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Author SHA1 Message Date
Douglas
00709fc5bd
Improves startup time when using std-lib (#13842)
Updated summary for commit
[612e0e2](612e0e2160)
- While folks are welcome to read through the entire comments, the core
information is summarized here.

# Description

This PR drastically improves startup times of Nushell by only parsing a
single submodule of the Standard Library that provides the `banner` and
`pwd` commands. All other Standard Library commands and submodules are
parsed when imported by the user. This cuts startup times by more than
60%.

At the moment, we have stopped adding to `std-lib` because every
addition adds a small amount to the Nushell startup time.
With this change, we should once again be able to allow new
functionality to be added to the Standard Library without it impacting
`nu` startup times.

# User-Facing Changes

* Nushell now starts about 60% faster
* Breaking change: The `dirs` (Shells) aliases will return a warning
message that it will not be auto-loaded in the following release, along
with instructions on how to restore it (and disable the message)
* The `use std <submodule> *` syntax is available for convenience, but
should be avoided in scripts as it parses the entire `std` module and
all other submodules and places it in scope. The correct syntax to
*just* load a submodule is `use std/<submodule> *` (asterisk optional).
The slash is important. This will be documented.
* `use std *` can be used for convenience to load all of the library but
still incurs the full loading-time.
* `std/dirs`: Semi-breaking change. The `dirs` command replaces the
`show` command. This is more in line with the directory-stack
functionality found in other shells. Existing users will not be impacted
by this as the alias (`shells`) remains the same.

* Breaking-change: Technically a breaking change, but probably only
impacts maintainers of `std`. The virtual path for the standard library
has changed. It could previously be imported using its virtual path (and
technically, this would have been the correct way to do it):

  ```nu
  use NU_STDLIB_VIRTUAL_DIR/std
  ```

  The path is now simply `std/`:

  ```nu
  use std
  ```

  All submodules have moved accordingly.
  

# Timings

Comparisons below were made:

* In a temporary, clean config directory using `$env.XDG_CONFIG_HOME =
(mktemp -d)`.
* `nu` was run with a release build
* `nu` was run one time to generate the default `config.nu` (etc.) files
- Otherwise timings would include the user-prompt
* The shell was exited and then restarted several times to get timing
samples

(Note: Old timings based on 0.97 rather than 0.98, but in the range of
being accurate)

| Scenario | `$nu.startup-time` |
| --- | --- |
| 0.97.2
([aaaab8e](aaaab8e070))
Without this PR | 23ms - 24ms |
| This PR with deprecated commands | 9ms - <11ms |
| This PR after deprecated commands are removed in following release |
8ms - <10ms |
| Final PR (remove deprecated), using `--no-std-lib` | 6.1ms to 6.4ms |
| Final PR (remove deprecated), using `--no-config-file` | 3.1ms - 3.6ms
|
| Final PR (remove deprecated), using `--no-config-file --no-std-lib` |
1ms - 1.5ms |

*These last two timings point to the opportunity for further
optimization (see comment in thread below (will link once I write it).*

# Implementation details for future maintenance

* `use std banner` is a ridiculously deceptive call. That call parses
and imports *all* of `std` into scope. Simply replacing it with `use
std/core *` is essentially what saves ~14-15ms. This *only* imports the
submodule with the `banner` and `pwd` commands.

* From the code-comments, the reason that `NU_STDLIB_VIRTUAL_DIR` was
used as a prefix was so that there wouldn't be an issue if a user had a
`./std/mod.nu` in the current directory. This does **not** appear to be
an issue. After removing the prefix, I tested with both a relative
module as well as one in the `$env.NU_LIB_DIRS` path, and in all cases
the *internal* `std` still took precedence.

* By removing the prefix, users can now `use std` (and variants) without
requiring that it already be parsed and in scope.

* In the next release, we'll stop autoloading the `dirs` (shells)
functionality. While this only costs an additional 1-1.5ms, I think it's
better moved to the `config.nu` where the user can optionally remove it.
The main reason is its use of aliases (which have also caused issues) -
The `n`, `p`, and `g` short-commands are valuable real-estate, and users
may want to map these to something else.
  
For this release, there's an `deprecated_dirs` module that is still
autoloaded. As with the top-level commands, use of these will give a
deprecation warning with instructions on how to handle going forward.

To help with this, moved the aliases to their own submodule inside the
`dirs` module.

* Also sneaks in a small change where the top-level `dirs` command is
now the replacement for `dirs show`

* Fixed a double-import of `assert` in `dirs.nu`
* The `show_banner` step is replaced with simply `banner` rather than
re-importing it.

* A `virtual_path` may now be referenced with either a forward-slash or
a backward-slash on Windows. This allows `use std/<submodule>` to work
on all platforms.

# Performance side-notes:

* Future parsing and/or IR improvements should improve performance even
further.
* While the existing load time penalty of `std-lib` was not noticeable
on many systems, Nushell runs on a wide-variety of hardware and OS
platforms. Slower platforms will naturally see a bigger jump in
performance here. For users starting multiple Nushell sessions
frequently (e.g., `tmux`, Zellij, `screen`, et. al.) it is recommended
to keep total startup time (including user configuration) under ~250ms.

# Tests + Formatting

* All tests are green

* Updated tests:
- Removed the test that confirmed that `std` was loaded (since we
don't).
- Removed the `shells` test since it is not autoloaded. Main `dirs.nu`
functionality is tested through `stdlib-test`.
- Many tests assumed that the library was fully loaded, because it was
(even though we didn't intend for it to be). Fixed those tests.
- Tests now import only the necessary submodules (e.g., `use
std/assert`, rather than `use std assert`)
- Some tests *thought* they were loading `std/log`, but were doing so
improperly. This was masked by the now-fixed "load-everything-into-scope
bug". Local CI would pass due the `$env.NU_LOG_<...>` variables being
inherited from the calling process, but would fail in the "clean" GitHub
CI environment. These tests have also been fixed.

 * Added additional tests for the changes

# After Submitting

Will update the Standard Library doc page
2024-10-03 06:28:22 -05:00
Yethal
9ef1203ef9
Implement annotations support in test runner (#9406)
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# Description
Test runner now uses annotations instead of magic function names to pick
up code to run. Additionally skipping tests is now done on annotation
level so skipping and unskipping a test no longer requires changes to
the test code

In order for a function to be picked up by the test runner it needs to
meet following criteria:
* Needs to be private (all exported functions are ignored)
* Needs to contain one of valid annotations (and only the annotation)
directly above the definition, all other comments are ignored

Following are considered valid annotations:
* \# test
* \# test-skip
* \# before-all
* \# before-each
* \# after-each
* \# after-all

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->

# Tests + Formatting
<!--
Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect -A clippy::result_large_err` to check that
you're using the standard code style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- crates/nu-std/tests/run.nu` to run the tests for the
standard library

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->

# After Submitting
<!-- If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
-->
2023-07-02 10:41:33 +02:00
Yethal
0bdc362e13
std: refactor test-runner to no longer require tests to be exported (#9355)
# Description
Test runner now performs following actions in order to run tests:
* Module file is opened
* Public function with random name is added to the source code, this
function calls user-specified private function
* Modified module file is saved under random name in $nu.temp-path
* Modified module file is imported in subprocess, injected function is
called by the test runner
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
* Test functions no longer need to be exported
* test functions no longer need to reside in separate test_ files
* setup and teardown renamed to before-each and after-each respectively
* before-all and after-all functions added that run before all tests in
given module. This matches the behavior of test runners used by other
languages such as JUnit/TestNG or Mocha
# Tests + Formatting

# After Submitting

---------

Co-authored-by: Kamil <skelly37@protonmail.com>
Co-authored-by: amtoine <stevan.antoine@gmail.com>
2023-06-10 20:16:17 +02:00
Astrick
a86f34d0ad
Add zip-into-record to std iter (#9395)
# Description
Adds a new iter feature `zip-into-record` (#9380)

# User-Facing Changes
User can use `[1 2] | iter zip-into-record [3 4]` to create a table `[[1
2]; [3 4]]`

# Tests + Formatting

I noticed trailing spaces in std library that may wish to be cleaned in
the future.

Co-authored-by: amtoine <stevan.antoine@gmail.com>
2023-06-10 20:15:30 +02:00
mike
39e51f1953
add more commands to std iter (#9129)
# Description

this pr adds the following commands to `std iter`
- `iter find-index` -> returns the index of the first element that
matches the predicate or `-1` if none
- `iter flat-map` -> maps a closure to each nested structure and
flattens the result
- `iter zip-with` -> zips two structures and applies a closure to each
of the zips

it also fixes some \*\*very minor\*\* inconsistencies in the module
2023-05-10 19:18:42 +02:00
mike
ed64a44b82
add filter-map command to std iter (#8926)
# Description
as title says
2023-04-19 19:09:10 +02:00
mike
91c01bf6b3
add iter module to standard library (#8899)
# Description
 
this pr introduces an `iter` module
to the standard library.

the module is aimed at extending the filter commands.
2023-04-18 16:01:36 -05:00