Merge pull request #1483 from stretchr/fix-1231-InEpsilonSlice-expected-actual-order

assert.InEpsilonSlice: fix expected/actual order and other improvements

assert/assertions.go

@@ -1457,19 +1457,26 @@ func InEpsilonSlice(t TestingT, expected, actual interface{}, epsilon float64, m
 	if h, ok := t.(tHelper); ok {
 		h.Helper()
 	}
-	if expected == nil || actual == nil ||
-		reflect.TypeOf(actual).Kind() != reflect.Slice ||
-		reflect.TypeOf(expected).Kind() != reflect.Slice {
+
+	if expected == nil || actual == nil {
 		return Fail(t, "Parameters must be slice", msgAndArgs...)
 	}
 
-	actualSlice := reflect.ValueOf(actual)
 	expectedSlice := reflect.ValueOf(expected)
+	actualSlice := reflect.ValueOf(actual)
 
-	for i := 0; i < actualSlice.Len(); i++ {
-		result := InEpsilon(t, actualSlice.Index(i).Interface(), expectedSlice.Index(i).Interface(), epsilon)
-		if !result {
-			return result
+	if expectedSlice.Type().Kind() != reflect.Slice {
+		return Fail(t, "Expected value must be slice", msgAndArgs...)
+	}
+
+	expectedLen := expectedSlice.Len()
+	if !IsType(t, expected, actual) || !Len(t, actual, expectedLen) {
+		return false
+	}
+
+	for i := 0; i < expectedLen; i++ {
+		if !InEpsilon(t, expectedSlice.Index(i).Interface(), actualSlice.Index(i).Interface(), epsilon, "at index %d", i) {
+			return false
 		}
 	}