wg-quicker/vendor/github.com/tetafro/godot/checks.go

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2022-01-07 20:20:48 +01:00
package godot
import (
"go/token"
"regexp"
"strings"
"unicode"
)
// Error messages.
const (
noPeriodMessage = "Comment should end in a period"
noCapitalMessage = "Sentence should start with a capital letter"
)
var (
// List of valid sentence ending.
// A sentence can be inside parenthesis, and therefore ends with parenthesis.
lastChars = []string{".", "?", "!", ".)", "?)", "!)", "。", "", "", "。)", "", "", specialReplacer}
// Abbreviations to exclude from capital letters check.
abbreviations = []string{"i.e.", "i. e.", "e.g.", "e. g.", "etc."}
// Special tags in comments like "// nolint:", or "// +k8s:".
tags = regexp.MustCompile(`^\+?[a-z0-9]+:`)
// Special hashtags in comments like "// #nosec".
hashtags = regexp.MustCompile(`^#[a-z]+($|\s)`)
// URL at the end of the line.
endURL = regexp.MustCompile(`[a-z]+://[^\s]+$`)
)
// checkComments checks every comment accordings to the rules from
// `settings` argument.
func checkComments(comments []comment, settings Settings) []Issue {
var issues []Issue // nolint: prealloc
for _, c := range comments {
if settings.Period {
if iss := checkCommentForPeriod(c); iss != nil {
issues = append(issues, *iss)
}
}
if settings.Capital {
if iss := checkCommentForCapital(c); len(iss) > 0 {
issues = append(issues, iss...)
}
}
}
return issues
}
// checkCommentForPeriod checks that the last sentense of the comment ends
// in a period.
func checkCommentForPeriod(c comment) *Issue {
pos, ok := checkPeriod(c.text)
if ok {
return nil
}
// Shift position to its real value. `c.text` doesn't contain comment's
// special symbols: /* or //, and line indentations inside. It also
// contains */ in the end in case of block comment.
pos.column += strings.Index(
c.lines[pos.line-1],
strings.Split(c.text, "\n")[pos.line-1],
)
iss := Issue{
Pos: token.Position{
Filename: c.start.Filename,
Offset: c.start.Offset,
Line: pos.line + c.start.Line - 1,
Column: pos.column,
},
Message: noPeriodMessage,
}
// Make a replacement. Use `pos.line` to get an original line from
// attached lines. Use `iss.Pos.Column` because it's a position in
// the original line.
original := c.lines[pos.line-1]
if len(original) < iss.Pos.Column-1 {
// This should never happen. Avoid panics, skip this check.
return nil
}
iss.Replacement = original[:iss.Pos.Column-1] + "." +
original[iss.Pos.Column-1:]
// Save replacement to raw lines to be able to combine it with
// further replacements
c.lines[pos.line-1] = iss.Replacement
return &iss
}
// checkCommentForCapital checks that each sentense of the comment starts with
// a capital letter.
// nolint: unparam
func checkCommentForCapital(c comment) []Issue {
pp := checkCapital(c.text, c.decl)
if len(pp) == 0 {
return nil
}
issues := make([]Issue, len(pp))
for i, pos := range pp {
// Shift position by the length of comment's special symbols: /* or //
isBlock := strings.HasPrefix(c.lines[0], "/*")
if (isBlock && pos.line == 1) || !isBlock {
pos.column += 2
}
iss := Issue{
Pos: token.Position{
Filename: c.start.Filename,
Offset: c.start.Offset,
Line: pos.line + c.start.Line - 1,
Column: pos.column + c.start.Column - 1,
},
Message: noCapitalMessage,
}
// Make a replacement. Use `pos.original` to get an original original from
// attached lines. Use `iss.Pos.Column` because it's a position in
// the original original.
original := c.lines[pos.line-1]
col := byteToRuneColumn(original, iss.Pos.Column) - 1
rep := string(unicode.ToTitle([]rune(original)[col])) // capital letter
if len(original) < iss.Pos.Column-1+len(rep) {
// This should never happen. Avoid panics, skip this check.
continue
}
iss.Replacement = original[:iss.Pos.Column-1] + rep +
original[iss.Pos.Column-1+len(rep):]
// Save replacement to raw lines to be able to combine it with
// further replacements
c.lines[pos.line-1] = iss.Replacement
issues[i] = iss
}
return issues
}
// checkPeriod checks that the last sentense of the text ends in a period.
// NOTE: Returned position is a position inside given text, not in the
// original file.
func checkPeriod(comment string) (pos position, ok bool) {
// Check last non-empty line
var found bool
var line string
lines := strings.Split(comment, "\n")
for i := len(lines) - 1; i >= 0; i-- {
line = strings.TrimRightFunc(lines[i], unicode.IsSpace)
if line == "" {
continue
}
found = true
pos.line = i + 1
break
}
// All lines are empty
if !found {
return position{}, true
}
// Correct line
if hasSuffix(line, lastChars) {
return position{}, true
}
pos.column = len(line) + 1
return pos, false
}
// checkCapital checks that each sentense of the text starts with
// a capital letter.
// NOTE: First letter is not checked in declaration comments, because they
// can describe unexported functions, which start with small letter.
func checkCapital(comment string, skipFirst bool) (pp []position) {
// Remove common abbreviations from the comment
for _, abbr := range abbreviations {
repl := strings.ReplaceAll(abbr, ".", "_")
comment = strings.ReplaceAll(comment, abbr, repl)
}
// List of states during the scan: `empty` - nothing special,
// `endChar` - found one of sentence ending chars (.!?),
// `endOfSentence` - found `endChar`, and then space or newline.
const empty, endChar, endOfSentence = 1, 2, 3
pos := position{line: 1}
state := endOfSentence
if skipFirst {
state = empty
}
for _, r := range comment {
s := string(r)
pos.column++
if s == "\n" {
pos.line++
pos.column = 0
if state == endChar {
state = endOfSentence
}
continue
}
if s == "." || s == "!" || s == "?" {
state = endChar
continue
}
if s == ")" && state == endChar {
continue
}
if s == " " {
if state == endChar {
state = endOfSentence
}
continue
}
if state == endOfSentence && unicode.IsLower(r) {
pp = append(pp, position{
line: pos.line,
column: runeToByteColumn(comment, pos.column),
})
}
state = empty
}
return pp
}
// isSpecialBlock checks that given block of comment lines is special and
// shouldn't be checked as a regular sentence.
func isSpecialBlock(comment string) bool {
// Skip cgo code blocks
// TODO: Find a better way to detect cgo code
if strings.HasPrefix(comment, "/*") && (strings.Contains(comment, "#include") ||
strings.Contains(comment, "#define")) {
return true
}
return false
}
// isSpecialBlock checks that given comment line is special and
// shouldn't be checked as a regular sentence.
func isSpecialLine(comment string) bool {
// Skip cgo export tags: https://golang.org/cmd/cgo/#hdr-C_references_to_Go
if strings.HasPrefix(comment, "//export ") {
return true
}
comment = strings.TrimPrefix(comment, "//")
comment = strings.TrimPrefix(comment, "/*")
// Don't check comments starting with space indentation - they may
// contain code examples, which shouldn't end with period
if strings.HasPrefix(comment, " ") ||
strings.HasPrefix(comment, " \t") ||
strings.HasPrefix(comment, "\t") {
return true
}
// Skip tags and URLs
comment = strings.TrimSpace(comment)
if tags.MatchString(comment) ||
hashtags.MatchString(comment) ||
endURL.MatchString(comment) ||
strings.HasPrefix(comment, "+build") {
return true
}
return false
}
func hasSuffix(s string, suffixes []string) bool {
for _, suffix := range suffixes {
if strings.HasSuffix(s, suffix) {
return true
}
}
return false
}
// The following two functions convert byte and rune indexes.
//
// Example:
// text: a b c Ш e f
// runes: 1 2 3 4 5 6
// bytes: 0 1 2 3 5 6
// The reason of the difference is that the size of "Ш" is 2 bytes.
// NOTE: Works only for 1-based indexes (line columns).
// byteToRuneColumn converts byte index inside the string to rune index.
func byteToRuneColumn(s string, i int) int {
return len([]rune(s[:i-1])) + 1
}
// runeToByteColumn converts rune index inside the string to byte index.
func runeToByteColumn(s string, i int) int {
return len(string([]rune(s)[:i-1])) + 1
}