bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir_def/src/macro_expansion_tests.rs')
-rw-r--r--crates/hir_def/src/macro_expansion_tests.rs87
1 files changed, 87 insertions, 0 deletions
diff --git a/crates/hir_def/src/macro_expansion_tests.rs b/crates/hir_def/src/macro_expansion_tests.rs
new file mode 100644
index 0000000000..861a059a14
--- /dev/null
+++ b/crates/hir_def/src/macro_expansion_tests.rs
@@ -0,0 +1,87 @@
+//! This module contains tests for macro expansion. Effectively, it covers `tt`,
+//! `mbe`, `proc_macro_api` and `hir_expand` crates. This might seem like a
+//! wrong architecture at the first glance, but is intentional.
+//!
+//! Physically, macro expansion process is intertwined with name resolution. You
+//! can not expand *just* the syntax. So, to be able to write integration tests
+//! of the "expand this code please" form, we have to do it after name
+//! resolution. That is, in this crate. We *could* fake some dependencies and
+//! write unit-tests (in fact, we used to do that), but that makes tests brittle
+//! and harder to understand.
+
+use std::ops::Range;
+
+use base_db::{fixture::WithFixture, SourceDatabase};
+use expect_test::{expect, Expect};
+use hir_expand::{db::AstDatabase, InFile, MacroFile};
+use stdx::format_to;
+use syntax::{ast, AstNode};
+
+use crate::{
+ db::DefDatabase, nameres::ModuleSource, resolver::HasResolver, test_db::TestDB, AsMacroCall,
+};
+
+fn check(ra_fixture: &str, expect: Expect) {
+ let db = TestDB::with_files(ra_fixture);
+ let krate = db.crate_graph().iter().next().unwrap();
+ let def_map = db.crate_def_map(krate);
+ let local_id = def_map.root();
+ let module = def_map.module_id(local_id);
+ let resolver = module.resolver(&db);
+ let source = def_map[local_id].definition_source(&db);
+ let source_file = match source.value {
+ ModuleSource::SourceFile(it) => it,
+ ModuleSource::Module(_) | ModuleSource::BlockExpr(_) => panic!(),
+ };
+
+ let mut expansions = Vec::new();
+ for macro_call in source_file.syntax().descendants().filter_map(ast::MacroCall::cast) {
+ let macro_call = InFile::new(source.file_id, &macro_call);
+ let macro_call_id = macro_call
+ .as_call_id_with_errors(
+ &db,
+ krate,
+ |path| resolver.resolve_path_as_macro(&db, &path),
+ &mut |err| panic!("{}", err),
+ )
+ .unwrap()
+ .unwrap();
+ let macro_file = MacroFile { macro_call_id };
+ let expansion_result = db.parse_macro_expansion(macro_file);
+ expansions.push((macro_call.value.clone(), expansion_result));
+ }
+
+ let mut expanded_text = source_file.to_string();
+ for (call, exp) in expansions.into_iter().rev() {
+ let mut expn_text = String::new();
+ if let Some(err) = exp.err {
+ format_to!(expn_text, "/* error: {} */", err);
+ }
+ if let Some((parse, _token_map)) = exp.value {
+ format_to!(expn_text, "{}", parse.syntax_node());
+ }
+ let range = call.syntax().text_range();
+ let range: Range<usize> = range.into();
+ expanded_text.replace_range(range, &expn_text)
+ }
+
+ expect.assert_eq(&expanded_text);
+}
+
+#[test]
+fn test_expand_rule() {
+ check(
+ r#"
+macro_rules! m {
+ ($($i:ident);*) => ($i)
+}
+m!{a}
+"#,
+ expect![[r#"
+macro_rules! m {
+ ($($i:ident);*) => ($i)
+}
+/* error: expected simple binding, found nested binding `i` */
+"#]],
+ );
+}