Added ProbeError type for use within Hermes.

hermes/probe/error/error.go

@@ -0,0 +1,71 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Author: Evan Spendlove, GitHub: evanSpendlove.
+//
+// Error implements the ProbeError used in Hermes for recording the
+// exit status of functions.
+
+// Package error defines the ProbeError used in Hermes for recording the
+// exit status of functions.
+package error
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/googleinterns/step224-2020/hermes/probe/metrics"
+)
+
+// ProbeError is an error that includes an exit status for used within Hermes.
+type ProbeError struct {
+	// TODO(evanSpendlove): Refactor metrics.ExitStatus to use something similar to metrics.APICallStatus.
+	Status metrics.ExitStatus
+	Err    error
+}
+
+// New returns a new ProbeError containing the error passed
+// with additional context.and the status.
+// Arguments:
+//	- status: pass the exit status associated with this error.
+//	- innner: pass the inner error to be wrapped.
+// Returns:
+//	- ProbeError: returns a new ProbeError object containing the args passed.
+func New(status metrics.ExitStatus, inner error) *ProbeError {
+	return &ProbeError{
+		Status: status,
+		Err:    inner,
+	}
+}
+
+// Error returns the error string from the error.
+// Returns:
+//	- string: returns the error as a string.
+func (e *ProbeError) Error() string {
+	return fmt.Sprintf("%v: %v", e.Status, e.Err)
+}
+
+// Is returns true if the argument matches this object.
+// Each error that is wrapped is examined to find a match.
+// Arguments:
+//	- target: pass the error to be compared with.
+// Returns:
+//	- bool: true if a match, else false.
+func (e *ProbeError) Is(target error) bool {
+	t, ok := target.(*ProbeError)
+	if !ok {
+		return false
+	}
+	return (e.Status == t.Status) && (errors.Is(e.Err, t.Err))
+}