github.com/dtroyer-salad/og2/v2@v2.0.0-20240412154159-c47231610877/internal/syncutil/merge_test.go (about)

     1  /*
     2  Copyright The ORAS Authors.
     3  Licensed under the Apache License, Version 2.0 (the "License");
     4  you may not use this file except in compliance with the License.
     5  You may obtain a copy of the License at
     6  
     7  http://www.apache.org/licenses/LICENSE-2.0
     8  
     9  Unless required by applicable law or agreed to in writing, software
    10  distributed under the License is distributed on an "AS IS" BASIS,
    11  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  See the License for the specific language governing permissions and
    13  limitations under the License.
    14  */
    15  
    16  package syncutil
    17  
    18  import (
    19  	"context"
    20  	"testing"
    21  
    22  	"golang.org/x/sync/errgroup"
    23  )
    24  
    25  func TestMerge(t *testing.T) {
    26  	var merge Merge[int]
    27  
    28  	// generate expected result
    29  	size := 100
    30  	factor := -1
    31  	var expected int
    32  	for i := 1; i < size; i++ {
    33  		expected += i * factor
    34  	}
    35  
    36  	// test merge
    37  	ctx := context.Background()
    38  	eg, _ := errgroup.WithContext(ctx)
    39  	var result int
    40  	for i := 1; i < size; i++ {
    41  		eg.Go(func(num int) func() error {
    42  			return func() error {
    43  				var f int
    44  				getFactor := func() error {
    45  					f = factor
    46  					return nil
    47  				}
    48  				calculate := func(items []int) error {
    49  					for _, item := range items {
    50  						result += item * f
    51  					}
    52  					return nil
    53  				}
    54  				return merge.Do(num, getFactor, calculate)
    55  			}
    56  		}(i))
    57  	}
    58  	if err := eg.Wait(); err != nil {
    59  		t.Errorf("Merge.Do() error = %v, wantErr %v", err, nil)
    60  	}
    61  	if result != expected {
    62  		t.Errorf("Merge.Do() = %v, want %v", result, expected)
    63  	}
    64  }