFilter())
-    .join(' or ');
+  const conditions = getValues(defaultValue);
+  const validTypes: Array<string> = Array.from(
+    new Set(conditions.map(getType)),
+  );
 
   const message = `  Option ${chalk.bold(
     `"${path && path.length > 0 ? path.join('.') + '.' : ''}${option}"`,
   )} must be of type:
-    ${chalk.bold.green(validTypes)}
+    ${validTypes.map(e => chalk.bold.green(e)).join(' or ')}
   but instead received:
     ${chalk.bold.red(getType(received))}
 
@@ -54,13 +53,3 @@ function formatExamples(option: string, examples: Array<any>) {
 
 `);
 }
-
-function uniqueFilter() {
-  const seen: {[string]: any} = {};
-  return function(key) {
-    if (seen[key]) {
-      return false;
-    }
-    return (seen[key] = true);
-  };
-}