Fix issue #1662 (comparing infs should fail)

Author: ybrustin

assert/assertions.go

@@ -1527,6 +1527,9 @@ func InEpsilon(t TestingT, expected, actual interface{}, epsilon float64, msgAnd
 if err != nil {
 return Fail(t, err.Error(), msgAndArgs...)
 }
+if math.IsNaN(actualEpsilon) {
+return Fail(t, "relative error is NaN", msgAndArgs...)
+}
 if actualEpsilon > epsilon {
 return Fail(t, fmt.Sprintf("Relative error is too high: %#v (expected)\n"+
 " < %#v (actual)", epsilon, actualEpsilon), msgAndArgs...)

assert/assertions_test.go

@@ -1986,6 +1986,14 @@ func TestInEpsilon(t *testing.T) {
 {math.NaN(), 0, 1},
 {0, math.NaN(), 1},
 {0, 0, math.NaN()},
+{math.Inf(1), 1, 1},
+{math.Inf(-1), 1, 1},
+{1, math.Inf(1), 1},
+{1, math.Inf(-1), 1},
+{math.Inf(1), math.Inf(1), 1},
+{math.Inf(1), math.Inf(-1), 1},
+{math.Inf(-1), math.Inf(1), 1},
+{math.Inf(-1), math.Inf(-1), 1},
 }
 
 for _, tc := range cases {