Fix pretty print for closeTo matcher (#12626)

CHANGELOG.md

@@ -59,6 +59,7 @@
 - `[expect]` Move typings of `.not`, `.rejects` and `.resolves` modifiers outside of `Matchers` interface ([#12346](https://github.com/facebook/jest/pull/12346))
 - `[expect]` Throw useful error if `expect.extend` is called with invalid matchers ([#12488](https://github.com/facebook/jest/pull/12488))
 - `[expect]` Fix `iterableEquality` ignores other properties ([#8359](https://github.com/facebook/jest/pull/8359))
+- `[expect]` Fix print for the `closeTo` matcher ([#12626](https://github.com/facebook/jest/pull/12626))
 - `[jest-circus, @jest/types]` Disallow undefined value in `TestContext` type ([#12507](https://github.com/facebook/jest/pull/12507))
 - `[jest-config]` Correctly detect CI environment and update snapshots accordingly ([#12378](https://github.com/facebook/jest/pull/12378))
 - `[jest-config]` Pass `moduleTypes` to `ts-node` to enforce CJS when transpiling ([#12397](https://github.com/facebook/jest/pull/12397))

packages/expect/src/asymmetricMatchers.ts

@@ -13,6 +13,7 @@ import {
   subsetEquality,
 } from '@jest/expect-utils';
 import * as matcherUtils from 'jest-matcher-utils';
+import {pluralize} from 'jest-util';
 import {getState} from './jestMatchersObject';
 import type {
   AsymmetricMatcher as AsymmetricMatcherInterface,
@@ -329,6 +330,14 @@ class CloseTo extends AsymmetricMatcher<number> {
   override getExpectedType() {
     return 'number';
   }
+
+  override toAsymmetricMatcher(): string {
+    return [
+      this.toString(),
+      this.sample,
+      `(${pluralize('digit', this.precision)})`,
+    ].join(' ');
+  }
 }
 
 export const any = (expectedObject: unknown): Any => new Any(expectedObject);

packages/expect/src/index.ts

@@ -49,6 +49,7 @@ import type {
   ThrowingMatcherFn,
 } from './types';
 
+export {AsymmetricMatcher} from './asymmetricMatchers';
 export type {
   AsymmetricMatchers,
   BaseExpect,

packages/pretty-format/package.json

@@ -29,6 +29,7 @@
     "@types/react": "*",
     "@types/react-is": "^17.0.0",
     "@types/react-test-renderer": "*",
+    "expect": "^28.0.0-alpha.8",
     "immutable": "^4.0.0",
     "jest-util": "^28.0.0-alpha.8",
     "react": "*",

packages/pretty-format/src/__tests__/AsymmetricMatcher.test.ts

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {AsymmetricMatcher as AbstractAsymmetricMatcher} from 'expect';
 import prettyFormat, {plugins} from '../';
 import type {OptionsReceived} from '../types';
 
@@ -131,6 +132,42 @@ test('stringNotMatching(string)', () => {
   expect(result).toEqual('StringNotMatching /jest/');
 });
 
+test('closeTo(number, precision)', () => {
+  const result = prettyFormat(expect.closeTo(1.2345, 4), options);
+  expect(result).toEqual('NumberCloseTo 1.2345 (4 digits)');
+});
+
+test('notCloseTo(number, precision)', () => {
+  const result = prettyFormat(expect.not.closeTo(1.2345, 1), options);
+  expect(result).toEqual('NumberNotCloseTo 1.2345 (1 digit)');
+});
+
+test('closeTo(number)', () => {
+  const result = prettyFormat(expect.closeTo(1.2345), options);
+  expect(result).toEqual('NumberCloseTo 1.2345 (2 digits)');
+});
+
+test('closeTo(Infinity)', () => {
+  const result = prettyFormat(expect.closeTo(-Infinity), options);
+  expect(result).toEqual('NumberCloseTo -Infinity (2 digits)');
+});
+
+test('closeTo(scientific number)', () => {
+  const result = prettyFormat(expect.closeTo(1.56e-3, 4), options);
+  expect(result).toEqual('NumberCloseTo 0.00156 (4 digits)');
+});
+
+test('closeTo(very small scientific number)', () => {
+  const result = prettyFormat(expect.closeTo(1.56e-10, 4), options);
+  expect(result).toEqual('NumberCloseTo 1.56e-10 (4 digits)');
+});
+
+test('correctly handles inability to pretty-print matcher', () => {
+  expect(() => prettyFormat(new DummyMatcher(1), options)).toThrow(
+    'Asymmetric matcher DummyMatcher does not implement toAsymmetricMatcher()',
+  );
+});
+
 test('supports multiple nested asymmetric matchers', () => {
   const result = prettyFormat(
     {
@@ -311,3 +348,21 @@ test('min option', () => {
     '{"test": {"nested": ObjectContaining {"a": ArrayContaining [1], "b": Anything, "c": Any<String>, "d": StringContaining "jest", "e": StringMatching /jest/, "f": ObjectContaining {"test": "case"}}}}',
   );
 });
+
+class DummyMatcher extends AbstractAsymmetricMatcher<number> {
+  constructor(sample: number) {
+    super(sample);
+  }
+
+  asymmetricMatch(other: number) {
+    return this.sample === other;
+  }
+
+  toString() {
+    return 'DummyMatcher';
+  }
+
+  override getExpectedType() {
+    return 'number';
+  }
+}

packages/pretty-format/src/plugins/AsymmetricMatcher.ts

@@ -80,6 +80,12 @@ export const serialize: NewPlugin['serialize'] = (
     );
   }
 
+  if (typeof val.toAsymmetricMatcher !== 'function') {
+    throw new Error(
+      `Asymmetric matcher ${val.constructor.name} does not implement toAsymmetricMatcher()`,
+    );
+  }
+
   return val.toAsymmetricMatcher();
 };
 

packages/pretty-format/tsconfig.json

@@ -6,5 +6,6 @@
   },
   "include": ["./src/**/*"],
   "exclude": ["./**/__tests__/**/*"],
+  // no `expect`, only used in tests
   "references": [{"path": "../jest-schemas"}, {"path": "../jest-util"}]
 }

scripts/buildTs.mjs

@@ -62,6 +62,13 @@ import {getPackages} from './buildUtils.mjs';
           }
         }
 
+        // dev dep
+        if (pkg.name === 'pretty-format') {
+          if (dep === 'expect') {
+            return false;
+          }
+        }
+
         return true;
       })
       .map(dep =>
@@ -84,7 +91,7 @@ import {getPackages} from './buildUtils.mjs';
       assert.deepStrictEqual(
         references,
         jestDependenciesOfPackage,
-        `Expected declared references to match dependencies in packages ${
+        `Expected declared references to match dependencies in package ${
           pkg.name
         }. Got:\n\n${references.join(
           '\n',

yarn.lock

@@ -17974,6 +17974,7 @@ __metadata:
     "@types/react-test-renderer": "*"
     ansi-regex: ^5.0.1
     ansi-styles: ^5.0.0
+    expect: ^28.0.0-alpha.8
     immutable: ^4.0.0
     jest-util: ^28.0.0-alpha.8
     react: "*"