-
Notifications
You must be signed in to change notification settings - Fork 236
/
error_formatter.go
145 lines (122 loc) · 4.25 KB
/
error_formatter.go
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
/*
Copyright 2017 Google Inc. 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 jsonnet
import (
"bytes"
"fmt"
"io"
"github.com/google/go-jsonnet/ast"
"github.com/google/go-jsonnet/internal/errors"
)
// An ErrorFormatter formats errors with stacktraces and color.
type ErrorFormatter interface {
// Format static, runtime, and unexpected errors prior to printing them.
Format(err error) string
// Set the the maximum length of stack trace before cropping.
SetMaxStackTraceSize(size int)
// Set the color formatter for the location color.
SetColorFormatter(color ColorFormatter)
}
// ColorFormatter represents a function that writes to the terminal using color.
type ColorFormatter func(w io.Writer, f string, a ...interface{}) (n int, err error)
var _ ErrorFormatter = &termErrorFormatter{}
type termErrorFormatter struct {
// Examples of current state of the art.
// http://elm-lang.org/blog/compiler-errors-for-humans
// https://clang.llvm.org/diagnostics.html
color ColorFormatter
// sp is currently never set, but is used to format locations.
sp *ast.SourceProvider
// maxStackTraceSize is the maximum length of stack trace before cropping
maxStackTraceSize int
pretty bool
}
func (ef *termErrorFormatter) SetMaxStackTraceSize(size int) {
ef.maxStackTraceSize = size
}
func (ef *termErrorFormatter) SetColorFormatter(color ColorFormatter) {
ef.color = color
}
func (ef *termErrorFormatter) Format(err error) string {
switch err := err.(type) {
case RuntimeError:
return ef.formatRuntime(&err)
case errors.StaticError:
return ef.formatStatic(err)
default:
return ef.formatInternal(err)
}
}
func (ef *termErrorFormatter) formatRuntime(err *RuntimeError) string {
return err.Error() + "\n" + ef.buildStackTrace(err.StackTrace)
}
func (ef *termErrorFormatter) formatStatic(err errors.StaticError) string {
var buf bytes.Buffer
buf.WriteString(err.Error() + "\n")
ef.showCode(&buf, err.Loc())
return buf.String()
}
const bugURL = "https://github.com/google/go-jsonnet/issues"
func (ef *termErrorFormatter) formatInternal(err error) string {
return "INTERNAL ERROR: " + err.Error() + "\n" +
"Please report a bug here: " + bugURL + "\n"
}
func (ef *termErrorFormatter) showCode(buf *bytes.Buffer, loc ast.LocationRange) {
errFprintf := fmt.Fprintf
if ef.color != nil {
errFprintf = ef.color
}
if loc.WithCode() {
// TODO(sbarzowski) include line numbers
// TODO(sbarzowski) underline errors instead of depending only on color
fmt.Fprintf(buf, "\n")
beginning := ast.LineBeginning(&loc)
ending := ast.LineEnding(&loc)
fmt.Fprintf(buf, "%v", ef.sp.GetSnippet(beginning))
errFprintf(buf, "%v", ef.sp.GetSnippet(loc)) //nolint:errcheck
fmt.Fprintf(buf, "%v", ef.sp.GetSnippet(ending))
buf.WriteByte('\n')
}
fmt.Fprintf(buf, "\n")
}
func (ef *termErrorFormatter) frame(frame *TraceFrame, buf *bytes.Buffer) {
// TODO(sbarzowski) tabs are probably a bad idea
fmt.Fprintf(buf, "\t%v\t%v\n", frame.Loc.String(), frame.Name)
if ef.pretty {
ef.showCode(buf, frame.Loc)
}
}
func (ef *termErrorFormatter) buildStackTrace(frames []TraceFrame) string {
// https://github.com/google/jsonnet/blob/master/core/libjsonnet.cpp#L594
maxAbove := ef.maxStackTraceSize / 2
maxBelow := ef.maxStackTraceSize - maxAbove
var buf bytes.Buffer
sz := len(frames)
for i := 0; i < sz; i++ {
// TODO(sbarzowski) make pretty format more readable (it's already useful)
if ef.pretty {
fmt.Fprintf(&buf, "-------------------------------------------------\n")
}
if ef.maxStackTraceSize > 0 && i >= maxAbove && i < sz-maxBelow {
if ef.pretty {
fmt.Fprintf(&buf, "\t... (skipped %v frames)\n", sz-maxAbove-maxBelow)
} else {
buf.WriteString("\t...\n")
}
i = sz - maxBelow - 1
} else {
ef.frame(&frames[sz-i-1], &buf)
}
}
return buf.String()
}