vfmt2: more convenient way to test multiple files for correct formatting

.gitattributes

@@ -1 +1,2 @@
-*.v linguist-language=V
+*.v linguist-language=V text=auto eol=lf
+*.vv linguist-language=V text=auto eol=lf

vlib/v/fmt/fmt.v

@@ -22,15 +22,14 @@ mut:
 	empty_line bool
 }
 
-pub fn fmt(file ast.File, table &table.Table) {
+pub fn fmt(file ast.File, table &table.Table) string {
 	mut f := Fmt{
 		out: strings.new_builder(1000)
 		table: table
 		indent: -1
 	}
 	f.stmts(file.stmts)
-	println('vfmt output:')
-	println(f.out.str())
+	return f.out.str()
 }
 
 pub fn (f mut Fmt) write(s string) {
@@ -98,7 +97,13 @@ fn (f mut Fmt) stmt(node ast.Stmt) {
 			f.writeln('')
 		}
 		ast.FnDecl {
-			f.writeln('fn ${it.name}() {')
+			return_type_sym := f.table.get_type_symbol(it.typ)
+			rtype_name := if return_type_sym.name == 'void' {
+				''
+			} else {
+				'${return_type_sym.name} '
+			}
+			f.writeln('fn ${it.name}() ${rtype_name}{')
 			f.stmts(it.stmts)
 			f.writeln('}\n')
 		}
@@ -208,7 +213,7 @@ fn (f mut Fmt) expr(node ast.Expr) {
 			f.stmts(it.stmts)
 			f.write('}')
 			if it.else_stmts.len > 0 {
-				f.writeln(' else { ')
+				f.writeln(' else {')
 				f.stmts(it.else_stmts)
 				f.write('}')
 			}

vlib/v/fmt/fmt_test.v

@@ -1,35 +1,83 @@
 import (
 	os
-	v.fmt
-	filepath
 	term
-	v.table
+	benchmark
+	filepath
+	v.fmt
 	v.parser
+	v.table
 )
 
 const (
-	nr_tests = 1
+	error_missing_vexe = 1
+	error_missing_diff = 2
+	error_failed_tests = 3
 )
 
 fn test_fmt() {
-	println('Running vfmt tests')
+	fmt_message := 'vfmt tests'
+	eprintln(term.header(fmt_message,'-'))
 	vexe := os.getenv('VEXE')
-	vroot := filepath.dir(vexe)
-	term_ok := term.ok_message('OK')
-	term_fail := term.fail_message('FAIL')
-	// for i in 1 .. nr_tests + 1 {
-	// path := '$vroot/vlib/v/fmt/tests/${i}.vv'
-	path := '$vroot/vlib/compiler/aparser.v'
-	println(path)
-	/*
-	mut ctext := os.read_file('$vroot/vlib/v/fmt/tests/${i}_out.vv') or {
-		panic(err)
+	if vexe.len == 0 || !os.exists(vexe) {
+		eprintln('VEXE must be set')
+		exit(error_missing_vexe)
+	}
+	vroot := filepath.dir(vexe)
+	tmpfolder := os.tmpdir()
+	diff_cmd := find_working_diff_command() or { '' }
+	mut fmt_bench := benchmark.new_benchmark()
+	// Lookup the existing test _input.vv files:
+	input_files := os.walk_ext('$vroot/vlib/v/fmt/tests', '_input.vv')
+	fmt_bench.set_total_expected_steps( input_files.len )
+	for istep, ipath in input_files {
+		fmt_bench.cstep = istep
+		fmt_bench.step()
+		ifilename := filepath.filename(ipath)
+		opath := ipath.replace('_input.vv', '_expected.vv')
+		if !os.exists(opath) {
+			fmt_bench.fail()
+			eprintln(fmt_bench.step_message_fail('missing file ${opath}'))
+			continue
+		}
+		expected_ocontent := os.read_file(opath) or {
+			fmt_bench.fail()			
+			eprintln(fmt_bench.step_message_fail('cannot read from ${opath}'))
+			continue
+		}
+		table := table.new_table()
+		file_ast := parser.parse_file(ipath, table)
+		result_ocontent := fmt.fmt(file_ast, table)
+		if expected_ocontent != result_ocontent {
+			fmt_bench.fail()
+			eprintln(fmt_bench.step_message_fail('file ${ipath} after formatting, does not look as expected.'))
+			if diff_cmd == '' {
+				eprintln('>> sorry, but no working "diff" CLI command can be found')
+				continue
+			}
+			vfmt_result_file := filepath.join(tmpfolder,'vfmt_run_over_${ifilename}')
+			os.write_file(vfmt_result_file, result_ocontent)
+			os.system('$diff_cmd --minimal  --text   --unified=2 --show-function-line="fn " "$opath" "$vfmt_result_file"')
+			continue
+		}
+		fmt_bench.ok()
+		eprintln(fmt_bench.step_message_ok('${ipath}'))
+	}
+	fmt_bench.stop()
+	eprintln(term.h_divider('-'))
+	eprintln(fmt_bench.total_message(fmt_message))
+	if fmt_bench.nfail > 0 {
+		exit(error_failed_tests)
 	}
-	ctext = ctext // unused warn
-	*/
-
-	table := table.new_table()
-	file := parser.parse_file(path, table)
-	fmt.fmt(file, table)
-	// }
+}
+
+fn find_working_diff_command() ?string {
+	for diffcmd in ['colordiff', 'diff', 'colordiff.exe', 'diff.exe'] {
+		p := os.exec('$diffcmd --version') or {
+			continue
+		}
+		if p.exit_code == 0 {
+			return diffcmd
+		}
+	}
+	return error('no working diff command found')
 }

vlib/v/fmt/tests/simple_expected.vv

@@ -0,0 +1,47 @@
+fn hello() {
+	mut a := 3 + 3
+	a = 10
+	a++
+	-23
+	b := 42
+	println('hello')
+	abc()
+	if true {
+		a = 10
+		a++
+	} else {
+		println('false')
+	}
+}
+
+const (
+	pi = 3.14
+)
+
+struct User {
+	name            string
+	age             int
+	very_long_field bool
+}
+
+fn abc() int {
+	mut u := User{
+		name: 'Bob'
+	}
+	u.age = 20
+	nums := [1, 2, 3]
+	number := nums[0]
+	return 0
+}
+
+fn new_user() User {
+	return User{
+		name: 'Serious Sam'
+		age: 19
+	}
+}
+
+fn voidfn() {
+	println('this is a function that does not return anything')
+}
+

vlib/v/fmt/tests/simple_input.vv

@@ -35,3 +35,16 @@ fn abc() int {
 	number := nums[0]
 	return 0
 }
+
+fn new_user()
+User
+{
+  return User{
+    name: 'Serious Sam'
+          age: 19
+           }
+}
+
+fn   voidfn(){
+ println('this is a function that does not return anything')
+   }

vlib/v/parser/parser.v

@@ -459,7 +459,7 @@ pub fn (p mut Parser) parse_ident(is_c bool) ast.Ident {
 fn (p mut Parser) struct_init() ast.StructInit {
 	typ := p.parse_type()
 	sym := p.table.get_type_symbol(typ)
-	p.warn('struct init typ=$sym.name')
+	//p.warn('struct init typ=$sym.name')
 	p.check(.lcbr)
 	mut field_names := []string
 	mut exprs := []ast.Expr