1 /// The expansion from a test function to the appropriate test struct for libtest
2 /// Ideally, this code would be in libtest but for efficiency and error messages it lives here.
3 use crate::util::{check_builtin_macro_attribute, warn_on_duplicate_attribute};
8 use rustc_ast_pretty::pprust;
9 use rustc_errors::Applicability;
10 use rustc_expand::base::*;
11 use rustc_session::Session;
12 use rustc_span::symbol::{sym, Ident, Symbol};
17 // #[test_case] is used by custom test authors to mark tests
18 // When building for test, it needs to make the item public and gensym the name
19 // Otherwise, we'll omit the item. This behavior means that any item annotated
20 // with #[test_case] is never addressable.
22 // We mark item with an inert attribute "rustc_test_marker" which the test generation
23 // logic will pick up on.
24 pub fn expand_test_case(
25 ecx: &mut ExtCtxt<'_>,
27 meta_item: &ast::MetaItem,
28 anno_item: Annotatable,
29 ) -> Vec<Annotatable> {
30 check_builtin_macro_attribute(ecx, meta_item, sym::test_case);
31 warn_on_duplicate_attribute(&ecx, &anno_item, sym::test_case);
33 if !ecx.ecfg.should_test {
37 let sp = ecx.with_def_site_ctxt(attr_sp);
38 let mut item = anno_item.expect_item();
39 item = item.map(|mut item| {
40 item.vis = ast::Visibility {
42 kind: ast::VisibilityKind::Public,
45 item.ident.span = item.ident.span.with_ctxt(sp.ctxt());
46 item.attrs.push(ecx.attribute(ecx.meta_word(sp, sym::rustc_test_marker)));
50 return vec![Annotatable::Item(item)];
56 meta_item: &ast::MetaItem,
58 ) -> Vec<Annotatable> {
59 check_builtin_macro_attribute(cx, meta_item, sym::test);
60 warn_on_duplicate_attribute(&cx, &item, sym::test);
61 expand_test_or_bench(cx, attr_sp, item, false)
67 meta_item: &ast::MetaItem,
69 ) -> Vec<Annotatable> {
70 check_builtin_macro_attribute(cx, meta_item, sym::bench);
71 warn_on_duplicate_attribute(&cx, &item, sym::bench);
72 expand_test_or_bench(cx, attr_sp, item, true)
75 pub fn expand_test_or_bench(
80 ) -> Vec<Annotatable> {
81 // If we're not in test configuration, remove the annotated item
82 if !cx.ecfg.should_test {
86 let (item, is_stmt) = match item {
87 Annotatable::Item(i) => (i, false),
88 Annotatable::Stmt(stmt) if matches!(stmt.kind, ast::StmtKind::Item(_)) => {
89 // FIXME: Use an 'if let' guard once they are implemented
90 if let ast::StmtKind::Item(i) = stmt.into_inner().kind {
99 "`#[test]` attribute is only allowed on non associated functions",
106 // Note: non-associated fn items are already handled by `expand_test_or_bench`
107 if !matches!(item.kind, ast::ItemKind::Fn(_)) {
108 let diag = &cx.sess.parse_sess.span_diagnostic;
109 let msg = "the `#[test]` attribute may only be used on a non-associated function";
110 let mut err = match item.kind {
111 // These were a warning before #92959 and need to continue being that to avoid breaking
112 // stable user code (#94508).
113 ast::ItemKind::MacCall(_) => diag.struct_span_warn(attr_sp, msg),
114 // `.forget_guarantee()` needed to get these two arms to match types. Because of how
115 // locally close the `.emit()` call is I'm comfortable with it, but if it can be
116 // reworked in the future to not need it, it'd be nice.
117 _ => diag.struct_span_err(attr_sp, msg).forget_guarantee(),
119 err.span_label(attr_sp, "the `#[test]` macro causes a a function to be run on a test and has no effect on non-functions")
120 .span_label(item.span, format!("expected a non-associated function, found {} {}", item.kind.article(), item.kind.descr()))
121 .span_suggestion(attr_sp, "replace with conditional compilation to make the item only exist when tests are being run", "#[cfg(test)]", Applicability::MaybeIncorrect)
124 return vec![Annotatable::Item(item)];
127 // has_*_signature will report any errors in the type so compilation
128 // will fail. We shouldn't try to expand in this case because the errors
129 // would be spurious.
130 if (!is_bench && !has_test_signature(cx, &item))
131 || (is_bench && !has_bench_signature(cx, &item))
133 return vec![Annotatable::Item(item)];
136 let (sp, attr_sp) = (cx.with_def_site_ctxt(item.span), cx.with_def_site_ctxt(attr_sp));
138 let test_id = Ident::new(sym::test, attr_sp);
140 // creates test::$name
141 let test_path = |name| cx.path(sp, vec![test_id, Ident::from_str_and_span(name, sp)]);
143 // creates test::ShouldPanic::$name
144 let should_panic_path = |name| {
149 Ident::from_str_and_span("ShouldPanic", sp),
150 Ident::from_str_and_span(name, sp),
155 // creates test::TestType::$name
156 let test_type_path = |name| {
161 Ident::from_str_and_span("TestType", sp),
162 Ident::from_str_and_span(name, sp),
167 // creates $name: $expr
168 let field = |name, expr| cx.field_imm(sp, Ident::from_str_and_span(name, sp), expr);
170 let test_fn = if is_bench {
171 // A simple ident for a lambda
172 let b = Ident::from_str_and_span("b", attr_sp);
176 cx.expr_path(test_path("StaticBenchFn")),
178 // |b| self::test::assert_test_result(
183 cx.expr_path(test_path("assert_test_result")),
185 // super::$test_fn(b)
188 cx.expr_path(cx.path(sp, vec![item.ident])),
189 vec![cx.expr_ident(sp, b)],
200 cx.expr_path(test_path("StaticTestFn")),
205 // test::assert_test_result(
208 cx.expr_path(test_path("assert_test_result")),
211 cx.expr_call(sp, cx.expr_path(cx.path(sp, vec![item.ident])), vec![]), // )
219 let mut test_const = cx.item(
221 Ident::new(item.ident.name, sp),
224 cx.attribute(attr::mk_list_item(
225 Ident::new(sym::cfg, attr_sp),
226 vec![attr::mk_nested_word_item(Ident::new(sym::test, attr_sp))],
228 // #[rustc_test_marker]
229 cx.attribute(cx.meta_word(attr_sp, sym::rustc_test_marker)),
231 // const $ident: test::TestDescAndFn =
232 ast::ItemKind::Const(
233 ast::Defaultness::Final,
234 cx.ty(sp, ast::TyKind::Path(None, test_path("TestDescAndFn"))),
235 // test::TestDescAndFn {
239 test_path("TestDescAndFn"),
241 // desc: test::TestDesc {
246 test_path("TestDesc"),
248 // name: "path::to::test"
253 cx.expr_path(test_path("StaticTestName")),
256 Symbol::intern(&item_path(
257 // skip the name of the root module
258 &cx.current_expansion.module.mod_path[1..],
264 // ignore: true | false
267 cx.expr_bool(sp, should_ignore(&cx.sess, &item)),
269 // ignore_message: Some("...") | None
272 if let Some(msg) = should_ignore_message(cx, &item) {
273 cx.expr_some(sp, cx.expr_str(sp, msg))
278 // compile_fail: true | false
279 field("compile_fail", cx.expr_bool(sp, false)),
280 // no_run: true | false
281 field("no_run", cx.expr_bool(sp, false)),
285 match should_panic(cx, &item) {
286 // test::ShouldPanic::No
288 cx.expr_path(should_panic_path("No"))
290 // test::ShouldPanic::Yes
291 ShouldPanic::Yes(None) => {
292 cx.expr_path(should_panic_path("Yes"))
294 // test::ShouldPanic::YesWithMessage("...")
295 ShouldPanic::Yes(Some(sym)) => cx.expr_call(
297 cx.expr_path(should_panic_path("YesWithMessage")),
298 vec![cx.expr_str(sp, sym)],
305 match test_type(cx) {
306 // test::TestType::UnitTest
307 TestType::UnitTest => {
308 cx.expr_path(test_type_path("UnitTest"))
310 // test::TestType::IntegrationTest
311 TestType::IntegrationTest => {
312 cx.expr_path(test_type_path("IntegrationTest"))
314 // test::TestPath::Unknown
315 TestType::Unknown => {
316 cx.expr_path(test_type_path("Unknown"))
324 // testfn: test::StaticTestFn(...) | test::StaticBenchFn(...)
325 field("testfn", test_fn), // }
331 test_const = test_const.map(|mut tc| {
332 tc.vis.kind = ast::VisibilityKind::Public;
337 let test_extern = cx.item(sp, test_id, vec![], ast::ItemKind::ExternCrate(None));
339 tracing::debug!("synthetic test item:\n{}\n", pprust::item_to_string(&test_const));
343 // Access to libtest under a hygienic name
344 Annotatable::Stmt(P(cx.stmt_item(sp, test_extern))),
345 // The generated test case
346 Annotatable::Stmt(P(cx.stmt_item(sp, test_const))),
348 Annotatable::Stmt(P(cx.stmt_item(sp, item))),
352 // Access to libtest under a hygienic name
353 Annotatable::Item(test_extern),
354 // The generated test case
355 Annotatable::Item(test_const),
357 Annotatable::Item(item),
362 fn item_path(mod_path: &[Ident], item_ident: &Ident) -> String {
365 .chain(iter::once(item_ident))
366 .map(|x| x.to_string())
367 .collect::<Vec<String>>()
376 fn should_ignore(sess: &Session, i: &ast::Item) -> bool {
377 sess.contains_name(&i.attrs, sym::ignore)
380 fn should_ignore_message(cx: &ExtCtxt<'_>, i: &ast::Item) -> Option<Symbol> {
381 match cx.sess.find_by_name(&i.attrs, sym::ignore) {
383 match attr.meta_item_list() {
384 // Handle #[ignore(bar = "foo")]
386 // Handle #[ignore] and #[ignore = "message"]
387 None => attr.value_str(),
394 fn should_panic(cx: &ExtCtxt<'_>, i: &ast::Item) -> ShouldPanic {
395 match cx.sess.find_by_name(&i.attrs, sym::should_panic) {
397 let sd = &cx.sess.parse_sess.span_diagnostic;
399 match attr.meta_item_list() {
400 // Handle #[should_panic(expected = "foo")]
404 .find(|mi| mi.has_name(sym::expected))
405 .and_then(|mi| mi.meta_item())
406 .and_then(|mi| mi.value_str());
407 if list.len() != 1 || msg.is_none() {
410 "argument must be of the form: \
411 `expected = \"error message\"`",
414 "errors in this attribute were erroneously \
415 allowed and will become a hard error in a \
419 ShouldPanic::Yes(None)
421 ShouldPanic::Yes(msg)
424 // Handle #[should_panic] and #[should_panic = "expected"]
425 None => ShouldPanic::Yes(attr.value_str()),
428 None => ShouldPanic::No,
438 /// Attempts to determine the type of test.
439 /// Since doctests are created without macro expanding, only possible variants here
440 /// are `UnitTest`, `IntegrationTest` or `Unknown`.
441 fn test_type(cx: &ExtCtxt<'_>) -> TestType {
442 // Root path from context contains the topmost sources directory of the crate.
443 // I.e., for `project` with sources in `src` and tests in `tests` folders
444 // (no matter how many nested folders lie inside),
445 // there will be two different root paths: `/project/src` and `/project/tests`.
446 let crate_path = cx.root_path.as_path();
448 if crate_path.ends_with("src") {
449 // `/src` folder contains unit-tests.
451 } else if crate_path.ends_with("tests") {
452 // `/tests` folder contains integration tests.
453 TestType::IntegrationTest
455 // Crate layout doesn't match expected one, test type is unknown.
460 fn has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
461 let has_should_panic_attr = cx.sess.contains_name(&i.attrs, sym::should_panic);
462 let sd = &cx.sess.parse_sess.span_diagnostic;
463 if let ast::ItemKind::Fn(box ast::Fn { ref sig, ref generics, .. }) = i.kind {
464 if let ast::Unsafe::Yes(span) = sig.header.unsafety {
465 sd.struct_span_err(i.span, "unsafe functions cannot be used for tests")
466 .span_label(span, "`unsafe` because of this")
470 if let ast::Async::Yes { span, .. } = sig.header.asyncness {
471 sd.struct_span_err(i.span, "async functions cannot be used for tests")
472 .span_label(span, "`async` because of this")
477 // If the termination trait is active, the compiler will check that the output
478 // type implements the `Termination` trait as `libtest` enforces that.
479 let has_output = match sig.decl.output {
480 ast::FnRetTy::Default(..) => false,
481 ast::FnRetTy::Ty(ref t) if t.kind.is_unit() => false,
485 if !sig.decl.inputs.is_empty() {
486 sd.span_err(i.span, "functions used as tests can not have any arguments");
490 match (has_output, has_should_panic_attr) {
492 sd.span_err(i.span, "functions using `#[should_panic]` must return `()`");
496 if !generics.params.is_empty() {
497 sd.span_err(i.span, "functions used as tests must have signature fn() -> ()");
506 // should be unreachable because `is_test_fn_item` should catch all non-fn items
511 fn has_bench_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
512 let has_sig = if let ast::ItemKind::Fn(box ast::Fn { ref sig, .. }) = i.kind {
513 // N.B., inadequate check, but we're running
514 // well before resolve, can't get too deep.
515 sig.decl.inputs.len() == 1
521 cx.sess.parse_sess.span_diagnostic.span_err(
523 "functions used as benches must have \
524 signature `fn(&mut Bencher) -> impl Termination`",