swc_es_parser

swc_es_parser is a bootstrap ECMAScript parser that builds arena-backed nodes from swc_es_ast.

Goals

• Parse source directly into swc_es_ast handles.
• Expose a small parser API (Lexer, Parser, parse_file_as_*).
• Keep parser errors in a crate-local error model while integrating with swc_common diagnostics.

Current Status

• Script/module/program entry points are available.
• Core statements and expression parsing are implemented.
• import/export bootstrap parsing is included.
• Structured for head parsing is available (classic, for..in, for..of).
• JSX parsing supports qualified tag names and reports opening/closing tag mismatches.
• TypeScript parsing builds structured type nodes (function/union/intersection/tuple/array/type-literal/type-args) for type aliases and as assertions.

Fixture Harness

• swc_ecma_parser inputs are reused from crates/swc_ecma_parser/tests.
• swc_es_parser snapshots are stored under crates/swc_es_parser/tests/fixtures.
• Generate or refresh snapshots with:

UPDATE=1 cargo test -p swc_es_parser --test fixture_harness

API Sketch

use swc_common::{input::StringInput, FileName, SourceMap};
use swc_es_parser::{lexer::Lexer, Parser, Syntax};

let cm = SourceMap::default();
let fm = cm.new_source_file(FileName::Custom("a.js".into()).into(), "let a = 1;");
let lexer = Lexer::new(Syntax::default(), StringInput::from(&*fm), None);
let mut parser = Parser::new_from(lexer);
let parsed = parser.parse_program().unwrap();