Diffs on structs with nested time.Time objects produce hard to read diffs

[shawc71]

We recently observed tough to read diffs produced by testify on assertion failures on structs when the structs contain nested time.Time objects.

I have created this repo with this testfile that does a minimal repro of the issue https://github.com/shawc71/testify-issue-demo/blob/master/example_test.go, this uses the latest testify commit on master.

In summary, given a struct like:

type structWithTime struct {
            someTime   *time.Time
            someString string
}

the following produces a diff that is 1220 lines+ and unparsable for humans:

    t.Run("different tzs", func(t *testing.T) {
        expectedTime, err := time.Parse("2006-01-02", "2020-05-22")
        assert.NoError(t, err)
        expected := &structWithTime{
            someTime:   &expectedTime,
            someString: "some val",
        }

        loc, err := time.LoadLocation("America/New_York")
        assert.NoError(t, err)
        actualTime, err := time.ParseInLocation("2006-01-02", "2020-05-21", loc)
        actual := &structWithTime{
            someTime:   &actualTime,
            someString: "some val",
        }
        assert.Equal(t, expected, actual)
    })

I believe this was an unintended side-effect of https://github.com/stretchr/testify/pull/895.

This makes doing assertions on structs with time.Time pretty rough. I imagine having a time.Time in a struct and being able to do assertions on those structs is a pretty common use case so I think we should make this nicer. :)

I am working on a PR to address this :)

[shawc71]

Here's my attempt at fixing it: https://github.com/stretchr/testify/pull/1079