refactor: Improve isArray diff

src/matchers/is-array.spec.ts

@@ -69,6 +69,16 @@ describe('isArray', () => {
       actual: '42 (number)',
     });
 
+    expect(isArray().getDiff({ foo: 'bar' })).toEqual({
+      expected: 'array',
+      actual: '{"foo": "bar"} (object)',
+    });
+
+    expect(isArray([1, 2]).getDiff(42)).toEqual({
+      expected: 'array containing [1, 2]',
+      actual: 42,
+    });
+
     expect(isArray([1, 2]).getDiff([2])).toEqual({
       expected: 'array containing [1, 2]',
       actual: [2],

src/matchers/is-array.ts

@@ -1,4 +1,6 @@
 import { printExpected } from 'jest-matcher-utils';
+import stripAnsi from 'strip-ansi';
+import { printArg } from '../print';
 import { deepEquals } from './deep-equals';
 import type { TypeMatcher } from './matcher';
 import { isMatcher, matches } from './matcher';
@@ -49,13 +51,6 @@ export const isArray = <T extends unknown[]>(containing?: T): TypeMatcher<T> =>
       toJSON: () =>
         containing ? `array(${printExpected(containing)})` : 'array',
       getDiff: (actual) => {
-        if (!Array.isArray(actual)) {
-          return {
-            actual: `${actual} (${typeof actual})`,
-            expected: 'array',
-          };
-        }
-
         if (containing) {
           return {
             actual,
@@ -72,7 +67,7 @@ export const isArray = <T extends unknown[]>(containing?: T): TypeMatcher<T> =>
         }
 
         return {
-          actual,
+          actual: `${stripAnsi(printArg(actual, true))} (${typeof actual})`,
           expected: 'array',
         };
       },

src/print.ts

@@ -21,7 +21,7 @@ export const printProperty = (property: Property) => {
   return `.${property}`;
 };
 
-const printArg = (arg: unknown, received = false): string => {
+export const printArg = (arg: unknown, received = false): string => {
   // Call toJSON on matchers directly to avoid wrapping strings returned by them in quotes.
   if (isMatcher(arg)) {
     return arg.toJSON();