fmt: reset const field align after multi line exprs (#9916)

cmd/tools/vtest-cleancode.v

@@ -37,9 +37,9 @@ const (
 		'vlib/v/tests/generics_test.v', /* multi_generic_args<Foo<int>, Foo<int> >(...) becomes .... Foo<int>>(...) which does not parse */
 		'vlib/v/tests/string_interpolation_test.v' /* TODO byteptr: &byte.str() behaves differently than byteptr.str() */,
 		'vlib/v/gen/js/tests/js.v', /* local `hello` fn, gets replaced with module `hello` aliased as `hl` */
-		'vlib/v/gen/c/cheaders.v' /* the preprocessor directives are formated to the V standard, even though they are in a string literal */,
 		'examples/c_interop_wkhtmltopdf.v', /* &charptr --> &&char */
 		'examples/path_tracing.v', /* block --> line comments corrupts code */
+		'vlib/v/gen/c/cheaders.v' /* infix wrapping error */,
 	]
 	vfmt_verify_list                = [
 		'cmd/',

vlib/v/fmt/fmt.v

@@ -657,6 +657,9 @@ fn expr_is_single_line(expr ast.Expr) bool {
 				}
 			}
 		}
+		ast.StringLiteral {
+			return expr.pos.line_nr == expr.pos.last_line
+		}
 		else {}
 	}
 	return true
@@ -888,6 +891,12 @@ pub fn (mut f Fmt) comp_for(node ast.CompFor) {
 	f.writeln('}')
 }
 
+struct ConstAlignInfo {
+mut:
+	max      int
+	last_idx int
+}
+
 pub fn (mut f Fmt) const_decl(node ast.ConstDecl) {
 	if node.is_pub {
 		f.write('pub ')
@@ -901,22 +910,36 @@ pub fn (mut f Fmt) const_decl(node ast.ConstDecl) {
 		f.inside_const = false
 	}
 	f.write('const ')
-	mut max := 0
+	mut align_infos := []ConstAlignInfo{}
 	if node.is_block {
 		f.writeln('(')
-		for field in node.fields {
-			if field.name.len > max {
-				max = field.name.len
+		mut info := ConstAlignInfo{}
+		for i, field in node.fields {
+			if field.name.len > info.max {
+				info.max = field.name.len
+			}
+			if !expr_is_single_line(field.expr) {
+				info.last_idx = i
+				align_infos << info
+				info = ConstAlignInfo{}
 			}
 		}
+		info.last_idx = node.fields.len
+		align_infos << info
 		f.indent++
+	} else {
+		align_infos << ConstAlignInfo{0, 1}
 	}
 	mut prev_field := if node.fields.len > 0 {
 		ast.Node(node.fields[0])
 	} else {
 		ast.Node(ast.NodeError{})
 	}
-	for field in node.fields {
+	mut align_idx := 0
+	for i, field in node.fields {
+		if i > align_infos[align_idx].last_idx {
+			align_idx++
+		}
 		if field.comments.len > 0 {
 			if f.should_insert_newline_before_node(ast.Expr(field.comments[0]), prev_field) {
 				f.writeln('')
@@ -929,7 +952,7 @@ pub fn (mut f Fmt) const_decl(node ast.ConstDecl) {
 		}
 		name := field.name.after('.')
 		f.write('$name ')
-		f.write(strings.repeat(` `, max - field.name.len))
+		f.write(strings.repeat(` `, align_infos[align_idx].max - field.name.len))
 		f.write('= ')
 		f.expr(field.expr)
 		f.writeln('')

vlib/v/fmt/tests/consts_keep.vv

@@ -1 +1,27 @@
 const font = $embed_file('../assets/fonts/RobotoMono-Regular.ttf')
+
+const (
+	test_alignment = 123
+	foo            = Foo{
+		f: 'foo'
+	}
+	spam     = 456
+	egg      = 'lorem ipsum'
+	spameggs = true
+)
+
+const (
+	bar = 'A string
+spanning multiple
+lines'
+	baz            = 'short'
+	some_long_name = MyStruct{
+		x: 42
+	}
+)
+
+const (
+	a   = 123
+	abc = 123
+	b   = 123
+)

vlib/v/gen/c/cheaders.v

@@ -498,8 +498,8 @@ static inline void make_secret(uint64_t seed, uint64_t *secret){
 #define _PUSH_MANY(arr, val, tmp, tmp_typ) {tmp_typ tmp = (val); array_push_many(arr, tmp.data, tmp.len);}
 #define _IN_MAP(val, m) map_exists(m, val)
 '
-	c_headers                       =
-		c_helper_macros + c_unsigned_comparison_functions + c_common_macros + r'
+	c_headers       = c_helper_macros + c_unsigned_comparison_functions + c_common_macros +
+		r'
 // c_headers
 typedef int (*qsort_callback_func)(const void*, const void*);
 #include <stdio.h>  // TODO remove all these includes, define all function signatures and types manually
@@ -728,8 +728,7 @@ typedef bool (*MapEqFn)(voidptr, voidptr);
 typedef void (*MapCloneFn)(voidptr, voidptr);
 typedef void (*MapFreeFn)(voidptr);
 '
-	bare_c_headers                  = c_helper_macros + c_unsigned_comparison_functions +
-		c_common_macros +
+	bare_c_headers = c_helper_macros + c_unsigned_comparison_functions + c_common_macros +
 		'
 
 #define _VFREESTANDING