1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
// Copyright 2018 The Hugo Authors. All rights reserved.
//
// 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
// http://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.
// Package errors contains common Hugo errors and error related utilities.
package herrors
import (
"bufio"
"io"
"strings"
"github.com/spf13/afero"
)
// LineMatcher is used to match a line with an error.
type LineMatcher func(le FileError, lineNumber int, line string) bool
// SimpleLineMatcher matches if the current line number matches the line number
// in the error.
var SimpleLineMatcher = func(le FileError, lineNumber int, line string) bool {
return le.LineNumber() == lineNumber
}
// ErrorContext contains contextual information about an error. This will
// typically be the lines surrounding some problem in a file.
type ErrorContext struct {
// If a match will contain the matched line and up to 2 lines before and after.
// Will be empty if no match.
Lines []string
// The position of the error in the Lines above. 0 based.
Pos int
// The linenumber in the source file from where the Lines start. Starting at 1.
LineNumber int
// The lexer to use for syntax highlighting.
// https://gohugo.io/content-management/syntax-highlighting/#list-of-chroma-highlighting-languages
ChromaLexer string
}
var _ causer = (*ErrorWithFileContext)(nil)
// ErrorWithFileContext is an error with some additional file context related
// to that error.
type ErrorWithFileContext struct {
cause error
ErrorContext
}
func (e *ErrorWithFileContext) Error() string {
return e.cause.Error()
}
func (e *ErrorWithFileContext) Cause() error {
return e.cause
}
// WithFileContextForFile will try to add a file context with lines matching the given matcher.
// If no match could be found, the original error is returned with false as the second return value.
func WithFileContextForFile(e error, filename string, fs afero.Fs, chromaLexer string, matcher LineMatcher) (error, bool) {
f, err := fs.Open(filename)
if err != nil {
return e, false
}
defer f.Close()
return WithFileContext(e, f, chromaLexer, matcher)
}
// WithFileContextForFile will try to add a file context with lines matching the given matcher.
// If no match could be found, the original error is returned with false as the second return value.
func WithFileContext(e error, r io.Reader, chromaLexer string, matcher LineMatcher) (error, bool) {
if e == nil {
panic("error missing")
}
le := UnwrapFileError(e)
if le == nil {
var ok bool
if le, ok = ToFileError("bash", e).(FileError); !ok {
return e, false
}
}
errCtx := locateError(r, le, matcher)
if errCtx.LineNumber == -1 {
return e, false
}
if chromaLexer != "" {
errCtx.ChromaLexer = chromaLexer
} else {
errCtx.ChromaLexer = chromaLexerFromType(le.Type())
}
return &ErrorWithFileContext{cause: e, ErrorContext: errCtx}, true
}
// UnwrapErrorWithFileContext tries to unwrap an ErrorWithFileContext from err.
// It returns nil if this is not possible.
func UnwrapErrorWithFileContext(err error) *ErrorWithFileContext {
for err != nil {
switch v := err.(type) {
case *ErrorWithFileContext:
return v
case causer:
err = v.Cause()
default:
return nil
}
}
return nil
}
func chromaLexerFromType(fileType string) string {
return fileType
}
func locateErrorInString(le FileError, src string, matcher LineMatcher) ErrorContext {
return locateError(strings.NewReader(src), nil, matcher)
}
func locateError(r io.Reader, le FileError, matches LineMatcher) ErrorContext {
var errCtx ErrorContext
s := bufio.NewScanner(r)
lineNo := 0
var buff [6]string
i := 0
errCtx.Pos = -1
for s.Scan() {
lineNo++
txt := s.Text()
buff[i] = txt
if errCtx.Pos != -1 && i >= 5 {
break
}
if errCtx.Pos == -1 && matches(le, lineNo, txt) {
errCtx.Pos = i
errCtx.LineNumber = lineNo - i
}
if errCtx.Pos == -1 && i == 2 {
// Shift left
buff[0], buff[1] = buff[i-1], buff[i]
} else {
i++
}
}
// Go's template parser will typically report "unexpected EOF" errors on the
// empty last line that is supressed by the scanner.
// Do an explicit check for that.
if errCtx.Pos == -1 {
lineNo++
if matches(le, lineNo, "") {
buff[i] = ""
errCtx.Pos = i
errCtx.LineNumber = lineNo - 1
i++
}
}
if errCtx.Pos != -1 {
low := errCtx.Pos - 2
if low < 0 {
low = 0
}
high := i
errCtx.Lines = buff[low:high]
} else {
errCtx.Pos = -1
errCtx.LineNumber = -1
}
return errCtx
}
|
