feature: Improve error-strings rule to detect acronyms and proper nouns (#1287)

Author: chavacava

rule/error_strings.go

@@ -178,21 +178,29 @@ func (lintErrorStrings) checkArg(expr *ast.CallExpr, arg int) (s *ast.BasicLit,
 func lintErrorString(s string) (isClean bool, conf float64) {
 const basicConfidence = 0.8
 const capConfidence = basicConfidence - 0.2
-first, firstN := utf8.DecodeRuneInString(s)
+
 last, _ := utf8.DecodeLastRuneInString(s)
 if last == '.' || last == ':' || last == '!' || last == '\n' {
 return false, basicConfidence
 }
-if unicode.IsUpper(first) {
-// People use proper nouns and exported Go identifiers in error strings,
-// so decrease the confidence of warnings for capitalization.
-if len(s) <= firstN {
-return false, capConfidence
+
+first, firstN := utf8.DecodeRuneInString(s)
+if !unicode.IsUpper(first) {
+return true, 0
+}
+
+// People use proper nouns and exported Go identifiers in error strings,
+// so decrease the confidence of warnings for capitalization.
+for _, r := range s[firstN:] {
+if unicode.IsSpace(r) {
+break
 }
-// Flag strings starting with something that doesn't look like an initialism.
-if second, _ := utf8.DecodeRuneInString(s[firstN:]); !unicode.IsUpper(second) {
-return false, capConfidence
+
+if unicode.IsUpper(r) || unicode.IsDigit(r) {
+return true, 0 // accept words with more than 2 capital letters or digits (e.g. GitHub, URLs, I2000)
 }
 }
-return true, 0
+
+// Flag strings starting with something that doesn't look like an initialism.
+return false, capConfidence
 }

testdata/golint/error_strings.go

@@ -16,6 +16,13 @@ func g(x int) error {
 err = fmt.Errorf("Newlines are really fun\n") // MATCH /error strings should not be capitalized or end with punctuation or a newline/
 err = errors.New(`too much stuff.`) // MATCH /error strings should not be capitalized or end with punctuation or a newline/
 err = errors.New("This %d is too low", x) // MATCH /error strings should not be capitalized or end with punctuation or a newline/
+err = errors.New("GitHub should be ok", x)
+err = errors.New("OTP should be ok", x)
+err = errors.New("A JSON should be not ok", x) // MATCH /error strings should not be capitalized or end with punctuation or a newline/
+err = errors.New("H264 should be ok", x)
+err = errors.New("I/O should be ok", x)
+err = errors.New("U.S. should be ok", x)
+err = errors.New("Wi-Fi should be ok", x)
 
 // Non-regression test for issue #610
 d.stack.Push(from)