fmt: fix interface fields/methods alignment

cmd/tools/modules/testing/output.v

@@ -30,13 +30,13 @@ pub:
 
 pub interface Reporter {
 mut:
-	session_start(message string, mut ts TestSession) // called once per test session, in the main thread, suitable for setting up supporting infrastructure.
-	session_stop(message string, mut ts TestSession) // called once per test session, in the main thread, after everything else, suitable for summaries, creating .xml reports, uploads etc.
+	session_start(message string, mut ts TestSession)        // called once per test session, in the main thread, suitable for setting up supporting infrastructure.
+	session_stop(message string, mut ts TestSession)         // called once per test session, in the main thread, after everything else, suitable for summaries, creating .xml reports, uploads etc.
 	worker_threads_start(files []string, mut ts TestSession) // called once per test session, in the main thread, right before all the worker threads start
-	worker_threads_finish(mut ts TestSession) // called once per test session, in the main thread, right after all the worker threads finish
+	worker_threads_finish(mut ts TestSession)                // called once per test session, in the main thread, right after all the worker threads finish
 	//
 	report(index int, log_msg LogMessage) // called once per each message, that will be shown (ok/fail/skip etc), only in the reporting thread.
-	report_stop() // called just once after all messages are processed, only in the reporting thread, but before stop_session.
+	report_stop()                         // called just once after all messages are processed, only in the reporting thread, but before stop_session.
 	//
 	// TODO: reconsider, whether the next methods, should be kept for all reporters, or just moved inside the normal reporter, to simplify the interface
 	progress(index int, message string)

vlib/v/fmt/fmt.v

@@ -1400,41 +1400,50 @@ pub fn (mut f Fmt) interface_decl(node ast.InterfaceDecl) {
 	}
 
 	mut type_align := new_field_align()
-	mut comment_align := new_field_align()
-	mut default_expr_align := new_field_align()
-	mut attr_align := new_field_align()
+	mut comment_align := new_field_align(use_threshold: true)
+	mut default_expr_align := new_field_align(use_threshold: true)
+	mut attr_align := new_field_align(use_threshold: true)
 	mut field_types := []string{cap: node.fields.len}
 
 	// Calculate the alignments first
 	f.calculate_alignment(node.fields, mut type_align, mut comment_align, mut default_expr_align, mut
 		attr_align, mut field_types)
 
+	mut method_comment_align := new_field_align(use_threshold: true)
+	for method in node.methods {
+		end_comments := method.comments.filter(it.pos.pos > method.pos.pos)
+		if end_comments.len > 0 {
+			method_str := f.table.stringify_fn_decl(&method, f.cur_mod, f.mod2alias, false).all_after_first('fn ')
+			method_comment_align.add_info(method_str.len, method.pos.line_nr)
+		}
+	}
+
 	// TODO: alignment, comments, etc.
 	for field in immut_fields {
 		if field.has_prev_newline {
 			f.writeln('')
 		}
-		f.interface_field(field, type_align.max_len(field.pos.line_nr))
+		f.interface_field(field, mut type_align, mut comment_align)
 	}
 	for method in immut_methods {
 		if method.has_prev_newline {
 			f.writeln('')
 		}
-		f.interface_method(method)
+		f.interface_method(method, mut method_comment_align)
 	}
 	if mut_fields.len + mut_methods.len > 0 {
 		f.writeln('mut:')
 		for field in mut_fields {
 			if field.has_prev_newline {
 				f.writeln('')
 			}
-			f.interface_field(field, type_align.max_len(field.pos.line_nr))
+			f.interface_field(field, mut type_align, mut comment_align)
 		}
 		for method in mut_methods {
 			if method.has_prev_newline {
 				f.writeln('')
 			}
-			f.interface_method(method)
+			f.interface_method(method, mut method_comment_align)
 		}
 	}
 	f.writeln('}\n')
@@ -1497,7 +1506,7 @@ pub fn (mut f Fmt) calculate_alignment(fields []ast.StructField, mut type_align
 	}
 }
 
-pub fn (mut f Fmt) interface_field(field ast.StructField, max_len int) {
+pub fn (mut f Fmt) interface_field(field ast.StructField, mut type_align FieldAlign, mut comment_align FieldAlign) {
 	ft := f.no_cur_mod(f.table.type_to_str_using_aliases(field.typ, f.mod2alias))
 	mut pre_cmts, mut end_cmts, mut next_line_cmts := []ast.Comment{}, []ast.Comment{}, []ast.Comment{}
 	for cmt in field.comments {
@@ -1511,7 +1520,6 @@ pub fn (mut f Fmt) interface_field(field ast.StructField, max_len int) {
 	if pre_cmts.len > 0 {
 		f.comments(pre_cmts, level: .indent)
 	}
-	comments_len := f.line_len - before_len
 
 	sym := f.table.sym(field.typ)
 	if sym.info is ast.Struct {
@@ -1525,10 +1533,12 @@ pub fn (mut f Fmt) interface_field(field ast.StructField, max_len int) {
 		f.write('\t${field.name} ')
 	}
 	if !(sym.info is ast.Struct && sym.info.is_anon) {
-		f.write(strings.repeat(` `, max_len - field.name.len - comments_len))
+		f.write(strings.repeat(` `, type_align.max_len(field.pos.line_nr) - field.name.len))
 		f.write(ft)
 	}
 	if end_cmts.len > 0 {
+		f.write(strings.repeat(` `, comment_align.max_len(field.pos.line_nr) - ft.len))
+		f.write(' ')
 		f.comments(end_cmts, level: .indent)
 	} else {
 		f.writeln('')
@@ -1539,16 +1549,22 @@ pub fn (mut f Fmt) interface_field(field ast.StructField, max_len int) {
 	f.mark_types_import_as_used(field.typ)
 }
 
-pub fn (mut f Fmt) interface_method(method ast.FnDecl) {
+pub fn (mut f Fmt) interface_method(method ast.FnDecl, mut comment_align FieldAlign) {
 	before_comments := method.comments.filter(it.pos.pos < method.pos.pos)
 	end_comments := method.comments.filter(it.pos.pos > method.pos.pos)
 	if before_comments.len > 0 {
 		f.comments(before_comments, level: .indent)
 	}
 	f.write('\t')
-	f.write(f.table.stringify_fn_decl(&method, f.cur_mod, f.mod2alias, false).all_after_first('fn '))
-	f.comments(end_comments, same_line: true, has_nl: false, level: .indent)
-	f.writeln('')
+	method_str := f.table.stringify_fn_decl(&method, f.cur_mod, f.mod2alias, false).all_after_first('fn ')
+	f.write(method_str)
+	if end_comments.len > 0 {
+		f.write(strings.repeat(` `, comment_align.max_len(method.pos.line_nr) - method_str.len))
+		f.write(' ')
+		f.comments(end_comments, level: .indent)
+	} else {
+		f.writeln('')
+	}
 	f.comments(method.next_comments, level: .indent)
 	for param in method.params {
 		f.mark_types_import_as_used(param.typ)

vlib/v/fmt/tests/interface_declaration_comments_keep.vv

@@ -1,6 +1,6 @@
 pub interface ReaderWriter {
 	read(mut buf []u8) ?int // from Reader
-	write(buf []u8) ?int // from Writer
+	write(buf []u8) ?int    // from Writer
 }
 
 interface Speaker {
@@ -38,10 +38,10 @@ mut:
 	assert_fails  u64
 	test_fn_info  &TestFnMetaInfo // filled in by generated code, before .fn_start() is called.
 	start(ntests int) // called before all tests, you can initialise private data here. ntests is the number of test functions in the _test.v file.
-	finish() // called after all tests are finished, you should free all the private data here.
+	finish()          // called after all tests are finished, you should free all the private data here.
 	//
 	fn_start() // called at the start of each test_ function
-	fn_pass() // called at the end of each test_ function, with no failed assertion
+	fn_pass()  // called at the end of each test_ function, with no failed assertion
 	fn_error(line_nr int, file string, mod string, fn_name string, errmsg string) // called only for `fn test_xyz() ? { return error('message') }`
 	fn_fail() // called at the end of each test_ function, with a failed assertion, *or* returning an error
 	//

vlib/v/preludes/test_runner.c.v

@@ -13,29 +13,28 @@ __global test_runner TestRunner
 interface TestRunner {
 mut:
 	file_test_info      VTestFileMetaInfo // filled in by generated code, before .start() is called.
-	fn_test_info        VTestFnMetaInfo // filled in by generated code, before .fn_start() is called.
-	fn_assert_passes    u64 // reset this to 0 in .fn_start(), increase it in .assert_pass()
-	fn_passes           u64 // increase this in .fn_pass()
-	fn_fails            u64 // increase this in .fn_fails()
-	total_assert_passes u64 // increase this in .assert_pass()
-	total_assert_fails  u64 // increase this in .assert_fail()
+	fn_test_info        VTestFnMetaInfo   // filled in by generated code, before .fn_start() is called.
+	fn_assert_passes    u64               // reset this to 0 in .fn_start(), increase it in .assert_pass()
+	fn_passes           u64               // increase this in .fn_pass()
+	fn_fails            u64               // increase this in .fn_fails()
+	total_assert_passes u64               // increase this in .assert_pass()
+	total_assert_fails  u64               // increase this in .assert_fail()
+
 	start(ntests int) // called before all tests, you can initialise private data here. ntests is the number of test functions in the _test.v file.
-	finish() // called after all tests are finished, you can print some stats if you want here.
-	exit_code() int // called right after finish(), it should return the exit code, that the test program will exit with.
-	//
+	finish()          // called after all tests are finished, you can print some stats if you want here.
+	exit_code() int   // called right after finish(), it should return the exit code, that the test program will exit with.
+
 	fn_start() bool // called before the start of each test_ function. Return false, if the function should be skipped.
-	fn_pass() // called after the end of each test_ function, with NO failed assertion.
-	fn_fail() // called after the end of each test_ function, with a failed assertion, *or* returning an error.
+	fn_pass()       // called after the end of each test_ function, with NO failed assertion.
+	fn_fail()       // called after the end of each test_ function, with a failed assertion, *or* returning an error.
 	fn_error(line_nr int, file string, mod string, fn_name string, errmsg string) // called only for `fn test_xyz() ? { return error('message') }`, before .fn_fail() is called.
-	//
+
 	assert_pass(i &VAssertMetaInfo) // called after each `assert true`.
 	assert_fail(i &VAssertMetaInfo) // called after each `assert false`.
-	//
+
 	free() // you should free all the private data of your runner here.
 }
 
-//
-
 struct VTestFileMetaInfo {
 	file  string
 	tests int
@@ -57,8 +56,6 @@ fn (i &VTestFileMetaInfo) free() {
 	}
 }
 
-//
-
 struct VTestFnMetaInfo {
 	name    string
 	mod     string
@@ -85,8 +82,6 @@ fn (i &VTestFnMetaInfo) free() {
 	}
 }
 
-//
-
 @[typedef]
 pub struct C.main__TestRunner {
 mut: