Fix parsing of record & list bodies. (#94)

### Brief Description
Change the node structure of the record & list bodies to better
represent the actual syntax of the language. This fixes some bugs as
well as make the syntax more consistent & easier to read.

### Fixes
- TS can't properly detect durantion values in records. It is instead
deteced as integer & a command node that create an error:
```nu
{
    key: 5sec
}
```
- TS can't properly detect when value & key begins & allow invald syntax
with value & key having no space or any separator in between. The
following example is considered valid by TS:
```nu
{
    key: 1536another_key: 8549
}
```

### What is changed
- Records use a new body structure which manages entries & separators in
between. This fixes the separator bugs described above & creates new
nodes that can be used for highlighting & indenting.
- Lists also have their structure changed in the same manner (both
records & list body acts the same in nushell syntax, with exception to
what is actually a record entry ``key: value`` vs a list entry
``value``.
- Record tests are added for the bugs described above. All tests have
been updated with the new node syntax.

### Details
- New function is added to grammar js for general body structure. It
consist of repeated statement all seperated by a mandotory separator,
followed by a final statement with an optional separator.
- This function is applied to the bodies of lists & records with the
corresponding entries.
- List has an added node for the list_entry itself (before it was just
hardcoded into the list rule)
- Separator is added for entries ``[,\s\n\r]``
- Comment is added on top of the code to improve LSP parsing of code
with tsserver (commonly used by other TS projects for grammar.sj)
- Tests are updated with new new node syntax - I've individually checked
the diffs of all tests to make sure they are working as indented
- New test has been added to check if records can accept duration input.
- New test has been added to test if records accept invaild input with
no separator between value & key.

---------

Co-authored-by: CabalCrow <[email protected]>

grammar.js

@@ -1,3 +1,5 @@
+/// <reference types="tree-sitter-cli/dsl" />
+// @ts-check
 module.exports = grammar({
  name: "nu",
 
@@ -1080,25 +1082,28 @@ module.exports = grammar({
  val_list: ($) =>
  seq(
  BRACK().open_brack,
- repeat(
- field(
- "item",
- seq(
- choice(
- $._list_item_expression,
- alias($._unquoted_in_list, $.val_string),
- alias($.short_flag, $.val_string),
- alias($.long_flag, $.val_string),
- alias($._list_item_starts_with_sign, $.val_string),
- ),
- optional(PUNC().comma),
- ),
- ),
- ),
+ optional($.list_body),
  BRACK().close_brack,
  optional($.cell_path),
  ),
 
+ list_body: general_body_rules("entry", "val_entry", "_entry_separator"),
+
+ val_entry: ($) =>
+ prec(
+ 10,
+ field(
+ "item",
+ choice(
+ $._list_item_expression,
+ alias($._unquoted_in_list, $.val_string),
+ alias($.short_flag, $.val_string),
+ alias($.long_flag, $.val_string),
+ alias($._list_item_starts_with_sign, $.val_string),
+ ),
+ ),
+ ),
+
  _list_item_expression: ($) =>
  choice(
  $._value,
@@ -1116,11 +1121,20 @@ module.exports = grammar({
  val_record: ($) =>
  seq(
  BRACK().open_brace,
- repeat(field("entry", $.record_entry)),
+ optional($.record_body),
  BRACK().close_brace,
  optional($.cell_path),
  ),
 
+ record_body: general_body_rules(
+ "entry",
+ "record_entry",
+ "_entry_separator",
+ ),
+
+ _entry_separator: (_$) =>
+ prec(20, token(choice(PUNC().comma, /\s/, /[\r\n]/))),
+
  record_entry: ($) =>
  seq(
  field(
@@ -1147,7 +1161,6 @@ module.exports = grammar({
  alias($.cmd_identifier, $.val_string),
  ),
  ),
- optional(PUNC().comma),
  ),
 
  _record_key: ($) =>
@@ -1278,6 +1291,17 @@ module.exports = grammar({
  },
 });
 
+function general_body_rules(field_name, entry, separator) {
+ return ($) =>
+ prec(
+ 20,
+ seq(
+ repeat(seq(field(field_name, $[entry]), $[separator])), // Normal entries MUST have a separator
+ seq(field(field_name, $[entry]), optional($[separator])), // Final entry may or may not have separator
+ ),
+ );
+}
+
 function parenthesized_body_rules(suffix, terminator) {
  const parenthesized = "_parenthesized";
  return {