nushell/crates/nu-command/src/path/mod.rs
Leon dd7b7311b3
Standardise the use of ShellError::UnsupportedInput and ShellError::TypeMismatch and add spans to every instance of the former (#7217)
# Description

* I was dismayed to discover recently that UnsupportedInput and
TypeMismatch are used *extremely* inconsistently across the codebase.
UnsupportedInput is sometimes used for input type-checks (as per the
name!!), but *also* used for argument type-checks. TypeMismatch is also
used for both.
I thus devised the following standard: input type-checking *only* uses
UnsupportedInput, and argument type-checking *only* uses TypeMismatch.
Moreover, to differentiate them, UnsupportedInput now has *two* error
arrows (spans), one pointing at the command and the other at the input
origin, while TypeMismatch only has the one (because the command should
always be nearby)
* In order to apply that standard, a very large number of
UnsupportedInput uses were changed so that the input's span could be
retrieved and delivered to it.
* Additionally, I noticed many places where **errors are not propagated
correctly**: there are lots of `match` sites which take a Value::Error,
then throw it away and replace it with a new Value::Error with
less/misleading information (such as reporting the error as an
"incorrect type"). I believe that the earliest errors are the most
important, and should always be propagated where possible.
* Also, to standardise one broad subset of UnsupportedInput error
messages, who all used slightly different wordings of "expected
`<type>`, got `<type>`", I created OnlySupportsThisInputType as a
variant of it.
* Finally, a bunch of error sites that had "repeated spans" - i.e. where
an error expected two spans, but `call.head` was given for both - were
fixed to use different spans.

# Example
BEFORE
```
〉20b | str starts-with 'a'
Error: nu:🐚:unsupported_input (link)

  × Unsupported input
   ╭─[entry #31:1:1]
 1 │ 20b | str starts-with 'a'
   ·   ┬
   ·   ╰── Input's type is filesize. This command only works with strings.
   ╰────

〉'a' | math cos
Error: nu:🐚:unsupported_input (link)

  × Unsupported input
   ╭─[entry #33:1:1]
 1 │ 'a' | math cos
   · ─┬─
   ·  ╰── Only numerical values are supported, input type: String
   ╰────

〉0x[12] | encode utf8
Error: nu:🐚:unsupported_input (link)

  × Unsupported input
   ╭─[entry #38:1:1]
 1 │ 0x[12] | encode utf8
   ·          ───┬──
   ·             ╰── non-string input
   ╰────
```
AFTER
```
〉20b | str starts-with 'a'
Error: nu:🐚:pipeline_mismatch (link)

  × Pipeline mismatch.
   ╭─[entry #1:1:1]
 1 │ 20b | str starts-with 'a'
   ·   ┬   ───────┬───────
   ·   │          ╰── only string input data is supported
   ·   ╰── input type: filesize
   ╰────

〉'a' | math cos
Error: nu:🐚:pipeline_mismatch (link)

  × Pipeline mismatch.
   ╭─[entry #2:1:1]
 1 │ 'a' | math cos
   · ─┬─   ────┬───
   ·  │        ╰── only numeric input data is supported
   ·  ╰── input type: string
   ╰────

〉0x[12] | encode utf8
Error: nu:🐚:pipeline_mismatch (link)

  × Pipeline mismatch.
   ╭─[entry #3:1:1]
 1 │ 0x[12] | encode utf8
   · ───┬──   ───┬──
   ·    │        ╰── only string input data is supported
   ·    ╰── input type: binary
   ╰────
```

# User-Facing Changes

Various error messages suddenly make more sense (i.e. have two arrows
instead of one).

# 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` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# 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.
2022-12-23 01:48:53 -05:00

109 lines
3.1 KiB
Rust

mod basename;
mod dirname;
mod exists;
mod expand;
mod join;
mod parse;
pub mod path_;
mod relative_to;
mod split;
mod r#type;
use std::path::Path as StdPath;
pub use basename::SubCommand as PathBasename;
pub use dirname::SubCommand as PathDirname;
pub use exists::SubCommand as PathExists;
pub use expand::SubCommand as PathExpand;
pub use join::SubCommand as PathJoin;
pub use parse::SubCommand as PathParse;
pub use path_::PathCommand as Path;
pub use r#type::SubCommand as PathType;
pub use relative_to::SubCommand as PathRelativeTo;
pub use split::SubCommand as PathSplit;
use nu_protocol::{ShellError, Span, Value};
#[cfg(windows)]
const ALLOWED_COLUMNS: [&str; 4] = ["prefix", "parent", "stem", "extension"];
#[cfg(not(windows))]
const ALLOWED_COLUMNS: [&str; 3] = ["parent", "stem", "extension"];
trait PathSubcommandArguments {
fn get_columns(&self) -> Option<Vec<String>>;
}
fn operate<F, A>(cmd: &F, args: &A, v: Value, name: Span) -> Value
where
F: Fn(&StdPath, Span, &A) -> Value + Send + Sync + 'static,
A: PathSubcommandArguments + Send + Sync + 'static,
{
match v {
Value::String { val, span } => cmd(StdPath::new(&val), span, args),
Value::Record { cols, vals, span } => {
let col = if let Some(col) = args.get_columns() {
col
} else {
vec![]
};
if col.is_empty() {
return Value::Error {
error: ShellError::UnsupportedInput(
String::from("when the input is a table, you must specify the columns"),
"value originates from here".into(),
name,
span,
),
};
}
let mut output_cols = vec![];
let mut output_vals = vec![];
for (k, v) in cols.iter().zip(vals) {
output_cols.push(k.clone());
if col.contains(k) {
let new_val = match v {
Value::String { val, span } => cmd(StdPath::new(&val), span, args),
_ => return handle_invalid_values(v, name),
};
output_vals.push(new_val);
} else {
output_vals.push(v);
}
}
Value::Record {
cols: output_cols,
vals: output_vals,
span,
}
}
_ => handle_invalid_values(v, name),
}
}
fn handle_invalid_values(rest: Value, name: Span) -> Value {
Value::Error {
error: err_from_value(&rest, name),
}
}
fn err_from_value(rest: &Value, name: Span) -> ShellError {
match rest.span() {
Ok(span) => {
if rest.is_nothing() {
ShellError::OnlySupportsThisInputType(
"string, record or list".into(),
"nothing".into(),
name,
span,
)
} else {
ShellError::PipelineMismatch("string, row or list".into(), name, span)
}
}
Err(error) => error,
}
}