#5223 added a new variant `JSXElementName::IdentifierReference` for JSX identifiers which are treated as references (e.g. `<Foo>`) as opposed to `JSXElementName::Identifier` which is for lowercase (e.g. `<div>`).
But we were incorrectly categorizing identifiers beginning with `_` or `$` - these should also be treated as references.
(as discussed in https://github.com/oxc-project/oxc/pull/5339#issuecomment-2321037779)
Follow-on after #5223.
JSX identifiers which start with a capital letter are now `JSXElementName::IdentifierReference`s, so no need to check for capitalized `JSXElementName::Identifier`s.
### Before
```
x Flag u is mentioned twice in regular expression literal
,-[1:20]
1 | const a = /\2(.)/uuxig;
: ^
2 | debugger;
`----
x Unexpected flag x in regular expression literal
,-[1:21]
1 | const a = /\2(.)/uuxig;
: ^
2 | debugger;
`----
```
### After
```
x Flag u is mentioned twice in regular expression literal
,-[1:19]
1 | const a = /\2(.)/uuxig;
: ^
2 | debugger;
`----
x Unexpected flag x in regular expression literal
,-[1:20]
1 | const a = /\2(.)/uuxig;
: ^
2 | debugger;
`----
```
Closes#5177
While making this, I noticed an uncaught parse error for accessors: accessors cannot be optional. I'll add a fix for this in an up-stack PR.
This reverts the previous changes to handling labels so that all tests can pass.
This passes all false postivies found in `monitor-oxc` (node_modules/flow-parser/flow_parser.js)
As it turns out this requires less code and produces better diagnostics.
Part of #5008. Make scopes for `ForStatement`, `ForInStatement` and `ForOfStatement` unconditional. i.e. always create a scope, even if there is no lexical binding (e.g. `for (i of a) {}`).
Transform checker check root unresolved references.
The transform checker is now checking pretty much everything it can.
Only fields of `ScopeTree` and `SymbolTable` that it's *not* checking are those which contain `AstNodeId`s, because transformer does not create node IDs at present:
* `ScopeTree::node_ids`
* `SymbolTable::declarations`
* `Reference::node_id`
Checking also only proceeds in "from AST" direction.
i.e. for each `SymbolId` which appears in the AST, we check everything about that symbol. But we *don't* go through all the "rows" in `SymbolTable` and check if there are any extra symbols in the table which aren't in the AST.
Presumably transformer will leave a lot of old symbols lying around in `SymbolTable` (ditto scopes and references). We'd need to add `ScopeFlags::Deleted`, `SymbolFlags::Deleted` and `ReferenceFlags::Deleted` for the transformer to be able to "delete" existing symbols.
Previously was checking that references point to symbols with same name, but not necessarily the same symbol (there could be 2 different symbols with same name).
Pure refactor of transform checker. Store all scope data in `PostTransformChecker` so it doesn't need to be passed around. `SemanticData` contains a full set of all semantic data for semantic pass, so we have 2 instances of it for 1. after transform and 2. rebuilt semantic.
Transformer checker use `SemanticIds` to store collected IDs. `SemanticIds` only contains the IDs, without the `Vec` of errors which is only used temporarily.
