go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/lucicfg/cli/base/errors.go (about)

     1  // Copyright 2019 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package base
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"go.chromium.org/luci/auth"
    21  	"go.chromium.org/luci/common/errors"
    22  
    23  	"go.chromium.org/luci/lucicfg"
    24  )
    25  
    26  // CollectErrorMessages traverses err (which can be a MultiError, recursively),
    27  // and appends all error messages there to 'in', returning the resulting slice.
    28  //
    29  // They are eventually used in JSON output and printed to stderr.
    30  func CollectErrorMessages(err error, in []string) (out []string) {
    31  	out = in
    32  	if err == nil {
    33  		return
    34  	}
    35  
    36  	if err == auth.ErrLoginRequired {
    37  		out = append(out, "Need to login first by running:\nlucicfg auth-login")
    38  		return
    39  	}
    40  
    41  	switch e := err.(type) {
    42  	case lucicfg.BacktracableError:
    43  		out = append(out, e.Backtrace())
    44  	case errors.MultiError:
    45  		for _, inner := range e {
    46  			out = CollectErrorMessages(inner, out)
    47  		}
    48  	default:
    49  		out = append(out, fmt.Sprintf("Error: %s", err))
    50  	}
    51  	return
    52  }