Replace LALRPOP parser with hand-written parser

Co-authored-by: Micha Reiser <micha@reiser.io>

crates/ruff_python_parser/src/parser/tests.rs

@@ -0,0 +1,44 @@
+use crate::parser::Parser;
+use crate::token_source::TokenSource;
+use crate::Mode;
+
+mod parser;
+mod suite;
+
+// This is a sanity test for what looks like an ipython directive being
+// assigned to. Although this doesn't actually parse as an assignment
+// statement, but rather, a directive whose value is `foo = 42`.
+#[test]
+fn ok_ipy_escape_command() {
+    use crate::Mode;
+
+    let src = r"!foo = 42";
+    let tokens = crate::lexer::lex(src, Mode::Ipython).collect();
+    let ast = crate::parse_tokens(tokens, src, Mode::Ipython);
+    insta::assert_debug_snapshot!(ast);
+}
+
+// Test that is intentionally ignored by default.
+// Use it for quickly debugging a parser issue.
+#[test]
+#[ignore]
+fn parser_quick_test() {
+    let src = r"if True:
+    1
+    ...
+if x < 1:
+    ...
+else:
+    pass
+
+if a:
+    pass
+elif b:
+    ...
+";
+
+    let tokens = crate::lexer::lex(src, Mode::Module).collect();
+    let ast = Parser::new(src, Mode::Module, TokenSource::new(tokens)).parse_program();
+
+    assert_eq!(&ast.parse_errors, &[]);
+}