cosmos-sdk/testutil/collections.go

76 lines
1.8 KiB
Go

package testutil
import (
"crypto/sha256"
"encoding/hex"
"fmt"
storetypes "cosmossdk.io/store/types"
sdk "github.com/cosmos/cosmos-sdk/types"
)
// DiffCollectionsMigration is meant to aid in the migration from the previous store
// solution to collections. It takes a few steps to use it:
// 1. Write a test function that writes elements using the old store solution.
// 2. Run the test function and copy the hash that it outputs (run it a couple
// of times to make sure no non-deterministic data is being used).
// 3. Change the code to use collections and run the test function again to make
// sure the hash didn't change.
//
// First we write it as such:
//
// func TestMigrateStore(t *testing.T) {
// DiffCollectionsMigration(
// ctx,
// storeKey,
// 100,
// func(i int64) {
// err := SetPreviousProposerConsAddr(ctx, addrs[i])
// require.NoError(t, err)
// },
// "abcdef0123456789",
// )
// }
//
// Then after we change the code to use collections, we modify the writeElem function:
//
// func TestMigrateStore(t *testing.T) {
// DiffCollectionsMigration(
// ctx,
// storeKey,
// 100,
// func(i int64) {
// err := keeper.PreviousProposer.Set(ctx, addrs[i])
// require.NoError(t, err)
// },
// "abcdef0123456789",
// )
// }
func DiffCollectionsMigration(
ctx sdk.Context,
storeKey *storetypes.KVStoreKey,
iterations int,
writeElem func(int64),
targetHash string,
) error {
for i := int64(0); i < int64(iterations); i++ {
writeElem(i)
}
h := sha256.New()
it := ctx.KVStore(storeKey).Iterator(nil, nil)
defer it.Close()
for ; it.Valid(); it.Next() {
h.Write(it.Key())
h.Write(it.Value())
}
hash := h.Sum(nil)
if hex.EncodeToString(hash) != targetHash {
return fmt.Errorf("hashes don't match: %s != %s", hex.EncodeToString(hash), targetHash)
}
return nil
}