1 // Code that generates a test runner to run all the tests in a crate
4 #![allow(unused_imports)]
6 use HasTestSignature::*;
14 use smallvec::{smallvec, SmallVec};
15 use syntax_pos::{DUMMY_SP, NO_EXPANSION, Span, SourceFile, BytePos};
17 use crate::attr::{self, HasAttrs};
18 use crate::source_map::{self, SourceMap, ExpnInfo, MacroAttribute, dummy_spanned, respan};
20 use crate::entry::{self, EntryPointType};
21 use crate::ext::base::{ExtCtxt, Resolver};
22 use crate::ext::build::AstBuilder;
23 use crate::ext::expand::ExpansionConfig;
24 use crate::ext::hygiene::{self, Mark, SyntaxContext};
25 use crate::mut_visit::{*, ExpectOne};
26 use crate::feature_gate::Features;
27 use crate::util::map_in_place::MapInPlace;
28 use crate::parse::{token, ParseSess};
29 use crate::print::pprust;
30 use crate::ast::{self, Ident};
32 use crate::symbol::{self, Symbol, kw, sym};
41 span_diagnostic: &'a errors::Handler,
44 test_cases: Vec<Test>,
45 reexport_test_harness_main: Option<Symbol>,
48 features: &'a Features,
49 test_runner: Option<ast::Path>,
51 // top-level re-export submodule, filled out after folding is finished
52 toplevel_reexport: Option<Ident>,
55 // Traverse the crate, collecting all the test functions, eliding any
56 // existing main functions, and synthesizing a main test harness
57 pub fn modify_for_testing(sess: &ParseSess,
58 resolver: &mut dyn Resolver,
60 krate: &mut ast::Crate,
61 span_diagnostic: &errors::Handler,
62 features: &Features) {
63 // Check for #[reexport_test_harness_main = "some_name"] which
64 // creates a `use __test::main as some_name;`. This needs to be
65 // unconditional, so that the attribute is still marked as used in
67 let reexport_test_harness_main =
68 attr::first_attr_value_str_by_name(&krate.attrs, sym::reexport_test_harness_main);
70 // Do this here so that the test_runner crate attribute gets marked as used
71 // even in non-test builds
72 let test_runner = get_test_runner(span_diagnostic, &krate);
75 generate_test_harness(sess, resolver, reexport_test_harness_main,
76 krate, span_diagnostic, features, test_runner)
80 struct TestHarnessGenerator<'a> {
84 // submodule name, gensym'd identifier for re-exports
85 tested_submods: Vec<(Ident, Ident)>,
88 impl<'a> MutVisitor for TestHarnessGenerator<'a> {
89 fn visit_crate(&mut self, c: &mut ast::Crate) {
90 noop_visit_crate(c, self);
92 // Create a main function to run our tests
94 let unresolved = mk_main(&mut self.cx);
95 self.cx.ext_cx.monotonic_expander().flat_map_item(unresolved).pop().unwrap()
98 c.module.items.push(test_main);
101 fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
103 if ident.name != kw::Invalid {
104 self.cx.path.push(ident);
106 debug!("current path: {}", path_name_i(&self.cx.path));
108 let mut item = i.into_inner();
109 if is_test_case(&item) {
110 debug!("this is a test item");
114 path: self.cx.path.clone(),
116 self.cx.test_cases.push(test);
117 self.tests.push(item.ident);
120 // We don't want to recurse into anything other than mods, since
121 // mods or tests inside of functions will break things
122 if let ast::ItemKind::Mod(mut module) = item.node {
123 let tests = mem::replace(&mut self.tests, Vec::new());
124 let tested_submods = mem::replace(&mut self.tested_submods, Vec::new());
125 noop_visit_mod(&mut module, self);
126 let tests = mem::replace(&mut self.tests, tests);
127 let tested_submods = mem::replace(&mut self.tested_submods, tested_submods);
129 if !tests.is_empty() || !tested_submods.is_empty() {
130 let (it, sym) = mk_reexport_mod(&mut self.cx, item.id, tests, tested_submods);
131 module.items.push(it);
133 if !self.cx.path.is_empty() {
134 self.tested_submods.push((self.cx.path[self.cx.path.len()-1], sym));
136 debug!("pushing nothing, sym: {:?}", sym);
137 self.cx.toplevel_reexport = Some(sym);
140 item.node = ast::ItemKind::Mod(module);
142 if ident.name != kw::Invalid {
148 fn visit_mac(&mut self, _mac: &mut ast::Mac) {
153 /// A folder used to remove any entry points (like fn main) because the harness
154 /// generator will provide its own
155 struct EntryPointCleaner {
156 // Current depth in the ast
160 impl MutVisitor for EntryPointCleaner {
161 fn flat_map_item(&mut self, i: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
163 let item = noop_flat_map_item(i, self).expect_one("noop did something");
166 // Remove any #[main] or #[start] from the AST so it doesn't
167 // clash with the one we're going to add, but mark it as
168 // #[allow(dead_code)] to avoid printing warnings.
169 let item = match entry::entry_point_type(&item, self.depth) {
170 EntryPointType::MainNamed |
171 EntryPointType::MainAttr |
172 EntryPointType::Start =>
173 item.map(|ast::Item {id, ident, attrs, node, vis, span, tokens}| {
174 let allow_ident = Ident::with_empty_ctxt(sym::allow);
175 let dc_nested = attr::mk_nested_word_item(Ident::from_str("dead_code"));
176 let allow_dead_code_item = attr::mk_list_item(DUMMY_SP, allow_ident,
178 let allow_dead_code = attr::mk_attr_outer(DUMMY_SP,
180 allow_dead_code_item);
185 attrs: attrs.into_iter()
187 !attr.check_name(sym::main) && !attr.check_name(sym::start)
189 .chain(iter::once(allow_dead_code))
197 EntryPointType::None |
198 EntryPointType::OtherMain => item,
204 fn visit_mac(&mut self, _mac: &mut ast::Mac) {
209 /// Creates an item (specifically a module) that "pub use"s the tests passed in.
210 /// Each tested submodule will contain a similar reexport module that we will export
211 /// under the name of the original module. That is, `submod::__test_reexports` is
212 /// reexported like so `pub use submod::__test_reexports as submod`.
213 fn mk_reexport_mod(cx: &mut TestCtxt<'_>,
216 tested_submods: Vec<(Ident, Ident)>)
217 -> (P<ast::Item>, Ident) {
218 let super_ = Ident::with_empty_ctxt(kw::Super);
220 let items = tests.into_iter().map(|r| {
221 cx.ext_cx.item_use_simple(DUMMY_SP, dummy_spanned(ast::VisibilityKind::Public),
222 cx.ext_cx.path(DUMMY_SP, vec![super_, r]))
223 }).chain(tested_submods.into_iter().map(|(r, sym)| {
224 let path = cx.ext_cx.path(DUMMY_SP, vec![super_, r, sym]);
225 cx.ext_cx.item_use_simple_(DUMMY_SP, dummy_spanned(ast::VisibilityKind::Public),
229 let reexport_mod = ast::Mod {
235 let name = Ident::from_str("__test_reexports").gensym();
236 let parent = if parent == ast::DUMMY_NODE_ID { ast::CRATE_NODE_ID } else { parent };
237 cx.ext_cx.current_expansion.mark = cx.ext_cx.resolver.get_module_scope(parent);
238 let it = cx.ext_cx.monotonic_expander().flat_map_item(P(ast::Item {
241 id: ast::DUMMY_NODE_ID,
242 node: ast::ItemKind::Mod(reexport_mod),
243 vis: dummy_spanned(ast::VisibilityKind::Public),
251 /// Crawl over the crate, inserting test reexports and the test main function
252 fn generate_test_harness(sess: &ParseSess,
253 resolver: &mut dyn Resolver,
254 reexport_test_harness_main: Option<Symbol>,
255 krate: &mut ast::Crate,
256 sd: &errors::Handler,
258 test_runner: Option<ast::Path>) {
259 // Remove the entry points
260 let mut cleaner = EntryPointCleaner { depth: 0 };
261 cleaner.visit_crate(krate);
263 let mark = Mark::fresh(Mark::root());
265 let mut econfig = ExpansionConfig::default("test".to_string());
266 econfig.features = Some(features);
270 ext_cx: ExtCtxt::new(sess, econfig, resolver),
272 test_cases: Vec::new(),
273 reexport_test_harness_main,
274 // N.B., doesn't consider the value of `--crate-name` passed on the command line.
275 is_libtest: attr::find_crate_name(&krate.attrs)
276 .map(|s| s == sym::test).unwrap_or(false),
277 toplevel_reexport: None,
278 ctxt: SyntaxContext::empty().apply_mark(mark),
283 mark.set_expn_info(ExpnInfo {
286 format: MacroAttribute(sym::test_case),
287 allow_internal_unstable: Some(vec![sym::main, sym::test, sym::rustc_attrs].into()),
288 allow_internal_unsafe: false,
289 local_inner_macros: false,
290 edition: sess.edition,
293 TestHarnessGenerator {
296 tested_submods: Vec::new(),
297 }.visit_crate(krate);
300 /// Craft a span that will be ignored by the stability lint's
301 /// call to source_map's `is_internal` check.
302 /// The expanded code calls some unstable functions in the test crate.
303 fn ignored_span(cx: &TestCtxt<'_>, sp: Span) -> Span {
304 sp.with_ctxt(cx.ctxt)
307 enum HasTestSignature {
309 No(BadTestSignature),
313 enum BadTestSignature {
317 ShouldPanicOnlyWithNoArgs,
320 /// Creates a function item for use as the main function of a test build.
321 /// This function will call the `test_runner` as specified by the crate attribute
322 fn mk_main(cx: &mut TestCtxt<'_>) -> P<ast::Item> {
323 // Writing this out by hand with 'ignored_span':
326 // test::test_main_static(&[..tests]);
328 let sp = ignored_span(cx, DUMMY_SP);
329 let ecx = &cx.ext_cx;
330 let test_id = ecx.ident_of("test").gensym();
332 // test::test_main_static(...)
333 let mut test_runner = cx.test_runner.clone().unwrap_or(
335 test_id, ecx.ident_of("test_main_static")
338 test_runner.span = sp;
340 let test_main_path_expr = ecx.expr_path(test_runner);
341 let call_test_main = ecx.expr_call(sp, test_main_path_expr,
342 vec![mk_tests_slice(cx)]);
343 let call_test_main = ecx.stmt_expr(call_test_main);
346 let main_meta = ecx.meta_word(sp, sym::main);
347 let main_attr = ecx.attribute(sp, main_meta);
349 // extern crate test as test_gensym
350 let test_extern_stmt = ecx.stmt_item(sp, ecx.item(sp,
353 ast::ItemKind::ExternCrate(Some(sym::test))
356 // pub fn main() { ... }
357 let main_ret_ty = ecx.ty(sp, ast::TyKind::Tup(vec![]));
359 // If no test runner is provided we need to import the test crate
360 let main_body = if cx.test_runner.is_none() {
361 ecx.block(sp, vec![test_extern_stmt, call_test_main])
363 ecx.block(sp, vec![call_test_main])
366 let main = ast::ItemKind::Fn(ecx.fn_decl(vec![], ast::FunctionRetTy::Ty(main_ret_ty)),
367 ast::FnHeader::default(),
368 ast::Generics::default(),
371 // Honor the reexport_test_harness_main attribute
372 let main_id = match cx.reexport_test_harness_main {
373 Some(sym) => Ident::new(sym, sp),
374 None => Ident::from_str_and_span("main", sp).gensym(),
379 attrs: vec![main_attr],
380 id: ast::DUMMY_NODE_ID,
382 vis: dummy_spanned(ast::VisibilityKind::Public),
389 fn path_name_i(idents: &[Ident]) -> String {
390 let mut path_name = "".to_string();
391 let mut idents_iter = idents.iter().peekable();
392 while let Some(ident) = idents_iter.next() {
393 path_name.push_str(&ident.as_str());
394 if idents_iter.peek().is_some() {
395 path_name.push_str("::")
401 /// Creates a slice containing every test like so:
402 /// &[path::to::test1, path::to::test2]
403 fn mk_tests_slice(cx: &TestCtxt<'_>) -> P<ast::Expr> {
404 debug!("building test vector from {} tests", cx.test_cases.len());
405 let ref ecx = cx.ext_cx;
407 ecx.expr_vec_slice(DUMMY_SP,
408 cx.test_cases.iter().map(|test| {
409 ecx.expr_addr_of(test.span,
410 ecx.expr_path(ecx.path(test.span, visible_path(cx, &test.path))))
414 /// Creates a path from the top-level __test module to the test via __test_reexports
415 fn visible_path(cx: &TestCtxt<'_>, path: &[Ident]) -> Vec<Ident>{
416 let mut visible_path = vec![];
417 match cx.toplevel_reexport {
418 Some(id) => visible_path.push(id),
420 cx.span_diagnostic.bug("expected to find top-level re-export name, but found None");
423 visible_path.extend_from_slice(path);
427 fn is_test_case(i: &ast::Item) -> bool {
428 attr::contains_name(&i.attrs, sym::rustc_test_marker)
431 fn get_test_runner(sd: &errors::Handler, krate: &ast::Crate) -> Option<ast::Path> {
432 let test_attr = attr::find_by_name(&krate.attrs, sym::test_runner)?;
433 test_attr.meta_item_list().map(|meta_list| {
434 if meta_list.len() != 1 {
435 sd.span_fatal(test_attr.span,
436 "#![test_runner(..)] accepts exactly 1 argument").raise()
438 match meta_list[0].meta_item() {
439 Some(meta_item) if meta_item.is_word() => meta_item.path.clone(),
440 _ => sd.span_fatal(test_attr.span, "`test_runner` argument must be a path").raise()