feat: 实现 parser crate

crates/oxide_parser/tests/parse_smoke.rs

@@ -0,0 +1,54 @@
+use oxide_parser::Allocator;
+
+#[test]
+fn parse_simple_expression() {
+    let allocator = Allocator::default();
+    let result = oxide_parser::parse(&allocator, "1 + 2");
+    assert!(result.is_ok(), "1+2 should parse successfully");
+}
+
+#[test]
+fn parse_empty_string() {
+    let allocator = Allocator::default();
+    let result = oxide_parser::parse(&allocator, "");
+    assert!(result.is_ok(), "empty string should parse");
+    let program = result.unwrap();
+    assert!(program.body.is_empty(), "empty program should have empty body");
+}
+
+#[test]
+fn parse_function_declaration() {
+    let allocator = Allocator::default();
+    let result = oxide_parser::parse(&allocator, "function foo() { return 42; }");
+    assert!(result.is_ok(), "function declaration should parse");
+    let program = result.unwrap();
+    assert!(!program.body.is_empty(), "program with function should not be empty");
+}
+
+#[test]
+fn parse_syntax_error() {
+    let allocator = Allocator::default();
+    let result = oxide_parser::parse(&allocator, "function(");
+    assert!(result.is_err(), "syntax error should return Err");
+    let errors = result.unwrap_err();
+    assert!(!errors.is_empty(), "syntax error should produce at least one error");
+}
+
+#[test]
+fn parse_variable_declaration() {
+    let allocator = Allocator::default();
+    let result = oxide_parser::parse(&allocator, "var x = 42;");
+    assert!(result.is_ok(), "variable declaration should parse");
+}
+
+#[test]
+fn parse_multiple_statements() {
+    let allocator = Allocator::default();
+    let result = oxide_parser::parse(
+        &allocator,
+        "var a = 1; var b = 2; var c = a + b;",
+    );
+    assert!(result.is_ok(), "multiple statements should parse");
+    let program = result.unwrap();
+    assert_eq!(program.body.len(), 3, "should have 3 statements");
+}