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<!-- if this PR closes one or more issues, you can automatically link the PR with them by using one of the [*linking keywords*](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword), e.g. - this PR should close #xxxx - fixes #xxxx you can also mention related issues, PRs or discussions! --> # Description <!-- Thank you for improving Nushell. Please, check our [contributing guide](../CONTRIBUTING.md) and talk to the core team before making major changes. Description of your pull request goes here. **Provide examples and/or screenshots** if your changes affect the user experience. --> This PR adds type checking of all command input types at run-time. Generally, these errors should be caught by the parser, but sometimes we can't know the type of a value at parse-time. The simplest example is using the `echo` command, which has an output type of `any`, so prefixing a literal with `echo` will bypass parse-time type checking. Before this PR, each command has to individually check its input types. This can result in scenarios where the input/output types don't match the actual command behavior. This can cause valid usage with an non-`any` type to become a parse-time error if a command is missing that type in its pipeline input/output (`drop nth` and `history import` do this before this PR). Alternatively, a command may not list a type in its input/output types, but doesn't actually reject that type in its code, which can have unintended side effects (`get` does this on an empty pipeline input, and `sort` used to before #13154). After this PR, the type of the pipeline input is checked to ensure it matches one of the input types listed in the proceeding command's input/output types. While each of the issues in the "before this PR" section could be addressed with each command individually, this PR solves this issue for _all_ commands. **This will likely cause some breakage**, as some commands have incorrect input/output types, and should be adjusted. Also, some scripts may have erroneous usage of commands. In writing this PR, I discovered that `toolkit.nu` was passing `null` values to `str join`, which doesn't accept nothing types (if folks think it should, we can adjust it in this PR or in a different PR). I found some issues in the standard library and its tests. I also found that carapace's vendor script had an incorrect chaining of `get -i`: ```nushell let expanded_alias = (scope aliases | where name == $spans.0 | get -i 0 | get -i expansion) ``` Before this PR, if the `get -i 0` ever actually did evaluate to `null`, the second `get` invocation would error since `get` doesn't operate on `null` values. After this PR, this is immediately a run-time error, alerting the user to the problematic code. As a side note, we'll need to PR this fix (`get -i 0 | get -i expansion` -> `get -i 0.expansion`) to carapace. A notable exception to the type checking is commands with input type of `nothing -> <type>`. In this case, any input type is allowed. This allows piping values into the command without an error being thrown. For example, `123 | echo $in` would be an error without this exception. Additionally, custom types bypass type checking (I believe this also happens during parsing, but not certain) I added a `is_subtype` method to `Value` and `PipelineData`. It functions slightly differently than `get_type().is_subtype()`, as noted in the doccomments. Notably, it respects structural typing of lists and tables. For example, the type of a value `[{a: 123} {a: 456, b: 789}]` is a subtype of `table<a: int>`, whereas the type returned by `Value::get_type` is a `list<any>`. Similarly, `PipelineData` has some special handling for `ListStream`s and `ByteStream`s. The latter was needed for this PR to work properly with external commands. Here's some examples. Before: ```nu 1..2 | drop nth 1 Error: nu::parser::input_type_mismatch × Command does not support range input. ╭─[entry #9:1:8] 1 │ 1..2 | drop nth 1 · ────┬─── · ╰── command doesn't support range input ╰──── echo 1..2 | drop nth 1 # => ╭───┬───╮ # => │ 0 │ 1 │ # => ╰───┴───╯ ``` After this PR, I've adjusted `drop nth`'s input/output types to accept range input. Before this PR, zip accepted any value despite not being listed in its input/output types. This caused different behavior depending on if you triggered a parse error or not: ```nushell 1 | zip [2] # => Error: nu::parser::input_type_mismatch # => # => × Command does not support int input. # => ╭─[entry #3:1:5] # => 1 │ 1 | zip [2] # => · ─┬─ # => · ╰── command doesn't support int input # => ╰──── echo 1 | zip [2] # => ╭───┬───────────╮ # => │ 0 │ ╭───┬───╮ │ # => │ │ │ 0 │ 1 │ │ # => │ │ │ 1 │ 2 │ │ # => │ │ ╰───┴───╯ │ # => ╰───┴───────────╯ ``` After this PR, it works the same in both cases. For cases like this, if we do decide we want `zip` or other commands to accept any input value, then we should explicitly add that to the input types. ```nushell 1 | zip [2] # => Error: nu::parser::input_type_mismatch # => # => × Command does not support int input. # => ╭─[entry #3:1:5] # => 1 │ 1 | zip [2] # => · ─┬─ # => · ╰── command doesn't support int input # => ╰──── echo 1 | zip [2] # => Error: nu:🐚:only_supports_this_input_type # => # => × Input type not supported. # => ╭─[entry #14:2:6] # => 2 │ echo 1 | zip [2] # => · ┬ ─┬─ # => · │ ╰── only list<any> and range input data is supported # => · ╰── input type: int # => ╰──── ``` # User-Facing Changes <!-- List of all changes that impact the user experience here. This helps us keep track of breaking changes. --> **Breaking change**: The type of a command's input is now checked against the input/output types of that command at run-time. While these errors should mostly be caught at parse-time, in cases where they can't be detected at parse-time they will be caught at run-time instead. This applies to both internal commands and custom commands. Example function and corresponding parse-time error (same before and after PR): ```nushell def foo []: int -> nothing { print $"my cool int is ($in)" } 1 | foo # => my cool int is 1 "evil string" | foo # => Error: nu::parser::input_type_mismatch # => # => × Command does not support string input. # => ╭─[entry #16:1:17] # => 1 │ "evil string" | foo # => · ─┬─ # => · ╰── command doesn't support string input # => ╰──── # => ``` Before: ```nu echo "evil string" | foo # => my cool int is evil string ``` After: ```nu echo "evil string" | foo # => Error: nu:🐚:only_supports_this_input_type # => # => × Input type not supported. # => ╭─[entry #17:1:6] # => 1 │ echo "evil string" | foo # => · ──────┬────── ─┬─ # => · │ ╰── only int input data is supported # => · ╰── input type: string # => ╰──── ``` Known affected internal commands which erroneously accepted any type: * `str join` * `zip` * `reduce` # 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` to check that you're using the standard code style - `cargo test --workspace` to check that all tests pass (on Windows make sure to [enable developer mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging)) - `cargo run -- -c "use toolkit.nu; toolkit test stdlib"` 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 > ``` --> - 🟢 `toolkit fmt` - 🟢 `toolkit clippy` - 🟢 `toolkit test` - 🟢 `toolkit test stdlib` # 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. --> * Play whack-a-mole with the commands and scripts this will inevitably break |
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.. | ||
assignment | ||
base | ||
bytes | ||
conversions | ||
database | ||
date | ||
debug | ||
hash_ | ||
math | ||
move_ | ||
network | ||
path | ||
platform | ||
query | ||
random | ||
skip | ||
str_ | ||
take | ||
url | ||
alias.rs | ||
all.rs | ||
any.rs | ||
append.rs | ||
break_.rs | ||
cal.rs | ||
cd.rs | ||
chunk_by.rs | ||
chunks.rs | ||
compact.rs | ||
complete.rs | ||
config_env_default.rs | ||
config_nu_default.rs | ||
continue_.rs | ||
debug_info.rs | ||
def.rs | ||
default.rs | ||
detect_columns.rs | ||
do_.rs | ||
drop.rs | ||
du.rs | ||
each.rs | ||
echo.rs | ||
empty.rs | ||
error_make.rs | ||
every.rs | ||
exec.rs | ||
export_def.rs | ||
fill.rs | ||
filter.rs | ||
find.rs | ||
first.rs | ||
flatten.rs | ||
for_.rs | ||
format.rs | ||
generate.rs | ||
get.rs | ||
glob.rs | ||
griddle.rs | ||
group_by.rs | ||
headers.rs | ||
help.rs | ||
histogram.rs | ||
ignore.rs | ||
insert.rs | ||
inspect.rs | ||
interleave.rs | ||
into_datetime.rs | ||
into_filesize.rs | ||
into_int.rs | ||
join.rs | ||
last.rs | ||
length.rs | ||
let_.rs | ||
lines.rs | ||
loop_.rs | ||
ls.rs | ||
match_.rs | ||
merge_deep.rs | ||
merge.rs | ||
mktemp.rs | ||
mod.rs | ||
mut_.rs | ||
nu_check.rs | ||
open.rs | ||
par_each.rs | ||
parse.rs | ||
prepend.rs | ||
print.rs | ||
range.rs | ||
redirection.rs | ||
reduce.rs | ||
reject.rs | ||
rename.rs | ||
return_.rs | ||
reverse.rs | ||
rm.rs | ||
roll.rs | ||
rotate.rs | ||
run_external.rs | ||
save.rs | ||
select.rs | ||
semicolon.rs | ||
seq_char.rs | ||
seq_date.rs | ||
seq.rs | ||
sort_by.rs | ||
sort.rs | ||
source_env.rs | ||
split_by.rs | ||
split_column.rs | ||
split_row.rs | ||
table.rs | ||
tee.rs | ||
terminal.rs | ||
to_text.rs | ||
transpose.rs | ||
try_.rs | ||
ucp.rs | ||
ulimit.rs | ||
umkdir.rs | ||
uname.rs | ||
uniq_by.rs | ||
uniq.rs | ||
update.rs | ||
upsert.rs | ||
use_.rs | ||
utouch.rs | ||
where_.rs | ||
which.rs | ||
while_.rs | ||
window.rs | ||
with_env.rs | ||
wrap.rs | ||
zip.rs |