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214714e0ab
<!-- 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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nu-cmd-extra
The commands in this crate are the extra commands of Nushell. These commands are not in a state to be guaranteed to be part of the 1.0 API; meaning that there is no guarantee longer term that these commands will be around into the future.
For a while we did exclude them behind the --features extra compile time
flag, meaning that the default release did not contain them. As we (the Nushell
team) shipped a full build including both extra and dataframe for some
time, we chose to sunset the extra feature but keep the commands in this
crate for now. In the future the commands may be moved to more topical crates
or discarded into plugins.