Add tests

crates/hir-ty/src/tests/simple.rs

@@ -2733,3 +2733,14 @@ fn f() {
     "#,
     );
 }
+
+#[test]
+fn nested_tuple_index() {
+    check_no_mismatches(
+        r#"
+fn main() {
+    let fld: i32 = ((0,),).0.0;
+}
+"#,
+    );
+}

crates/parser/src/grammar/expressions.rs

@@ -469,6 +469,8 @@ fn method_call_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
 // fn foo() {
 //     x.foo;
 //     x.0.bar;
+//     x.0. bar;
+//     x.0.1;
 //     x.0();
 // }
 fn field_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {

crates/parser/test_data/parser/inline/ok/0011_field_expr.rast

@@ -40,6 +40,39 @@ SOURCE_FILE
               IDENT "bar"
           SEMICOLON ";"
         WHITESPACE "\n    "
+        EXPR_STMT
+          FIELD_EXPR
+            FIELD_EXPR
+              PATH_EXPR
+                PATH
+                  PATH_SEGMENT
+                    NAME_REF
+                      IDENT "x"
+              DOT "."
+              NAME_REF
+                FLOAT_NUMBER_PART "0"
+            DOT "."
+            WHITESPACE " "
+            NAME_REF
+              IDENT "bar"
+          SEMICOLON ";"
+        WHITESPACE "\n    "
+        EXPR_STMT
+          FIELD_EXPR
+            FIELD_EXPR
+              PATH_EXPR
+                PATH
+                  PATH_SEGMENT
+                    NAME_REF
+                      IDENT "x"
+              DOT "."
+              NAME_REF
+                FLOAT_NUMBER_PART "0"
+            DOT "."
+            NAME_REF
+              FLOAT_NUMBER_PART "1"
+          SEMICOLON ";"
+        WHITESPACE "\n    "
         EXPR_STMT
           CALL_EXPR
             FIELD_EXPR

crates/parser/test_data/parser/inline/ok/0011_field_expr.rs

@@ -1,5 +1,7 @@
 fn foo() {
     x.foo;
     x.0.bar;
+    x.0. bar;
+    x.0.1;
     x.0();
 }