Snapshot testing is a technique for writing maintainable unit tests.
Unlike usual `assert_eq!` tests, snapshot tests allow
to *automatically* upgrade expected values on test failure.
In a sense, snapshot tests are inline-version of our beloved
UI-tests.
Example:

A particular library we use, `expect_test` provides an `expect!`
macro, which creates a sort of self-updating string literal (by using
`file!` macro). Self-update is triggered by setting `UPDATE_EXPECT`
environmental variable (this info is printed during the test failure).
This library was extracted from rust-analyzer, where we use it for
most of our tests.
There are some other, more popular snapshot testing libraries:
* https://github.com/mitsuhiko/insta
* https://github.com/aaronabramov/k9
The main differences of `expect` are:
* first-class snapshot objects (so, tests can be written as functions,
rather than as macros)
* focus on inline-snapshots (but file snapshots are also supported)
* restricted feature set (only `assert_eq` and `assert_debug_eq`)
* no extra runtime (ie, no `cargo insta`)
See https://github.com/rust-analyzer/rust-analyzer/pull/5101 for a
an extended comparison.
It is unclear if this testing style will stick with rustc in the long
run. At the moment, rustc is mainly tested via integrated UI tests.
But in the library-ified world, unit-tests will become somewhat more
important (that's why use use `rustc_lexer` library-ified library as
an example in this PR). Given that the cost of removal shouldn't be
too high, it probably makes sense to just see if this flies!
Fixes clippy::redundant_static_lifetimes and clippy::toplevel_ref_arg
I also replaced some .expect("") calls with .unwrap()s since there was no message passed by the .expect() anyway.
Capture tokens for Pat used in macro_rules! argument
This extends PR #73293 to handle patterns (Pat). Unlike expressions,
patterns do not support custom attributes, so we only need to capture
tokens during macro_rules! argument parsing.
This extends PR #73293 to handle patterns (Pat). Unlike expressions,
patterns do not support custom attributes, so we only need to capture
tokens during macro_rules! argument parsing.
Cargo update (almost) all the things!
This runs `cargo update` on our dependency tree, bumping numerous crates. See details in the first commit of this PR.
Several updates were held back intentionally; version_check in particular landed a change in behavior in 0.9.2 (arguably a bug fix, but still will be split into a separate PR).
Promote missing_fragment_specifier to hard error
It has been deny_by_default since 2017 (and warned for some time
before that), so it seems reasonable to promote it.
The specific technical motivation to do this now is to remove a field
from `ParseSess` -- it is a global state, and global state makes
extracting libraries annoying.
Closes#40107
treeify depends on an outdated version of clap, which will fail to compile
when we promote missing_fragment_specifier future compat lint to
error (ie, old clap contains code that shouldn't have compiled in the
first place).
Additionally, this crate seem tiny relative to other crates we are
testing here, so it seems like it doesn't provide that much additional
confidence.
The same happens with tokei project, but it is an actively maintained
one, so we can just upgrade it to a version from 2018, where clap was
upgraded.
Add rustc-docs as a component
Previously it was listed as a package but wasn't available in the component
lists in rustup, so wasn't actually installable.
rustc-docs is also only present for x86_64-unknown-linux-gnu. Eventually it'll
also be shipped for aarch64-gnu with current CI configuration, but that builder
isn't quite up and running yet.
We probably want to ship compiler docs for other platforms as well, though, but
this commit doesn't enable that quite yet. A future PR may do so by adding
--enable-compiler-docs to the relevant builders (but it would also need to
decide the set of builders which we'd ship on).
r? @matthiaskrgr
Add sanitizer support on FreeBSD
Restarting #47337. Everything is better now, no more weird llvm problems, well not everything:
Unfortunately, the sanitizers don't have proper support for versioned symbols (https://github.com/google/sanitizers/issues/628), so `libc`'s usage of `stat@FBSD_1.0` and so on explodes, e.g. in calling `std::fs::metadata`.
Building std (now easy thanks to cargo `-Zbuild-std`) and libc with `freebsd12/13` config via the `LIBC_CI=1` env variable is a good workaround…
```
LIBC_CI=1 RUSTFLAGS="-Z sanitizer=address" cargo +san-test -Zbuild-std run --target x86_64-unknown-freebsd --verbose
```
…*except* std won't build because there's no `st_lspare` in the ino64 version of the struct, so an std patch is required:
```diff
--- i/src/libstd/os/freebsd/fs.rs
+++ w/src/libstd/os/freebsd/fs.rs
@@ -66,8 +66,6 @@ pub trait MetadataExt {
fn st_flags(&self) -> u32;
#[stable(feature = "metadata_ext2", since = "1.8.0")]
fn st_gen(&self) -> u32;
- #[stable(feature = "metadata_ext2", since = "1.8.0")]
- fn st_lspare(&self) -> u32;
}
#[stable(feature = "metadata_ext", since = "1.1.0")]
@@ -136,7 +134,4 @@ impl MetadataExt for Metadata {
fn st_flags(&self) -> u32 {
self.as_inner().as_inner().st_flags as u32
}
- fn st_lspare(&self) -> u32 {
- self.as_inner().as_inner().st_lspare as u32
- }
}
```
I guess std could like.. detect that `libc` isn't built for the old ABI, and replace the implementation of `st_lspare` with a panic?
Previously it was listed as a package but wasn't available in the component
lists in rustup, so wasn't actually installable.
rustc-docs is also only present for x86_64-unknown-linux-gnu. Eventually it'll
also be shipped for aarch64-gnu with current CI configuration, but that builder
isn't quite up and running yet.
We probably want to ship compiler docs for other platforms as well, though, but
this commit doesn't enable that quite yet. A future PR may do so by adding
--enable-compiler-docs to the relevant builders (but it would also need to
decide the set of builders which we'd ship on).
merge `as_local_hir_id` with `local_def_id_to_hir_id`
`as_local_hir_id` was defined as just calling `local_def_id_to_hir_id` and I think that having two different ways to call the same method is somewhat confusing.
Don't really care about which of these 2 methods we want to keep.
Does this require an MCP, considering that these methods are fairly frequently used?
Move platform support to the rustc book.
This moves the [Platform Support](https://forge.rust-lang.org/release/platform-support.html) page from the forge to the rustc book. There are several reasons for doing this:
* The forge is not really oriented towards end-users (it mostly contains infrastructure, governance and policy, internal team pages, etc.). This platform support page is useful to user to know which targets are supported.
* This page can now be updated in-sync with any PRs that add or remove a target, or change its status.
* This is now automatically checked on CI to verify the list does not get out of sync. Currently it only checks the presence/absence of an entry, but more sophisticated checks could be added in the future.
I'm not 100% certain this is the best location, but I think it fits. I'd like to see the rustc guide continue to grow, including things like linking information and more platform-specific details.
Update cargo
7 commits in 1653f354644834073d6d2541e27fae94588e685e..ab32ee88dade1b50c77347599e82ca2de3fb8a51
2020-08-04 23:14:37 +0000 to 2020-08-10 17:44:43 +0000
- Build manpage archive deterministically (rust-lang/cargo#8600)
- doc: Qualify GNU licenses in example license field (rust-lang/cargo#8604)
- Fix jobserver_exists test on single-cpu systems (rust-lang/cargo#8598)
- Fix small typo in reference/profiles.md (rust-lang/cargo#8605)
- Default cargo publish to the alt registry if it's the only allowed one (rust-lang/cargo#8571)
- cargo install with specific yanked version gives confusing "not found" error (rust-lang/cargo#8565)
- Fix typo (rust-lang/cargo#8589)
Rollup of 9 pull requests
Successful merges:
- #74521 (older toolchains not valid anymore)
- #74960 (Fix regionck failure when converting Index to IndexMut)
- #75234 (Update asm! documentation in unstable book)
- #75368 (Move to doc links inside the prelude)
- #75371 (Move to doc links inside std/time.rs)
- #75394 (Add a function to `TyCtxt` for computing an `Allocation` for a `static` item's initializer)
- #75395 (Switch to intra-doc links in library/std/src/os/*/fs.rs)
- #75422 (Accept more safety comments)
- #75424 (fix wrong word in documentation)
Failed merges:
r? @ghost
Accept more safety comments
This accepts more `// SAFETY:` comments from `tidy`.
This is done after the current behaviour of requiring text one the same line (because spaces are stripped so the last space never pass if there is no text on the same line) bit me once more in #75066
This could potentially accept empty `// SAFETY:` comments but `tidy` is an internal tool used only here so my reasoning is reviews will catch those.