feat(config): add a typed error on config file not found (#264)

Author: jerome-quere

scw/config.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"syscall"
 	"text/template"
 
 	"github.com/scaleway/scaleway-sdk-go/internal/auth"
@@ -170,6 +171,9 @@ func LoadConfigFromPath(path string) (*Config, error) {
 
 	file, err := ioutil.ReadFile(path)
 	if err != nil {
+		if pathError, isPathError := err.(*os.PathError); isPathError && pathError.Err == syscall.ENOENT {
+			return nil, configFileNotFound(pathError.Path)
+		}
 		return nil, errors.Wrap(err, "cannot read config file")
 	}
 

scw/config_test.go

@@ -265,7 +265,7 @@ func TestLoadProfileAndActiveProfile(t *testing.T) {
 		},
 		{
 			name:          "No config",
-			expectedError: "scaleway-sdk-go: cannot read config file: open {HOME}/.config/scw/config.yaml: no such file or directory",
+			expectedError: "scaleway-sdk-go: cannot read config file {HOME}/.config/scw/config.yaml: no such file or directory",
 			env: map[string]string{
 				"HOME": "{HOME}",
 			},

scw/errors.go

@@ -270,3 +270,18 @@ func (e InvalidClientOptionError) IsScwSdkError() {}
 func (e InvalidClientOptionError) Error() string {
 	return fmt.Sprintf("scaleway-sdk-go: %s", e.errorType)
 }
+
+// ConfigFileNotFound indicates that the config file could not be found
+type ConfigFileNotFoundError struct {
+	path string
+}
+
+func configFileNotFound(path string) *ConfigFileNotFoundError {
+	return &ConfigFileNotFoundError{path: path}
+}
+
+// ConfigFileNotFoundError implements the SdkError interface
+func (e ConfigFileNotFoundError) IsScwSdkError() {}
+func (e ConfigFileNotFoundError) Error() string {
+	return fmt.Sprintf("scaleway-sdk-go: cannot read config file %s: no such file or directory", e.path)
+}

scw/load_config_test.go

@@ -102,7 +102,7 @@ func TestLoad(t *testing.T) {
 			env: map[string]string{
 				scwConfigPathEnv: "{HOME}/fake/test.conf",
 			},
-			expectedError: "scaleway-sdk-go: cannot read config file: open {HOME}/fake/test.conf: no such file or directory",
+			expectedError: "scaleway-sdk-go: cannot read config file {HOME}/fake/test.conf: no such file or directory",
 		},
 		{
 			name: "Err: custom-path config with invalid V2",