2 different SourceTypes needed for parser options, and for in AST

[overlookmotel]

ModuleKind has 3 different options:

oxc/crates/oxc_span/src/source_type/mod.rs

Lines 49 to 62 in d085c2c

	pub enum ModuleKind {
	/// Regular JS script or CommonJS file
	Script = 0,
	/// ES6 Module
	Module = 1,
	/// Consider the file a "module" if ESM syntax is present, or else consider it a "script".
	///
	/// ESM syntax includes `import` statement, `export` statement and `import.meta`.
	///
	/// Note: Dynamic import expression is not ESM syntax.
	///
	/// See <https://babel.dev/docs/options#misc-options>
	Unambiguous = 2,
	}

The "unambiguous" option only makes sense as an input argument to the parser. The parser decides whether it's a script or module during parsing, so a Program is always one or the other, never "unambiguous".

Can we rule out the erroneous "unambiguous" option for Program::source_type by making the existing ModuleKind only "script" or "module", and introducing a separate SourceType to oxc_parser which is only used in ParseOptions?

While we're at it, we could also simplify SourceType by making it just a bitflags byte, or a 1-byte enum.

[Boshen]

This is complicated ...

[Boshen]

While we're at it, we could also simplify SourceType by making it just a bitflags byte, or a 1-byte enum.

This is a huge breaking change because we export Language / ModuleKind / LanguageVariant, serialize them in a certain way.

Program::source_type vs ParserOptions::source_type

This introduces complexity to the project, where we need to distinguish the input and the output. We also need to implement conversions between them so they can be compared.

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The amount of effort for making these changes is a bit of burden. I'll update the documentation instead around unambiguous instead.