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Standardise the use of ShellError::UnsupportedInput and ShellError::TypeMismatch and add spans to every instance of the former (#7217)

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# 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.
This commit is contained in:
Leon
2022-12-23 16:48:53 +10:00
committed by GitHub
parent 9364bad625
commit dd7b7311b3
154 changed files with 1617 additions and 1025 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
crates/nu-command/src/strings/str_/substring.rs
View File

@ -136,7 +136,7 @@ fn action(input: &Value, args: &Arguments, head: Span) -> Value {
match start.cmp(&end) {
Ordering::Equal => Value::string("", head),
Ordering::Greater => Value::Error {
error: ShellError::UnsupportedInput(
error: ShellError::TypeMismatch(
"End must be greater than or equal to Start".to_string(),
head,
),
@ -165,13 +165,15 @@ fn action(input: &Value, args: &Arguments, head: Span) -> Value {
Value::string("", head)
}
}
// Propagate errors by explicitly matching them before the final case.
Value::Error { .. } => input.clone(),
other => Value::Error {
error: ShellError::UnsupportedInput(
format!(
"Input's type is {}. This command only works with strings.",
other.get_type()
),
"Only string values are supported".into(),
format!("input type: {:?}", other.get_type()),
head,
// This line requires the Value::Error match above.
other.expect_span(),
),
},
}
@ -186,7 +188,7 @@ fn process_arguments(range: &Value, head: Span) -> Result<(isize, isize), ShellE
}
Value::List { vals, .. } => {
if vals.len() > 2 {
Err(ShellError::UnsupportedInput(
Err(ShellError::TypeMismatch(
"More than two indices given".to_string(),
head,
))
@ -197,7 +199,7 @@ fn process_arguments(range: &Value, head: Span) -> Result<(isize, isize), ShellE
match v {
Value::Int { val, .. } => Ok(val.to_string()),
Value::String { val, .. } => Ok(val.to_string()),
_ => Err(ShellError::UnsupportedInput(
_ => Err(ShellError::TypeMismatch(
"could not perform substring. Expecting a string or int"
.to_string(),
head,
@ -210,19 +212,13 @@ fn process_arguments(range: &Value, head: Span) -> Result<(isize, isize), ShellE
let start = idx
.get(0)
.ok_or_else(|| {
ShellError::UnsupportedInput(
"could not perform substring".to_string(),
head,
)
ShellError::TypeMismatch("could not perform substring".to_string(), head)
})?
.to_string();
let end = idx
.get(1)
.ok_or_else(|| {
ShellError::UnsupportedInput(
"could not perform substring".to_string(),
head,
)
ShellError::TypeMismatch("could not perform substring".to_string(), head)
})?
.to_string();
Ok(SubstringText(start, end))
@ -234,19 +230,19 @@ fn process_arguments(range: &Value, head: Span) -> Result<(isize, isize), ShellE
let start = idx
.first()
.ok_or_else(|| {
ShellError::UnsupportedInput("could not perform substring".to_string(), head)
ShellError::TypeMismatch("could not perform substring".to_string(), head)
})?
.to_string();
let end = idx
.get(1)
.ok_or_else(|| {
ShellError::UnsupportedInput("could not perform substring".to_string(), head)
ShellError::TypeMismatch("could not perform substring".to_string(), head)
})?
.to_string();
Ok(SubstringText(start, end))
}
_ => Err(ShellError::UnsupportedInput(
_ => Err(ShellError::TypeMismatch(
"could not perform substring".to_string(),
head,
)),
@ -254,14 +250,14 @@ fn process_arguments(range: &Value, head: Span) -> Result<(isize, isize), ShellE
let start = match &search {
SubstringText(start, _) if start.is_empty() || start == "_" => 0,
SubstringText(start, _) => start.trim().parse().map_err(|_| {
ShellError::UnsupportedInput("could not perform substring".to_string(), head)
ShellError::TypeMismatch("could not perform substring".to_string(), head)
})?,
};
let end = match &search {
SubstringText(_, end) if end.is_empty() || end == "_" => isize::max_value(),
SubstringText(_, end) => end.trim().parse().map_err(|_| {
ShellError::UnsupportedInput("could not perform substring".to_string(), head)
ShellError::TypeMismatch("could not perform substring".to_string(), head)
})?,
};