mirror of https://github.com/prometheus/prometheus
82 lines
2.1 KiB
Go
82 lines
2.1 KiB
Go
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// Copyright 2015 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package promql
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import (
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"fmt"
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"math"
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"testing"
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"github.com/stretchr/testify/require"
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)
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func TestKahanSumInc(t *testing.T) {
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testCases := map[string]struct {
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first float64
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second float64
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expected float64
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}{
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"+Inf + anything = +Inf": {
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first: math.Inf(1),
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second: 2.0,
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expected: math.Inf(1),
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},
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"-Inf + anything = -Inf": {
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first: math.Inf(-1),
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second: 2.0,
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expected: math.Inf(-1),
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},
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"+Inf + -Inf = NaN": {
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first: math.Inf(1),
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second: math.Inf(-1),
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expected: math.NaN(),
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},
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"NaN + anything = NaN": {
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first: math.NaN(),
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second: 2,
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expected: math.NaN(),
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},
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"NaN + Inf = NaN": {
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first: math.NaN(),
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second: math.Inf(1),
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expected: math.NaN(),
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},
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"NaN + -Inf = NaN": {
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first: math.NaN(),
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second: math.Inf(-1),
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expected: math.NaN(),
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},
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}
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runTest := func(t *testing.T, a, b, expected float64) {
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t.Run(fmt.Sprintf("%v + %v = %v", a, b, expected), func(t *testing.T) {
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sum, c := kahanSumInc(b, a, 0)
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result := sum + c
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if math.IsNaN(expected) {
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require.Truef(t, math.IsNaN(result), "expected result to be NaN, but got %v (from %v + %v)", result, sum, c)
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} else {
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require.Equalf(t, expected, result, "expected result to be %v, but got %v (from %v + %v)", expected, result, sum, c)
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}
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})
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}
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for name, testCase := range testCases {
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t.Run(name, func(t *testing.T) {
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runTest(t, testCase.first, testCase.second, testCase.expected)
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runTest(t, testCase.second, testCase.first, testCase.expected)
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})
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}
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}
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