Refactor check functions.

Author: Denis Krivak

checks.go

@@ -43,26 +43,46 @@ func checkComments(comments []comment, settings Settings) []Issue {
 	var issues []Issue
 	for _, c := range comments {
 		if settings.Period {
-			if iss := checkCommentForPeriod(c); iss != nil {
+			if iss := checkPeriod(c); iss != nil {
 				issues = append(issues, *iss)
 			}
 		}
 		if settings.Capital {
-			if iss := checkCommentForCapital(c); len(iss) > 0 {
+			if iss := checkCapital(c); len(iss) > 0 {
 				issues = append(issues, iss...)
 			}
 		}
 	}
 	return issues
 }
 
-// checkCommentForPeriod checks that the last sentense of the comment ends
+// checkPeriod checks that the last sentense of the comment ends
 // in a period.
-func checkCommentForPeriod(c comment) *Issue {
-	pos, ok := checkPeriod(c.text)
-	if ok {
+func checkPeriod(c comment) *Issue {
+	// Check last non-empty line
+	var found bool
+	var line string
+	var pos position
+	lines := strings.Split(c.text, "\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 nil
 	}
+	// Correct line
+	if hasSuffix(line, lastChars) {
+		return nil
+	}
+
+	pos.column = len(line) + 1
 
 	// Shift position to its real value. `c.text` doesn't contain comment's
 	// special symbols: /* or //, and line indentations inside. It also
@@ -100,108 +120,30 @@ func checkCommentForPeriod(c comment) *Issue {
 	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
+// checkCapital checks that each sentense of the comment 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) {
+//
+//nolint:cyclop,funlen
+func checkCapital(c comment) []Issue {
 	// Remove common abbreviations from the comment
 	for _, abbr := range abbreviations {
 		repl := strings.ReplaceAll(abbr, ".", "_")
-		comment = strings.ReplaceAll(comment, abbr, repl)
+		c.text = strings.ReplaceAll(c.text, 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
 
+	var pp []position
 	pos := position{line: 1}
 	state := endOfSentence
-	if skipFirst {
+	if c.decl {
+		// Skip first
 		state = empty
 	}
-	for _, r := range comment {
+	for _, r := range c.text {
 		s := string(r)
 
 		pos.column++
@@ -229,12 +171,54 @@ func checkCapital(comment string, skipFirst bool) (pp []position) {
 		if state == endOfSentence && unicode.IsLower(r) {
 			pp = append(pp, position{
 				line:   pos.line,
-				column: runeToByteColumn(comment, pos.column),
+				column: runeToByteColumn(c.text, pos.column),
 			})
 		}
 		state = empty
 	}
-	return pp
+	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
 }
 
 // isSpecialBlock checks that given block of comment lines is special and