fix(expect): improve toThrow(asymmetricMatcher) failure message

[hi-ogawa]

Description

• Closes Preserve asymmetric matcher messages #4093
• Follow up fix(expect): implement chai inspect for AsymmetricMatcher #4942

Tiny improvement for rather minor use case, but I wanted to finish off that issue.

Jest example is in the same repro as the last PR:

• https://stackblitz.com/edit/github-o6sfsk?file=tests%2Fjest.test.cjs

    Message:
      expect(received).toThrow(expected)
    
    Expected asymmetric matcher: StringNotContaining "ll"
    
    Thrown value: "hello"
    

    Difference:

    Compared values have no visual difference.Error:

      67 |
      68 | test("throw error 4", () => {
    > 69 |   expect(() => { throw "hello" }).toThrow(expect.not.stringContaining("ll"))
         |                                   ^
      70 | })

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[hi-ogawa]

I went with using #{act} (short for "actual") here since currently showDiff is false (5th argument of this.assert) and the detail is not visible to users on terminal.

Looking at the history of whether enable showDiff or not, it thought this might be a performance concern of object comparison #2828 #3582 ("concordance" might expected to fixed this, but later reverted and showDiff became false), but considering toEqual and normal assertions showing diff already, would it be okay to put this showDiff back to true (i.e. default)?

[hi-ogawa]

Hmm, I just tested showDiff: true, but diff is not showing up for this case:

 FAIL  |core| test/jest-expect.test.ts > repro
AssertionError: expected error to match asymmetric matcher
 ❯ test/jest-expect.test.ts:1080:35
    1078| 
    1079| it.only("repro", () => {
    1080|   expect(() => { throw "hello" }).toThrow(expect.stringContaining("xx"))
       |                                   ^
    1081| });
    1082| 

I'll read up more on how diff generation is decided.

[hi-ogawa]

It like this (odd) case leads to omitDifference here

vitest/packages/utils/src/diff/index.ts

Lines 85 to 88 in 9d3a7de

	expectedType = a.getExpectedType()
	// Primitive types boolean and number omit difference below.
	// For example, omit difference for expect.stringMatching(regexp)
	omitDifference = expectedType === 'string'

[hi-ogawa]

In the end, I just made showDiff true for this case toThrow(asymmetricMatcher) and the lack of error detail would be only this edge case #5000 (comment)

Please let me know if we want to adjust "message" part to cover this edge case (e.g. by using chai's "#{act} formatting) or we can leave it as is.