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!
Add some timing info to rustdoc
There are various improvements, but the main one is to time each pass
that rustdoc performs (`rustdoc::passes`).
Before, these were the top five timings for `cargo doc` on the cargo
repository:
```
+---------------------------------+-----------+-----------------+----------+------------+
| Item | Self time | % of total time | Time | Item count |
+---------------------------------+-----------+-----------------+----------+------------+
| <unknown> | 854.70ms | 20.888 | 2.47s | 744823 |
+---------------------------------+-----------+-----------------+----------+------------+
| expand_crate | 795.29ms | 19.436 | 848.00ms | 1 |
+---------------------------------+-----------+-----------------+----------+------------+
| metadata_decode_entry | 256.73ms | 6.274 | 279.49ms | 518344 |
+---------------------------------+-----------+-----------------+----------+------------+
| resolve_crate | 240.56ms | 5.879 | 242.86ms | 1 |
+---------------------------------+-----------+-----------------+----------+------------+
| hir_lowering | 146.79ms | 3.587 | 146.79ms | 1 |
+---------------------------------+-----------+-----------------+----------+------------+
```
Now the timings are:
```
+---------------------------------+-----------+-----------------+----------+------------+
| Item | Self time | % of total time | Time | Item count |
+---------------------------------+-----------+-----------------+----------+------------+
| <unknown> | 1.40s | 22.662 | 3.73s | 771430 |
+---------------------------------+-----------+-----------------+----------+------------+
| collect-trait-impls | 1.34s | 21.672 | 2.87s | 1 |
+---------------------------------+-----------+-----------------+----------+------------+
| expand_crate | 1.21s | 19.577 | 1.28s | 1 |
+---------------------------------+-----------+-----------------+----------+------------+
| build extern trait impl | 704.66ms | 11.427 | 1.07s | 21893 |
+---------------------------------+-----------+-----------------+----------+------------+
| metadata_decode_entry | 354.84ms | 5.754 | 391.81ms | 544919 |
+---------------------------------+-----------+-----------------+----------+------------+
```
The goal is to help me debug regressions like https://github.com/rust-lang/rust/pull/74518#issuecomment-661498214 (currently I have _no_ idea what could have gone wrong).
r? @eddyb or @Mark-Simulacrum
* Don't say that Unpin is used to prevent moves, because it is used
to *allow* moves
* Be more precise about kindedness of things, it is
`Pin<Pointer<Data>>`, rather than just `Pin<Pointer>`.
This commit adjusts the naming of various lang items so that they are
consistent and don't include prefixes containing the target or
"LangItem". In addition, lang item variants are no longer exported from
the `lang_items` module.
Signed-off-by: David Wood <david@davidtw.co>
Report an ambiguity if both modules and primitives are in scope for intra-doc links
Closes https://github.com/rust-lang/rust/issues/75381
- Add a new `prim@` disambiguator, since both modules and primitives are in the same namespace
- Refactor `report_ambiguity` into a closure
Additionally, I noticed that rustdoc would previously allow `[struct@char]` if `char` resolved to a primitive (not if it had a DefId). I fixed that and added a test case.
I also need to update libstd to use `prim@char` instead of `type@char`. If possible I would also like to refactor `ambiguity_error` to use `Disambiguator` instead of its own hand-rolled match - that ran into issues with `prim@` (I updated one and not the other) and it would be better for them to be in sync.
The 'freestanding' module was only ever used for AVR. It was an
unnecessary layer of abstraction. This commit merges the
'freestanding_base' module into 'avr_gnu_base'.
In general, linking with libc is not required, only libgcc is needed.
As suggested in the code review, a better option for libc support is by
building it into rust-lang/libc directly.
This also removes the '-Os' argument to the linker, which is a NOP.
The `avr-unknown-unknown` target has never worked correctly, always trying to invoke
the host linker and failing. It aimed to be a mirror of AVR-GCC's
default handling of the `avr-unknown-unknown' triple (assume bare
minimum chip features, silently skip linking runtime libraries, etc).
This behaviour is broken-by-default as it will cause a miscompiled executable
when flashed.
This patch improves the AVR builtin target specifications to instead
expose only a 'avr-unknown-gnu-atmega328' target. This target system is
`gnu`, as it uses the AVR-GCC frontend along with avr-binutils. The
target triple ABI is 'atmega328'.
In the future, it should be possible to replace the dependency on
AVR-GCC and binutils by using the in-progress AVR LLD and compiler-rt support.
Perhaps at that point it would make sense to add an
'avr-unknown-unknown-atmega328' target as a better default when
implemented.
There is no current intention to add in-tree AVR target specifications for other
AVR microcontrollers - this one can serve as a reference implementation
for other devices via `rustc --print target-spec-json
avr-unknown-gnu-atmega328p`.
There should be no users of the existing 'avr-unknown-unknown' Rust
target as a custom target specification JSON has always been
recommended, and the avr-unknown-unknown target could never pass the
linking step anyway.
Use allow(unused_imports) instead of cfg(doc) for imports used only for intra-doc links
This prevents links from breaking when items are re-exported in a
different crate and the original isn't being documented.
Spotted in https://github.com/rust-lang/rust/pull/75832#discussion_r475275837 (thanks ollie!)
r? @ollie27
publish-toolstate: show more context on HTTP error
The default display for HTTPError in Python does not include the request body. For GitHub API, the body includes more details about the error (like rate limiting). This could help diagnosing errors like this: https://github.com/rust-lang/rust/pull/75815#issuecomment-678798158
Fix typo in documentation of i32 wrapping_abs()
Hi!
I was reading through the std library docs and noticed that this section flowed a bit oddly; comparing it against https://doc.rust-lang.org/std/primitive.i32.html#method.wrapping_div and https://doc.rust-lang.org/std/primitive.i32.html#method.wrapping_neg , I noticed that those two pieces of documentation used a semicolon here.
This is my first time submitting a PR to this repo. Am I doing this right? Are tiny typo-fix PRs like this worth submitting, or are they not a good use of time?
Thank you!
Switch to intra-doc links in `std::macros`
Part of #75080.
---
* Switch to intra-doc links in `std::macros`
* Fix typo in module docs
* Link to `std::io::stderr` instead of `std::io::Stderr` to match the
link text
* Link to `std::io::stdout`
---
@rustbot modify labels: A-intra-doc-links T-doc T-rustdoc
