testutil cleanup and reorg (#6658)

Prepare migrating testing auxiliary functions from tests
to testutil.

Remove local duplicates on testutil.WriteToNewTempFile().

Always favor testutil.NewTestCaseDir() over ioutil.TempDir().

Add test cases for the testing auxiliary functions.

testutil/ioutil.go

@@ -0,0 +1,46 @@
+package testutil
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/require"
+)
+
+// NewTestCaseDir creates a new temporary directory for a test case.
+// Returns the directory path and a cleanup function.
+// nolint: errcheck
+func NewTestCaseDir(t testing.TB) (string, func()) {
+	dir, err := ioutil.TempDir("", t.Name()+"_")
+	require.NoError(t, err)
+	return dir, func() { os.RemoveAll(dir) }
+}
+
+// ApplyMockIO replaces stdin/out/err with buffers that can be used during testing.
+func ApplyMockIO(c *cobra.Command) (*strings.Reader, *bytes.Buffer, *bytes.Buffer) {
+	mockIn := strings.NewReader("")
+	mockOut := bytes.NewBufferString("")
+	mockErr := bytes.NewBufferString("")
+	c.SetIn(mockIn)
+	c.SetOut(mockOut)
+	c.SetErr(mockErr)
+	return mockIn, mockOut, mockErr
+}
+
+// Write the given string to a new temporary file.
+// Returns an open file and a clean up function that
+// the caller must call to remove the file when it is
+// no longer needed.
+func WriteToNewTempFile(t testing.TB, s string) (*os.File, func()) {
+	fp, err := ioutil.TempFile("", t.Name()+"_")
+	require.Nil(t, err)
+
+	_, err = fp.WriteString(s)
+	require.Nil(t, err)
+
+	return fp, func() { os.Remove(fp.Name()) }
+}

testutil/ioutil_test.go

@@ -0,0 +1,55 @@
+package testutil_test
+
+import (
+	"io/ioutil"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/require"
+
+	"github.com/cosmos/cosmos-sdk/testutil"
+)
+
+func TestNewTestCaseDir(t *testing.T) {
+	dir1, cleanup1 := testutil.NewTestCaseDir(t)
+	dir2, cleanup2 := testutil.NewTestCaseDir(t)
+
+	require.NotEqual(t, dir1, dir2)
+	require.DirExists(t, dir1)
+	require.DirExists(t, dir2)
+
+	cleanup1()
+
+	require.NoDirExists(t, dir1)
+	require.DirExists(t, dir2)
+
+	cleanup2()
+	require.NoDirExists(t, dir2)
+}
+
+func TestApplyMockIO(t *testing.T) {
+	cmd := &cobra.Command{}
+
+	oldStdin := cmd.InOrStdin()
+	oldStdout := cmd.OutOrStdout()
+	oldStderr := cmd.ErrOrStderr()
+
+	testutil.ApplyMockIO(cmd)
+
+	require.NotEqual(t, cmd.InOrStdin(), oldStdin)
+	require.NotEqual(t, cmd.OutOrStdout(), oldStdout)
+	require.NotEqual(t, cmd.ErrOrStderr(), oldStderr)
+}
+
+func TestWriteToNewTempFile(t *testing.T) {
+	tempfile, cleanup := testutil.WriteToNewTempFile(t, "test string")
+	tempfile.Close()
+
+	bs, err := ioutil.ReadFile(tempfile.Name())
+	require.NoError(t, err)
+	require.Equal(t, "test string", string(bs))
+
+	cleanup()
+
+	require.NoFileExists(t, tempfile.Name())
+}

testutil/known_values.go

@@ -0,0 +1,6 @@
+package testutil
+
+const (
+	// Tests expect a ledger device initialized to the following mnemonic
+	TestMnemonic = "equip will roof matter pink blind book anxiety banner elbow sun young"
+)

testutil/network/doc.go

@@ -1,14 +1,14 @@
 /*
-Package testutil implements and exposes a fully operational in-process Tendermint
+Package network implements and exposes a fully operational in-process Tendermint
 test network that consists of at least one or potentially many validators. This
 test network can be used primarily for integration tests or unit test suites.
 
-The testnetwork utilizes SimApp as the ABCI application and uses all the modules
+The test network utilizes SimApp as the ABCI application and uses all the modules
 defined in the Cosmos SDK. An in-process test network can be configured with any
 number of validators as well as account funds and even custom genesis state.
 
 When creating a test network, a series of Validator objects are returned. Each
-Validator object has useful information such as their address and pubkey. A
+Validator object has useful information such as their address and public key. A
 Validator will also provide its RPC, P2P, and API addresses that can be useful
 for integration testing. In addition, a Tendermint local RPC client is also provided
 which can be handy for making direct RPC calls to Tendermint.
@@ -35,7 +35,7 @@ A typical testing flow might look like the following:
 		cfg.NumValidators = 1
 
 		s.cfg = cfg
-		s.network = testutil.NewTestNetwork(s.T(), cfg)
+		s.network = testutil.New(s.T(), cfg)
 
 		_, err := s.network.WaitForHeight(1)
 		s.Require().NoError(err)
@@ -62,4 +62,4 @@ A typical testing flow might look like the following:
 		suite.Run(t, new(IntegrationTestSuite))
 	}
 */
-package testutil
+package network

testutil/network/network.go

@@ -1,4 +1,4 @@
-package testutil
+package network
 
 import (
 	"bufio"
@@ -144,7 +144,7 @@ type (
 	}
 )
 
-func NewTestNetwork(t *testing.T, cfg Config) *Network {
+func New(t *testing.T, cfg Config) *Network {
 	// only one caller/test can create and use a network at a time
 	t.Log("acquiring test network lock")
 	lock.Lock()

testutil/network/network_test.go

@@ -1,22 +1,24 @@
-package testutil
+package network_test
 
 import (
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/suite"
+
+	"github.com/cosmos/cosmos-sdk/testutil/network"
 )
 
 type IntegrationTestSuite struct {
 	suite.Suite
 
-	network *Network
+	network *network.Network
 }
 
 func (s *IntegrationTestSuite) SetupSuite() {
 	s.T().Log("setting up integration test suite")
 
-	s.network = NewTestNetwork(s.T(), DefaultConfig())
+	s.network = network.New(s.T(), network.DefaultConfig())
 	s.Require().NotNil(s.network)
 
 	_, err := s.network.WaitForHeight(1)

testutil/network/util.go

@@ -1,4 +1,4 @@
-package testutil
+package network
 
 import (
 	"path/filepath"