peridot/vendor/github.com/pelletier/go-toml/v2/errors.go
2024-10-16 12:56:53 +02:00

253 lines
5.9 KiB
Go

package toml
import (
"fmt"
"strconv"
"strings"
"github.com/pelletier/go-toml/v2/internal/danger"
"github.com/pelletier/go-toml/v2/unstable"
)
// DecodeError represents an error encountered during the parsing or decoding
// of a TOML document.
//
// In addition to the error message, it contains the position in the document
// where it happened, as well as a human-readable representation that shows
// where the error occurred in the document.
type DecodeError struct {
message string
line int
column int
key Key
human string
}
// StrictMissingError occurs in a TOML document that does not have a
// corresponding field in the target value. It contains all the missing fields
// in Errors.
//
// Emitted by Decoder when DisallowUnknownFields() was called.
type StrictMissingError struct {
// One error per field that could not be found.
Errors []DecodeError
}
// Error returns the canonical string for this error.
func (s *StrictMissingError) Error() string {
return "strict mode: fields in the document are missing in the target struct"
}
// String returns a human readable description of all errors.
func (s *StrictMissingError) String() string {
var buf strings.Builder
for i, e := range s.Errors {
if i > 0 {
buf.WriteString("\n---\n")
}
buf.WriteString(e.String())
}
return buf.String()
}
type Key []string
// Error returns the error message contained in the DecodeError.
func (e *DecodeError) Error() string {
return "toml: " + e.message
}
// String returns the human-readable contextualized error. This string is multi-line.
func (e *DecodeError) String() string {
return e.human
}
// Position returns the (line, column) pair indicating where the error
// occurred in the document. Positions are 1-indexed.
func (e *DecodeError) Position() (row int, column int) {
return e.line, e.column
}
// Key that was being processed when the error occurred. The key is present only
// if this DecodeError is part of a StrictMissingError.
func (e *DecodeError) Key() Key {
return e.key
}
// decodeErrorFromHighlight creates a DecodeError referencing a highlighted
// range of bytes from document.
//
// highlight needs to be a sub-slice of document, or this function panics.
//
// The function copies all bytes used in DecodeError, so that document and
// highlight can be freely deallocated.
//
//nolint:funlen
func wrapDecodeError(document []byte, de *unstable.ParserError) *DecodeError {
offset := danger.SubsliceOffset(document, de.Highlight)
errMessage := de.Error()
errLine, errColumn := positionAtEnd(document[:offset])
before, after := linesOfContext(document, de.Highlight, offset, 3)
var buf strings.Builder
maxLine := errLine + len(after) - 1
lineColumnWidth := len(strconv.Itoa(maxLine))
// Write the lines of context strictly before the error.
for i := len(before) - 1; i > 0; i-- {
line := errLine - i
buf.WriteString(formatLineNumber(line, lineColumnWidth))
buf.WriteString("|")
if len(before[i]) > 0 {
buf.WriteString(" ")
buf.Write(before[i])
}
buf.WriteRune('\n')
}
// Write the document line that contains the error.
buf.WriteString(formatLineNumber(errLine, lineColumnWidth))
buf.WriteString("| ")
if len(before) > 0 {
buf.Write(before[0])
}
buf.Write(de.Highlight)
if len(after) > 0 {
buf.Write(after[0])
}
buf.WriteRune('\n')
// Write the line with the error message itself (so it does not have a line
// number).
buf.WriteString(strings.Repeat(" ", lineColumnWidth))
buf.WriteString("| ")
if len(before) > 0 {
buf.WriteString(strings.Repeat(" ", len(before[0])))
}
buf.WriteString(strings.Repeat("~", len(de.Highlight)))
if len(errMessage) > 0 {
buf.WriteString(" ")
buf.WriteString(errMessage)
}
// Write the lines of context strictly after the error.
for i := 1; i < len(after); i++ {
buf.WriteRune('\n')
line := errLine + i
buf.WriteString(formatLineNumber(line, lineColumnWidth))
buf.WriteString("|")
if len(after[i]) > 0 {
buf.WriteString(" ")
buf.Write(after[i])
}
}
return &DecodeError{
message: errMessage,
line: errLine,
column: errColumn,
key: de.Key,
human: buf.String(),
}
}
func formatLineNumber(line int, width int) string {
format := "%" + strconv.Itoa(width) + "d"
return fmt.Sprintf(format, line)
}
func linesOfContext(document []byte, highlight []byte, offset int, linesAround int) ([][]byte, [][]byte) {
return beforeLines(document, offset, linesAround), afterLines(document, highlight, offset, linesAround)
}
func beforeLines(document []byte, offset int, linesAround int) [][]byte {
var beforeLines [][]byte
// Walk the document backward from the highlight to find previous lines
// of context.
rest := document[:offset]
backward:
for o := len(rest) - 1; o >= 0 && len(beforeLines) <= linesAround && len(rest) > 0; {
switch {
case rest[o] == '\n':
// handle individual lines
beforeLines = append(beforeLines, rest[o+1:])
rest = rest[:o]
o = len(rest) - 1
case o == 0:
// add the first line only if it's non-empty
beforeLines = append(beforeLines, rest)
break backward
default:
o--
}
}
return beforeLines
}
func afterLines(document []byte, highlight []byte, offset int, linesAround int) [][]byte {
var afterLines [][]byte
// Walk the document forward from the highlight to find the following
// lines of context.
rest := document[offset+len(highlight):]
forward:
for o := 0; o < len(rest) && len(afterLines) <= linesAround; {
switch {
case rest[o] == '\n':
// handle individual lines
afterLines = append(afterLines, rest[:o])
rest = rest[o+1:]
o = 0
case o == len(rest)-1:
// add last line only if it's non-empty
afterLines = append(afterLines, rest)
break forward
default:
o++
}
}
return afterLines
}
func positionAtEnd(b []byte) (row int, column int) {
row = 1
column = 1
for _, c := range b {
if c == '\n' {
row++
column = 1
} else {
column++
}
}
return
}