github.com/thiagoyeds/go-cloud@v0.26.0/docstore/drivertest/util.go (about) 1 // Copyright 2019 The Go Cloud Development Kit Authors 2 // 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 // https://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 package drivertest 16 17 import ( 18 "math/rand" 19 "sync" 20 21 "github.com/google/uuid" 22 "gocloud.dev/docstore/driver" 23 ) 24 25 // MakeUniqueStringDeterministicForTesting uses a specified seed value to 26 // produce the same sequence of values in driver.UniqueString for testing. 27 // 28 // Call when running tests that will be replayed. 29 func MakeUniqueStringDeterministicForTesting(seed int64) { 30 r := &randReader{r: rand.New(rand.NewSource(seed))} 31 uuid.SetRand(r) 32 } 33 34 type randReader struct { 35 mu sync.Mutex 36 r *rand.Rand 37 } 38 39 func (r *randReader) Read(buf []byte) (int, error) { 40 r.mu.Lock() 41 defer r.mu.Unlock() 42 return r.r.Read(buf) 43 } 44 45 // MustDocument is like driver.NewDocument, but panics on error. 46 func MustDocument(doc interface{}) driver.Document { 47 dd, err := driver.NewDocument(doc) 48 if err != nil { 49 panic(err) 50 } 51 return dd 52 }