github.com/oskarth/go-ethereum@v1.6.8-0.20191013093314-dac24a9d3494/swarm/multihash/multihash_test.go (about)

     1  // Copyright 2018 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package multihash
    18  
    19  import (
    20  	"bytes"
    21  	"math/rand"
    22  	"testing"
    23  )
    24  
    25  // parse multihash, and check that invalid multihashes fail
    26  func TestCheckMultihash(t *testing.T) {
    27  	hashbytes := make([]byte, 32)
    28  	c, err := rand.Read(hashbytes)
    29  	if err != nil {
    30  		t.Fatal(err)
    31  	} else if c < 32 {
    32  		t.Fatal("short read")
    33  	}
    34  
    35  	expected := ToMultihash(hashbytes)
    36  
    37  	l, hl, _ := GetMultihashLength(expected)
    38  	if l != 32 {
    39  		t.Fatalf("expected length %d, got %d", 32, l)
    40  	} else if hl != 2 {
    41  		t.Fatalf("expected header length %d, got %d", 2, hl)
    42  	}
    43  	if _, _, err := GetMultihashLength(expected[1:]); err == nil {
    44  		t.Fatal("expected failure on corrupt header")
    45  	}
    46  	if _, _, err := GetMultihashLength(expected[:len(expected)-2]); err == nil {
    47  		t.Fatal("expected failure on short content")
    48  	}
    49  	dh, _ := FromMultihash(expected)
    50  	if !bytes.Equal(dh, hashbytes) {
    51  		t.Fatalf("expected content hash %x, got %x", hashbytes, dh)
    52  	}
    53  }