[FAB-1535]Cleanup several pycharm warnings

https://jira.hyperledger.org/browse/FAB-1535

Some warings are reported by pycharm IDE, this commit
fixs warnings. Specific warnings list in JIRA ticket.

Change-Id: I122ea6627627893e74227580468309e31a5d47e3
Signed-off-by: grapebaba <281165273@qq.com>

core/chaincode/platforms/car/hash.go

@@ -21,6 +21,8 @@ import (
 	"fmt"
 	"io/ioutil"
 
+	"errors"
+
 	"github.com/golang/protobuf/proto"
 	"github.com/hyperledger/fabric/core/util"
 	pb "github.com/hyperledger/fabric/protos/peer"
@@ -36,7 +38,7 @@ func generateHashcode(spec *pb.ChaincodeSpec, path string) (string, error) {
 
 	ctor := spec.CtorMsg
 	if ctor == nil || len(ctor.Args) == 0 {
-		return "", fmt.Errorf("Cannot generate hashcode from empty ctor")
+		return "", errors.New("Cannot generate hashcode from empty ctor")
 	}
 	ctorbytes, err := proto.Marshal(ctor)
 	if err != nil {

core/chaincode/platforms/car/test/car_test.go

@@ -35,22 +35,19 @@ func TestCar_BuildImage(t *testing.T) {
 	vm, err := container.NewVM()
 
 	if err != nil {
-		t.Fail()
-		t.Logf("Error getting VM: %s", err)
+		t.Errorf("Error getting VM: %s", err)
 		return
 	}
 	// Build the spec
 	cwd, err := os.Getwd()
 	if err != nil {
-		t.Fail()
-		t.Logf("Error getting CWD: %s", err)
+		t.Errorf("Error getting CWD: %s", err)
 		return
 	}
 
 	chaincodePath := cwd + "/org.hyperledger.chaincode.example02-0.1-SNAPSHOT.car"
 	spec := &pb.ChaincodeSpec{Type: pb.ChaincodeSpec_CAR, ChaincodeID: &pb.ChaincodeID{Name: "cartest", Path: chaincodePath}, CtorMsg: &pb.ChaincodeInput{Args: util.ToChaincodeArgs("f")}}
 	if _, err := vm.BuildChaincodeContainer(spec); err != nil {
-		t.Fail()
-		t.Log(err)
+		t.Error(err)
 	}
 }

core/chaincode/platforms/golang/hash.go

@@ -58,7 +58,7 @@ func getCodeFromHTTP(path string) (codegopath string, err error) {
 		}
 	}
 	if origgopath == "" {
-		err = fmt.Errorf("GOPATH not defined")
+		err = errors.New("GOPATH not defined")
 		return
 	}
 	// Only take the first element of GOPATH
@@ -126,7 +126,7 @@ func getCodeFromFS(path string) (codegopath string, err error) {
 	logger.Debugf("getCodeFromFS %s", path)
 	gopath := os.Getenv("GOPATH")
 	if gopath == "" {
-		err = fmt.Errorf("GOPATH not defined")
+		err = errors.New("GOPATH not defined")
 		return
 	}
 	// Only take the first element of GOPATH
@@ -143,17 +143,17 @@ func getCodeFromFS(path string) (codegopath string, err error) {
 //with the same (name, ctor, args)
 func collectChaincodeFiles(spec *pb.ChaincodeSpec, tw *tar.Writer) (string, error) {
 	if spec == nil {
-		return "", fmt.Errorf("Cannot collect files from nil spec")
+		return "", errors.New("Cannot collect files from nil spec")
 	}
 
 	chaincodeID := spec.ChaincodeID
 	if chaincodeID == nil || chaincodeID.Path == "" {
-		return "", fmt.Errorf("Cannot collect files from empty chaincode path")
+		return "", errors.New("Cannot collect files from empty chaincode path")
 	}
 
 	ctor := spec.CtorMsg
 	if ctor == nil || len(ctor.Args) == 0 {
-		return "", fmt.Errorf("Cannot collect files from empty ctor")
+		return "", errors.New("Cannot collect files from empty ctor")
 	}
 
 	//code root will point to the directory where the code exists

core/chaincode/platforms/golang/package.go

@@ -24,6 +24,8 @@ import (
 
 	"github.com/spf13/viper"
 
+	"errors"
+
 	cutil "github.com/hyperledger/fabric/core/container/util"
 	pb "github.com/hyperledger/fabric/protos/peer"
 )
@@ -42,7 +44,7 @@ func writeChaincodePackage(spec *pb.ChaincodeSpec, tw *tar.Writer) error {
 	}
 
 	if urlLocation == "" {
-		return fmt.Errorf("empty url location")
+		return errors.New("ChaincodeSpec's path/URL cannot be empty")
 	}
 
 	if strings.LastIndex(urlLocation, "/") == len(urlLocation)-1 {

core/chaincode/platforms/golang/platform.go

@@ -44,15 +44,15 @@ func pathExists(path string) (bool, error) {
 
 // ValidateSpec validates Go chaincodes
 func (goPlatform *Platform) ValidateSpec(spec *pb.ChaincodeSpec) error {
-	url, err := url.Parse(spec.ChaincodeID.Path)
-	if err != nil || url == nil {
+	path, err := url.Parse(spec.ChaincodeID.Path)
+	if err != nil || path == nil {
 		return fmt.Errorf("invalid path: %s", err)
 	}
 
 	//we have no real good way of checking existence of remote urls except by downloading and testin
 	//which we do later anyway. But we *can* - and *should* - test for existence of local paths.
 	//Treat empty scheme as a local filesystem path
-	if url.Scheme == "" {
+	if path.Scheme == "" {
 		gopath := os.Getenv("GOPATH")
 		// Only take the first element of GOPATH
 		gopath = filepath.SplitList(gopath)[0]

core/chaincode/platforms/java/hash.go

@@ -26,6 +26,8 @@ import (
 	"os/exec"
 	"strings"
 
+	"errors"
+
 	"github.com/golang/protobuf/proto"
 	ccutil "github.com/hyperledger/fabric/core/chaincode/platforms/util"
 	"github.com/hyperledger/fabric/core/util"
@@ -34,22 +36,21 @@ import (
 
 func getCodeFromHTTP(path string) (codegopath string, err error) {
 
-	var tmp string
-	tmp, err = ioutil.TempDir("", "javachaincode")
+	codegopath, err = ioutil.TempDir("", "javachaincode")
 
 	if err != nil {
 		return "", fmt.Errorf("Error creating temporary file: %s", err)
 	}
 	var out bytes.Buffer
 
-	cmd := exec.Command("git", "clone", path, tmp)
+	cmd := exec.Command("git", "clone", path, codegopath)
 	cmd.Stderr = &out
 	cmderr := cmd.Run()
 	if cmderr != nil {
 		return "", fmt.Errorf("Error cloning git repository %s", cmderr)
 	}
 
-	return tmp, nil
+	return codegopath, nil
 
 }
 
@@ -61,17 +62,17 @@ func getCodeFromHTTP(path string) (codegopath string, err error) {
 //with the same (name, ctor, args)
 func collectChaincodeFiles(spec *pb.ChaincodeSpec, tw *tar.Writer) (string, error) {
 	if spec == nil {
-		return "", fmt.Errorf("Cannot collect chaincode files from nil spec")
+		return "", errors.New("Cannot collect chaincode files from nil spec")
 	}
 
 	chaincodeID := spec.ChaincodeID
 	if chaincodeID == nil || chaincodeID.Path == "" {
-		return "", fmt.Errorf("Cannot collect chaincode files from empty chaincode path")
+		return "", errors.New("Cannot collect chaincode files from empty chaincode path")
 	}
 
 	ctor := spec.CtorMsg
 	if ctor == nil || len(ctor.Args) == 0 {
-		return "", fmt.Errorf("Cannot collect chaincode files from empty ctor")
+		return "", errors.New("Cannot collect chaincode files from empty ctor")
 	}
 
 	codepath := chaincodeID.Path

core/chaincode/platforms/java/package.go

@@ -25,6 +25,8 @@ import (
 
 	"os"
 
+	"errors"
+
 	cutil "github.com/hyperledger/fabric/core/container/util"
 	pb "github.com/hyperledger/fabric/protos/peer"
 	"github.com/spf13/viper"
@@ -35,7 +37,7 @@ var buildCmd = map[string]string{
 	"pom.xml":      "mvn -f pom.xml clean && mvn -f pom.xml package",
 }
 
-//return the type of build gradle/maven based on the file
+//getBuildCmd returns the type of build gradle/maven based on the file
 //found in java chaincode project root
 //build.gradle - gradle  - returns the first found build type
 //pom.xml - maven
@@ -51,7 +53,7 @@ func getBuildCmd(packagePath string) (string, error) {
 				}
 			}
 		}
-		return "", fmt.Errorf("Build file not found")
+		return "", errors.New("Build file not found")
 	}
 }
 
@@ -77,7 +79,7 @@ func writeChaincodePackage(spec *pb.ChaincodeSpec, tw *tar.Writer) error {
 	}
 
 	if urlLocation == "" {
-		return fmt.Errorf("empty url location")
+		return errors.New("ChaincodeSpec's path/URL cannot be empty")
 	}
 
 	if strings.LastIndex(urlLocation, "/") == len(urlLocation)-1 {

core/chaincode/platforms/java/platform.go

@@ -31,8 +31,8 @@ type Platform struct {
 
 //ValidateSpec validates the java chaincode specs
 func (javaPlatform *Platform) ValidateSpec(spec *pb.ChaincodeSpec) error {
-	url, err := url.Parse(spec.ChaincodeID.Path)
-	if err != nil || url == nil {
+	path, err := url.Parse(spec.ChaincodeID.Path)
+	if err != nil || path == nil {
 		return fmt.Errorf("invalid path: %s", err)
 	}