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