v vet: give an error for trailing whitespace (#9574)

cmd/tools/vtest-cleancode.v

@@ -5,7 +5,9 @@ import testing
 import v.util
 
 const (
-	vet_known_failing_exceptions    = []string{}
+	vet_known_failing_exceptions    = [
+		'vlib/v/gen/js/js.v' /* trailing space */,
+	]
 	vet_folders                     = [
 		'vlib/sqlite',
 		'vlib/v',
@@ -115,7 +117,8 @@ fn tsession(vargs string, tool_source string, tool_cmd string, tool_args string,
 }
 
 fn v_test_vetting(vargs string) {
-	vet_session := tsession(vargs, 'vvet', 'v vet', 'vet', vet_folders, vet_known_failing_exceptions)
+	expanded_vet_list := util.find_all_v_files(vet_folders) or { return }
+	vet_session := tsession(vargs, 'vvet', 'v vet', 'vet', expanded_vet_list, vet_known_failing_exceptions)
 	fmt_cmd, fmt_args := if is_fix { 'v fmt -w', 'fmt -w' } else { 'v fmt -verify', 'fmt -verify' }
 	expanded_vfmt_list := util.find_all_v_files(vfmt_verify_list) or { return }
 	verify_session := tsession(vargs, 'vfmt.v', fmt_cmd, fmt_args, expanded_vfmt_list,

cmd/tools/vvet/tests/trailing_space.out

@@ -0,0 +1,7 @@
+cmd/tools/vvet/tests/trailing_space.vv:5: error: Looks like you have trailing whitespace.
+cmd/tools/vvet/tests/trailing_space.vv:6: error: Looks like you have trailing whitespace.
+cmd/tools/vvet/tests/trailing_space.vv:7: error: Looks like you have trailing whitespace.
+cmd/tools/vvet/tests/trailing_space.vv:8: error: Looks like you have trailing whitespace.
+cmd/tools/vvet/tests/trailing_space.vv:9: error: Looks like you have trailing whitespace.
+cmd/tools/vvet/tests/trailing_space.vv:13: error: Looks like you have trailing whitespace.
+cmd/tools/vvet/tests/trailing_space.vv:15: error: Looks like you have trailing whitespace.

cmd/tools/vvet/tests/trailing_space.vv

@@ -0,0 +1,16 @@
+// NB: This file has and *should* have trailing spaces.
+// When making changes, please ensure they are not removed.
+
+fn after_comments() {
+	// spaces after line comments give errors  
+	/*  
+	in block comments  
+	too  
+	*/  
+}
+
+fn main() {
+	var := 'error about the spaces right there'  
+	no_err := "inside multi line strings it's fine.  
+but not after"  
+}

cmd/tools/vvet/vvet.v

@@ -229,6 +229,7 @@ fn (mut vt Vet) error(msg string, line int, fix vet.FixKind) {
 		pos: pos
 		kind: .error
 		fix: fix
+		typ: .default
 	}
 }
 
@@ -242,6 +243,7 @@ fn (mut vt Vet) warn(msg string, line int, fix vet.FixKind) {
 		pos: pos
 		kind: .warning
 		fix: fix
+		typ: .default
 	}
 	if vt.opt.is_werror {
 		w.kind = .error

vlib/v/parser/parser.v

@@ -207,12 +207,16 @@ pub fn parse_vet_file(path string, table_ &ast.Table, pref &pref.Preferences) (a
 		global_scope: global_scope
 	}
 	p.set_path(path)
-	if p.scanner.text.contains('\n  ') {
+	if p.scanner.text.contains_any_substr(['\n  ', ' \n']) {
 		source_lines := os.read_lines(path) or { []string{} }
 		for lnumber, line in source_lines {
 			if line.starts_with('  ') {
 				p.vet_error('Looks like you are using spaces for indentation.', lnumber,
-					.vfmt)
+					.vfmt, .space_indent)
+			}
+			if line.ends_with(' ') {
+				p.vet_error('Looks like you have trailing whitespace.', lnumber, .unknown,
+					.trailing_space)
 			}
 		}
 	}
@@ -617,10 +621,10 @@ pub fn (mut p Parser) comment() ast.Comment {
 	pos.last_line = pos.line_nr + text.count('\n')
 	p.next()
 	is_multi := text.contains('\n')
-	// Filter out space indentation vet errors inside block comments
+	// Filter out false positive space indent vet errors inside comments
 	if p.vet_errors.len > 0 && is_multi {
-		p.vet_errors = p.vet_errors.filter(!(it.pos.line_nr - 1 > pos.line_nr
-			&& it.pos.line_nr - 1 <= pos.last_line))
+		p.vet_errors = p.vet_errors.filter(it.typ != .space_indent
+			|| it.pos.line_nr - 1 > pos.last_line || it.pos.line_nr - 1 <= pos.line_nr)
 	}
 	return ast.Comment{
 		is_multi: is_multi
@@ -1648,7 +1652,7 @@ pub fn (mut p Parser) note_with_pos(s string, pos token.Position) {
 	}
 }
 
-pub fn (mut p Parser) vet_error(msg string, line int, fix vet.FixKind) {
+pub fn (mut p Parser) vet_error(msg string, line int, fix vet.FixKind, typ vet.ErrorType) {
 	pos := token.Position{
 		line_nr: line + 1
 	}
@@ -1658,6 +1662,7 @@ pub fn (mut p Parser) vet_error(msg string, line int, fix vet.FixKind) {
 		pos: pos
 		kind: .error
 		fix: fix
+		typ: typ
 	}
 }
 
@@ -2339,9 +2344,13 @@ fn (mut p Parser) string_expr() ast.Expr {
 	pos.last_line = pos.line_nr + val.count('\n')
 	if p.peek_tok.kind != .str_dollar {
 		p.next()
-		if p.vet_errors.len > 0 && val.contains('\n  ') {
-			p.vet_errors = p.vet_errors.filter(!(it.pos.line_nr > pos.line_nr - 1
-				&& it.pos.line_nr <= pos.last_line - 1))
+		// Filter out false positive vet errors inside strings
+		if p.vet_errors.len > 0 {
+			p.vet_errors = p.vet_errors.filter(
+				(it.typ == .trailing_space && it.pos.line_nr - 1 >= pos.last_line)
+				|| (it.typ != .trailing_space && it.pos.line_nr - 1 > pos.last_line)
+				|| (it.typ == .space_indent && it.pos.line_nr - 1 <= pos.line_nr)
+				|| (it.typ != .space_indent && it.pos.line_nr - 1 < pos.line_nr))
 		}
 		node = ast.StringLiteral{
 			val: val

vlib/v/parser/pratt.v

@@ -447,7 +447,8 @@ fn (mut p Parser) infix_expr(left ast.Expr) ast.Expr {
 	p.expecting_type = prev_expecting_type
 	if p.pref.is_vet && op in [.key_in, .not_in] && right is ast.ArrayInit
 		&& (right as ast.ArrayInit).exprs.len == 1 {
-		p.vet_error('Use `var == value` instead of `var in [value]`', pos.line_nr, vet.FixKind.vfmt)
+		p.vet_error('Use `var == value` instead of `var in [value]`', pos.line_nr, vet.FixKind.vfmt,
+			.default)
 	}
 	mut or_stmts := []ast.Stmt{}
 	mut or_kind := ast.OrKind.absent

vlib/v/scanner/scanner.v

@@ -1376,6 +1376,7 @@ fn (mut s Scanner) vet_error(msg string, fix vet.FixKind) {
 		}
 		kind: .error
 		fix: fix
+		typ: .default
 	}
 	s.vet_errors << ve
 }

vlib/v/vet/vet.v

@@ -15,6 +15,13 @@ pub enum FixKind {
 	vfmt
 }
 
+// ErrorType is used to filter out false positive errors under specific conditions
+pub enum ErrorType {
+	default
+	space_indent
+	trailing_space
+}
+
 pub struct Error {
 pub mut:
 	kind ErrorKind [required]
@@ -25,4 +32,5 @@ pub:
 	file_path string // file where the error have origin
 	pos       token.Position // position in the file
 	fix       FixKind        [required]
+	typ       ErrorType      [required]
 }