fmt: put the opening brace on a new line again for infix (#8336)

vlib/v/checker/checker.v

@@ -1537,7 +1537,8 @@ pub fn (mut c Checker) call_method(mut call_expr ast.CallExpr) table.Type {
 		}
 		if call_expr.generic_types.len > 0 && method.return_type != 0 {
 			if typ := c.resolve_generic_type(method.return_type, method.generic_names,
-				call_expr.generic_types) {
+				call_expr.generic_types)
+			{
 				call_expr.return_type = typ
 				return typ
 			}

vlib/v/fmt/fmt.v

@@ -1564,8 +1564,17 @@ pub fn (mut f Fmt) if_expr(it ast.IfExpr) {
 			}
 			if i < it.branches.len - 1 || !it.has_else {
 				f.write('${dollar}if ')
+				cur_pos := f.out.len
 				f.expr(branch.cond)
-				f.write(' ')
+				cond_len := f.out.len - cur_pos
+				is_cond_wrapped := cond_len > 0
+					&& (branch.cond is ast.IfGuardExpr || branch.cond is ast.CallExpr)
+					&& '\n' in f.out.last_n(cond_len)
+				if is_cond_wrapped {
+					f.writeln('')
+				} else {
+					f.write(' ')
+				}
 			}
 			f.write('{')
 			if single_line {

vlib/v/fmt/tests/if_brace_on_newline_expected.vv

@@ -0,0 +1,12 @@
+fn get_typ() Type {
+	{
+		{
+			// The opening brace should be put on a new line here for readability
+			if typ := c.resolve_generic_type(method.return_type, method.generic_names,
+				call_expr.generic_types)
+			{
+				return typ
+			}
+		}
+	}
+}

vlib/v/fmt/tests/if_brace_on_newline_input.vv

@@ -0,0 +1,10 @@
+fn get_typ() Type {
+	{
+		{
+			// The opening brace should be put on a new line here for readability
+			if typ := c.resolve_generic_type(method.return_type, method.generic_names, call_expr.generic_types) {
+				return typ
+			}
+		}
+	}
+}