ast: fix bug where fn_signature return wrong str for variadic arg (#9993)

vlib/v/ast/types.v

@@ -1025,8 +1025,12 @@ pub fn (t &Table) fn_signature(func &Fn, opts FnSignatureOpts) string {
 			sb.write_string('$param.name ')
 		}
 		styp := t.type_to_str(typ)
+		if i == func.params.len - 1 && func.is_variadic {
+			sb.write_string('...$styp')
+		} else {
 			sb.write_string('$styp')
 		}
+	}
 	sb.write_string(')')
 	if func.return_type != ast.void_type {
 		sb.write_string(' ${t.type_to_str(func.return_type)}')

vlib/v/checker/tests/fn_args.out

@@ -1,28 +1,35 @@
-vlib/v/checker/tests/fn_args.vv:7:6: error: cannot use `&int` as `byte` in argument 1 to `uu8`
-    5 | fn basic() {
-    6 |     v := 4
-    7 |     uu8(&v)
+vlib/v/checker/tests/fn_args.vv:9:6: error: cannot use `&int` as `byte` in argument 1 to `uu8`
+    7 | fn basic() {
+    8 |     v := 4
+    9 |     uu8(&v)
       |         ~~
-    8 |     arr([5]!)
-    9 |     fun(fn(i &int){})
-vlib/v/checker/tests/fn_args.vv:8:6: error: cannot use `[1]int` as `[]int` in argument 1 to `arr`
-    6 |     v := 4
-    7 |     uu8(&v)
-    8 |     arr([5]!)
+   10 |     arr([5]!)
+   11 |     fun(fn (i &int) {})
+vlib/v/checker/tests/fn_args.vv:10:6: error: cannot use `[1]int` as `[]int` in argument 1 to `arr`
+    8 |     v := 4
+    9 |     uu8(&v)
+   10 |     arr([5]!)
       |         ~~~~
-    9 |     fun(fn(i &int){})
-   10 | }
-vlib/v/checker/tests/fn_args.vv:9:6: error: cannot use `fn (&int)` as `fn (int)` in argument 1 to `fun`
-    7 |     uu8(&v)
-    8 |     arr([5]!)
-    9 |     fun(fn(i &int){})
-      |         ~~~~~~~~~~~~
-   10 | }
-   11 |
+   11 |     fun(fn (i &int) {})
+   12 |     fun(fn (ii ...int) {})
+vlib/v/checker/tests/fn_args.vv:11:6: error: cannot use `fn (&int)` as `fn (int)` in argument 1 to `fun`
+    9 |     uu8(&v)
+   10 |     arr([5]!)
+   11 |     fun(fn (i &int) {})
+      |         ~~~~~~~~~~~~~~
+   12 |     fun(fn (ii ...int) {})
+   13 | }
 Details: ``'s expected fn argument: `` is NOT a pointer, but the passed fn argument: `i` is a pointer
-vlib/v/checker/tests/fn_args.vv:18:4: error: cannot use `int` as `&S1` in argument 1 to `f`
-   16 | fn ptr() {
-   17 |     v := 4
-   18 |     f(v)
+vlib/v/checker/tests/fn_args.vv:12:6: error: cannot use `fn (...int)` as `fn (int)` in argument 1 to `fun`
+   10 |     arr([5]!)
+   11 |     fun(fn (i &int) {})
+   12 |     fun(fn (ii ...int) {})
+      |         ~~~~~~~~~~~~~~~~~
+   13 | }
+   14 |
+vlib/v/checker/tests/fn_args.vv:22:4: error: cannot use `int` as `&S1` in argument 1 to `f`
+   20 | fn ptr() {
+   21 |     v := 4
+   22 |     f(v)
       |       ^
-   19 | }
+   23 | }

vlib/v/checker/tests/fn_args.vv

@@ -1,5 +1,7 @@
 fn uu8(a byte) {}
+
 fn arr(a []int) {}
+
 fn fun(a fn (int)) {}
 
 fn basic() {
@@ -7,10 +9,12 @@ fn basic() {
 	uu8(&v)
 	arr([5]!)
 	fun(fn (i &int) {})
+	fun(fn (ii ...int) {})
 }
 
 struct S1 {
 }
+
 fn f(p &S1) {}
 
 fn ptr() {

vlib/v/checker/tests/struct_field_type_err.out

@@ -0,0 +1,43 @@
+vlib/v/checker/tests/struct_field_type_err.vv:12:3: error: cannot assign to field `n`: expected `int`, not `bool`
+   10 | fn main() {
+   11 |     mut data := Data{
+   12 |         n: true
+      |         ~~~~~~~
+   13 |         b: 0
+   14 |         f1: fn (v ...voidptr) {}
+vlib/v/checker/tests/struct_field_type_err.vv:13:3: error: cannot assign to field `b`: expected `bool`, not `int literal`
+   11 |     mut data := Data{
+   12 |         n: true
+   13 |         b: 0
+      |         ~~~~
+   14 |         f1: fn (v ...voidptr) {}
+   15 |         f2: fn (v voidptr) {}
+vlib/v/checker/tests/struct_field_type_err.vv:14:3: error: cannot assign to field `f1`: expected `fn (voidptr)`, not `fn (...voidptr)`
+   12 |         n: true
+   13 |         b: 0
+   14 |         f1: fn (v ...voidptr) {}
+      |         ~~~~~~~~~~~~~~~~~~~~~~~~
+   15 |         f2: fn (v voidptr) {}
+   16 |         data: true
+Details: ``'s expected fn argument: `` is a pointer, but the passed fn argument: `v` is NOT a pointer
+vlib/v/checker/tests/struct_field_type_err.vv:15:3: error: cannot assign to field `f2`: expected `fn (...voidptr)`, not `fn (voidptr)`
+   13 |         b: 0
+   14 |         f1: fn (v ...voidptr) {}
+   15 |         f2: fn (v voidptr) {}
+      |         ~~~~~~~~~~~~~~~~~~~~~
+   16 |         data: true
+   17 |     }
+Details: ``'s expected fn argument: `` is NOT a pointer, but the passed fn argument: `v` is a pointer
+vlib/v/checker/tests/struct_field_type_err.vv:16:3: error: cannot assign to field `data`: expected `&Data`, not `bool`
+   14 |         f1: fn (v ...voidptr) {}
+   15 |         f2: fn (v voidptr) {}
+   16 |         data: true
+      |         ~~~~~~~~~~
+   17 |     }
+   18 |
+vlib/v/checker/tests/struct_field_type_err.vv:19:11: error: cannot assign to `data.n`: expected `int`, not `bool`
+   17 |     }
+   18 | 
+   19 |     data.n = true
+      |              ~~~~
+   20 | }

vlib/v/checker/tests/struct_field_type_err.vv

@@ -0,0 +1,20 @@
+struct Data {
+mut:
+	n    int
+	b    bool
+	f1   fn (voidptr)
+	f2   fn (...voidptr)
+	data &Data
+}
+
+fn main() {
+	mut data := Data{
+		n: true
+		b: 0
+		f1: fn (v ...voidptr) {}
+		f2: fn (v voidptr) {}
+		data: true
+	}
+
+	data.n = true
+}