valast: feature Request: custom time.Time/datatype result generation and comparison

[kokizzu]

Background: saving to database and generating the result giving different diff because of timezone difference

minimal code to reproduce:

package foo
import "time"
import "github.com/hexops/autogold"
import "testing"
func TestFoo(t *testing.T) {
        const layout = "Jan 2, 2006 at 3:04pm (MST)"
        tm, _ := time.Parse(layout, "Feb 4, 2014 at 6:05pm (PST)")
        t2 := tm.UTC() // assuming this result queried from database from column that doesn't store timezone

        println(tm.UnixNano(), t2.UnixNano(), tm.UnixNano() == t2.UnixNano()) // both are inherently equal
       
        want := autogold.Want("internally equal", t2)
        want.Equal(t, tm)
}

it shows:

1391537100000000000 1391537100000000000 true
--- FAIL: TestFoo (0.06s)
    want.go:200: mismatch (-want +got):
        --- want
        +++ got
        @@ -1 +1,10 @@
        -time.Time{ext: 63527133900}
        \ No newline at end of file
        +time.Time{ext: 63527133900, loc: &time.Location{
        +       name: "PST",
        +       zone: []time.zone{time.zone{
        +               name: "PST",
        +       }},
        +       tx:         []time.zoneTrans{time.zoneTrans{when: -9223372036854775808}},
        +       cacheStart: -9223372036854775808,
        +       cacheEnd:   9223372036854775807,
        +       cacheZone:  &time.zone{name: "PST"},
        +}}
        \ No newline at end of file

FAIL
FAIL    command-line-arguments  0.060s
FAIL

where it inherently the same.

1. Is there a way to customize the generated struct to be using time.Unix(sec, nanosec) instead of full struct since &time.Time{ext:123} has unexported field?
2. Is there a way to customize the comparison of value so it would consider inherently equal time ignoring the timezone as equal?

[slimsag]

This is a bug in valast, which is what does the struct formatting: hexops/valast#11 (comment)

In practice, though, I suggest that when your data structures become this complex you bail out of the default formatting and instead create a simpler struct (or string) just for passing to valast.