all: Tweak error creation (#6391)

- In the few places where we wrap errors, use the new Go 1.13 "%w"
  construction instead of %s or %v.

- Where we create errors with constant strings, consistently use
  errors.New and not fmt.Errorf.

- Remove capitalization from errors in the few places where we had that.

cmd/stcli/client.go

@@ -10,6 +10,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"net"
 	"net/http"
@@ -80,16 +81,16 @@ func (c *APIClient) Post(url, body string) (*http.Response, error) {
 
 func checkResponse(response *http.Response) error {
 	if response.StatusCode == 404 {
-		return fmt.Errorf("Invalid endpoint or API call")
+		return errors.New("invalid endpoint or API call")
 	} else if response.StatusCode == 403 {
-		return fmt.Errorf("Invalid API key")
+		return errors.New("invalid API key")
 	} else if response.StatusCode != 200 {
 		data, err := responseToBArray(response)
 		if err != nil {
 			return err
 		}
 		body := strings.TrimSpace(string(data))
-		return fmt.Errorf("Unexpected HTTP status returned: %s\n%s", response.Status, body)
+		return fmt.Errorf("unexpected HTTP status returned: %s\n%s", response.Status, body)
 	}
 	return nil
 }

cmd/stcli/errors.go

@@ -7,6 +7,7 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
@@ -54,7 +55,7 @@ func errorsPush(c *cli.Context) error {
 		if body != "" {
 			errStr += "\nBody: " + body
 		}
-		return fmt.Errorf(errStr)
+		return errors.New(errStr)
 	}
 	return nil
 }

cmd/stcompdirs/main.go

@@ -60,7 +60,7 @@ func compareDirectories(dirs ...string) error {
 				} else if res[i].name > res[0].name {
 					return fmt.Errorf("%s missing %v (present in %s)", dirs[i], res[0], dirs[0])
 				}
-				return fmt.Errorf("Mismatch; %v (%s) != %v (%s)", res[i], dirs[i], res[0], dirs[0])
+				return fmt.Errorf("mismatch; %v (%s) != %v (%s)", res[i], dirs[i], res[0], dirs[0])
 			}
 		}
 

cmd/strelaypoolsrv/main.go

@@ -10,6 +10,7 @@ import (
 	"context"
 	"crypto/tls"
 	"encoding/json"
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -494,7 +495,7 @@ func handleRelayTest(request request) {
 		if debug {
 			log.Println("Test for relay", request.relay, "failed")
 		}
-		request.result <- result{fmt.Errorf("connection test failed"), 0}
+		request.result <- result{errors.New("connection test failed"), 0}
 		return
 	}
 

cmd/stvanity/main.go

@@ -14,6 +14,7 @@ import (
 	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/pem"
+	"errors"
 	"flag"
 	"fmt"
 	"math/big"
@@ -191,7 +192,7 @@ func pemBlockForKey(priv interface{}) (*pem.Block, error) {
 		}
 		return &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}, nil
 	default:
-		return nil, fmt.Errorf("unknown key type")
+		return nil, errors.New("unknown key type")
 	}
 }
 

cmd/ursrv/main.go

@@ -266,10 +266,10 @@ type report struct {
 
 func (r *report) Validate() error {
 	if r.UniqueID == "" || r.Version == "" || r.Platform == "" {
-		return fmt.Errorf("missing required field")
+		return errors.New("missing required field")
 	}
 	if len(r.Date) != 8 {
-		return fmt.Errorf("date not initialized")
+		return errors.New("date not initialized")
 	}
 
 	// Some fields may not be null.