test Quo edge cases

gistfile1.txt

func TestEdgeCases(t *testing.T) {
	one := mustV(NewDecFromString("1"))
	zero := mustV(NewDecFromString("0"))
	NaN := mustV(NewDecFromString("NaN"))
	big := NewDecFinite(math.MaxInt64, 100_000-1)
	small := NewDecFinite(1,  -100_000)
	specs := map[string]struct {
		a, b   Dec
		expVal Dec
		expErr bool
	}{
		"div by 0": {
			a: one, b: zero, expErr: true,
		},
		"div by Nan": {
			a: one, b: NaN, expErr: true,
		},
		"out of precision range - after comma": {
			a: one, b: NewDecFinite(1, 35), expErr: true,
		},
		"out of precision range - before comma": {
			a: NewDecFinite(1, 34), b: NewDecFinite(1, -1), expErr: true,
		},
		"-1/-1=1": {
			a: NewDecFromInt64(-1), b: NewDecFromInt64(-1), expVal: NewDecFromInt64(1),
		},
		"-1/1=-1": {
			a: NewDecFromInt64(-1), b: NewDecFromInt64(1), expVal: NewDecFromInt64(-1),
		},
		"1/-1=-1": {
			a: NewDecFromInt64(1), b: NewDecFromInt64(-1), expVal: NewDecFromInt64(-1),
		},
		"equal with trailing zeros": {
			a: mustV(NewDecFromString("0.10000")), b: NewDecFromInt64(1), expVal: mustV(NewDecFromString("0.1")),
		},
		"big/big":{
			a: big, b: big, expVal: one,
		},
		"small/small":{
			a: small, b: small, expVal: one,
		},
		"exceed max exponent":{
			a: big, b: mustV(NewDecFromString("0.1")), expErr: true,
		},
		"exceed min exponent":{
			a: small, b: mustV(NewDecFromString("10")), expErr: true,
		},
	}
	for name, spec := range specs {
		t.Run(name, func(t *testing.T) {
			gotV, gotErr := spec.a.Quo(spec.b)
			if spec.expErr {
				require.Error(t, gotErr, gotV)
				return
			}
			require.NoError(t, gotErr, gotV)
			require.True(t, spec.expVal.Equal(gotV)) // not same but equal
		})
	}

}

func mustV[T any](v T, err error) T {
	if err != nil {
		panic(err)
	}
	return v
}