berkus
/
miette
mirror of https://github.com/zkat/miette.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

README now generaed from lib.rs via `cargo readme`.

This commit is contained in:
Moritz Moeller 2022-02-25 02:16:45 +01:00
parent bcebd54456
commit 1166dd0e87
4 changed files with 678 additions and 108 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

238
README.md
View File

@ -1,12 +1,15 @@
you run miette? You run her code like the software? Oh. Oh! Error code for
# `miette`
You run miette? You run her code like the software? Oh. Oh! Error code for
coder! Error code for One Thousand Lines! coder! Error code for One Thousand Lines!
## About ### About
`miette` is a diagnostic library for Rust. It includes a series of `miette` is a diagnostic library for Rust. It includes a series of
traits/protocols that allow you to hook into its error reporting facilities, traits/protocols that allow you to hook into its error reporting facilities,
and even write your own error reports! It lets you define error types that can and even write your own error reports! It lets you define error types that
print out like this (or in any format you like!): can print out like this (or in any format you like!):
<img src="https://raw.githubusercontent.com/zkat/miette/main/images/serde_json.png" alt="Hi! miette also includes a screen-reader-oriented diagnostic printer that's enabled in various situations, such as when you use NO_COLOR or CLICOLOR settings, or on CI. This behavior is also fully configurable and customizable. For example, this is what this particular diagnostic will look like when the narrated printer is enabled: <img src="https://raw.githubusercontent.com/zkat/miette/main/images/serde_json.png" alt="Hi! miette also includes a screen-reader-oriented diagnostic printer that's enabled in various situations, such as when you use NO_COLOR or CLICOLOR settings, or on CI. This behavior is also fully configurable and customizable. For example, this is what this particular diagnostic will look like when the narrated printer is enabled:
\ \
@ -19,17 +22,17 @@ at line 1, column 1659
snippet line 1: gs&quot;:[&quot;json&quot;],&quot;title&quot;:&quot;&quot;,&quot;version&quot;:&quot;1.0.0&quot;},&quot;packageContent&quot;:&quot;https://api.nuget.o snippet line 1: gs&quot;:[&quot;json&quot;],&quot;title&quot;:&quot;&quot;,&quot;version&quot;:&quot;1.0.0&quot;},&quot;packageContent&quot;:&quot;https://api.nuget.o
highlight starting at line 1, column 1699: last parsing location highlight starting at line 1, column 1699: last parsing location
\ \
diagnostic help: This is a bug. It might be in ruget, or it might be in the source you're using, diagnostic help: This is a bug. It might be in ruget, or it might be in the
but it's definitely a bug and should be reported. source you're using, but it's definitely a bug and should be reported.
diagnostic error code: ruget::api::bad_json diagnostic error code: ruget::api::bad_json
" /> " />
> **NOTE: You must enable the `"fancy"` crate feature to get fancy report > **NOTE: You must enable the `"fancy"` crate feature to get fancy report
output like in the screenshots above.** You should only do this in your toplevel output like in the screenshots above.** You should only do this in your
crate, as the fancy feature pulls in a number of dependencies that libraries toplevel crate, as the fancy feature pulls in a number of dependencies that
and such might not want. libraries and such might not want.
## Table of Contents <!-- omit in toc --> ### Table of Contents <!-- omit in toc -->
- [About](#about) - [About](#about)
- [Features](#features) - [Features](#features)
@ -47,30 +50,32 @@ and such might not want.
- [Acknowledgements](#acknowledgements) - [Acknowledgements](#acknowledgements)
- [License](#license) - [License](#license)
## Features ### Features
- Generic [`Diagnostic`] protocol, compatible (and dependent on) `std::error::Error`. - Generic [`Diagnostic`] protocol, compatible (and dependent on)
[`std::error::Error`].
- Unique error codes on every [`Diagnostic`]. - Unique error codes on every [`Diagnostic`].
- Custom links to get more details on error codes. - Custom links to get more details on error codes.
- Super handy derive macro for defining diagnostic metadata. - Super handy derive macro for defining diagnostic metadata.
- Replacements for [`anyhow`](https://docs.rs/anyhow)/[`eyre`](https://docs.rs/eyre) - Replacements for [`anyhow`](https://docs.rs/anyhow)/[`eyre`](https://docs.rs/eyre)
types [`Result`], [`Report`] and the [`miette!`] macro for the `anyhow!`/`eyre!` types [`Result`], [`Report`] and the [`miette!`] macro for the
macros. `anyhow!`/`eyre!` macros.
- Generic support for arbitrary [`SourceCode`]s for snippet data, with default - Generic support for arbitrary [`SourceCode`]s for snippet data, with
support for `String`s included. default support for `String`s included.
The `miette` crate also comes bundled with a default [`ReportHandler`] with the following features: The `miette` crate also comes bundled with a default [`ReportHandler`] with
the following features:
- Fancy graphical [diagnostic output](#about), using ANSI/Unicode text - Fancy graphical [diagnostic output](#about), using ANSI/Unicode text
- single- and multi-line highlighting support - single- and multi-line highlighting support
- Screen reader/braille support, gated on [`NO_COLOR`](http://no-color.org/), - Screen reader/braille support, gated on [`NO_COLOR`](http://no-color.org/),
and other heuristics. and other heuristics.
- Fully customizable graphical theming (or overriding the printers entirely). - Fully customizable graphical theming (or overriding the printers
entirely).
- Cause chain printing - Cause chain printing
- Turns diagnostic codes into links in [supported - Turns diagnostic codes into links in [supported terminals](https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda).
terminals](https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda).
## Installing ### Installing
Using [`cargo-edit`](https://crates.io/crates/cargo-edit): Using [`cargo-edit`](https://crates.io/crates/cargo-edit):
@ -84,7 +89,7 @@ If you want to use the fancy printer in all these screenshots:
$ cargo add miette --features fancy $ cargo add miette --features fancy
``` ```
## Example ### Example
```rust ```rust
/* /*
@ -100,7 +105,7 @@ use thiserror::Error;
#[diagnostic( #[diagnostic(
code(oops::my::bad), code(oops::my::bad),
url(docsrs), url(docsrs),
help("try doing it better next time?"), help("try doing it better next time?")
)] )]
struct MyBad { struct MyBad {
// The Source that we're gonna be printing snippets out of. // The Source that we're gonna be printing snippets out of.
@ -119,7 +124,7 @@ Use this `Result` type (or its expanded version) as the return type
throughout your app (but NOT your libraries! Those should always return throughout your app (but NOT your libraries! Those should always return
concrete types!). concrete types!).
*/ */
use miette::{Result, NamedSource}; use miette::{NamedSource, Result};
fn this_fails() -> Result<()> { fn this_fails() -> Result<()> {
// You can use plain strings as a `Source`, or anything that implements // You can use plain strings as a `Source`, or anything that implements
// the one-method `Source` trait. // the one-method `Source` trait.
@ -166,9 +171,9 @@ diagnostic help: Change int or string to be the right types and try again.
diagnostic code: nu::parser::unsupported_operation diagnostic code: nu::parser::unsupported_operation
For more details, see https://docs.rs/nu-parser/0.1.0/nu-parser/enum.ParseError.html#variant.UnsupportedOperation"> For more details, see https://docs.rs/nu-parser/0.1.0/nu-parser/enum.ParseError.html#variant.UnsupportedOperation">
## Using ### Using
### ... in libraries #### ... in libraries
`miette` is _fully compatible_ with library usage. Consumers who don't know `miette` is _fully compatible_ with library usage. Consumers who don't know
about, or don't want, `miette` features can safely use its error types as about, or don't want, `miette` features can safely use its error types as
@ -177,14 +182,14 @@ regular [`std::error::Error`].
We highly recommend using something like [`thiserror`](https://docs.rs/thiserror) We highly recommend using something like [`thiserror`](https://docs.rs/thiserror)
to define unique error types and error wrappers for your library. to define unique error types and error wrappers for your library.
While `miette` integrates smoothly with `thiserror`, it is _not required_. If While `miette` integrates smoothly with `thiserror`, it is _not required_.
you don't want to use the [`Diagnostic`] derive macro, you can implement the If you don't want to use the [`Diagnostic`] derive macro, you can implement
trait directly, just like with `std::error::Error`. the trait directly, just like with `std::error::Error`.
```rust ```rust
// lib/error.rs // lib/error.rs
use thiserror::Error;
use miette::Diagnostic; use miette::Diagnostic;
use thiserror::Error;
#[derive(Error, Diagnostic, Debug)] #[derive(Error, Diagnostic, Debug)]
pub enum MyLibError { pub enum MyLibError {
@ -202,19 +207,19 @@ Then, return this error type from all your fallible public APIs. It's a best
practice to wrap any "external" error types in your error `enum` instead of practice to wrap any "external" error types in your error `enum` instead of
using something like [`Report`] in a library. using something like [`Report`] in a library.
### ... in application code #### ... in application code
Application code tends to work a little differently than libraries. You don't Application code tends to work a little differently than libraries. You
always need or care to define dedicated error wrappers for errors coming from don't always need or care to define dedicated error wrappers for errors
external libraries and tools. coming from external libraries and tools.
For this situation, `miette` includes two tools: [`Report`] and For this situation, `miette` includes two tools: [`Report`] and
[`IntoDiagnostic`]. They work in tandem to make it easy to convert regular [`IntoDiagnostic`]. They work in tandem to make it easy to convert regular
`std::error::Error`s into [`Diagnostic`]s. Additionally, there's a `std::error::Error`s into [`Diagnostic`]s. Additionally, there's a
[`Result`] type alias that you can use to be more terse. [`Result`] type alias that you can use to be more terse.
When dealing with non-`Diagnostic` types, you'll want to `.into_diagnostic()` When dealing with non-`Diagnostic` types, you'll want to
them: `.into_diagnostic()` them:
```rust ```rust
// my_app/lib/my_internal_file.rs // my_app/lib/my_internal_file.rs
@ -226,9 +231,10 @@ pub fn some_tool() -> Result<Version> {
} }
``` ```
`miette` also includes an `anyhow`/`eyre`-style `Context`/`WrapErr` traits that `miette` also includes an `anyhow`/`eyre`-style `Context`/`WrapErr` traits
you can import to add ad-hoc context messages to your `Diagnostic`s, as well, that you can import to add ad-hoc context messages to your `Diagnostic`s, as
though you'll still need to use `.into_diagnostic()` to make use of it: well, though you'll still need to use `.into_diagnostic()` to make use of
it:
```rust ```rust
// my_app/lib/my_internal_file.rs // my_app/lib/my_internal_file.rs
@ -236,23 +242,26 @@ use miette::{IntoDiagnostic, Result, WrapErr};
use semver::Version; use semver::Version;
pub fn some_tool() -> Result<Version> { pub fn some_tool() -> Result<Version> {
Ok("1.2.x".parse().into_diagnostic().wrap_err("Parsing this tool's semver version failed.")?) Ok("1.2.x"
.parse()
.into_diagnostic()
.wrap_err("Parsing this tool's semver version failed.")?)
} }
``` ```
### ... in `main()` #### ... in `main()`
`main()` is just like any other part of your application-internal code. Use `main()` is just like any other part of your application-internal code. Use
`Result` as your return value, and it will pretty-print your diagnostics `Result` as your return value, and it will pretty-print your diagnostics
automatically. automatically.
> **NOTE:** You must enable the `"fancy"` crate feature to get fancy report > **NOTE:** You must enable the `"fancy"` crate feature to get fancy report
output like in the screenshots here.** You should only do this in your toplevel output like in the screenshots here.** You should only do this in your
crate, as the fancy feature pulls in a number of dependencies that libraries toplevel crate, as the fancy feature pulls in a number of dependencies that
and such might not want. libraries and such might not want.
```rust ```rust
use miette::{Result, IntoDiagnostic}; use miette::{IntoDiagnostic, Result};
use semver::Version; use semver::Version;
fn pretend_this_is_main() -> Result<()> { fn pretend_this_is_main() -> Result<()> {
@ -270,23 +279,24 @@ enabled:
miette = { version = "X.Y.Z", features = ["fancy"] } miette = { version = "X.Y.Z", features = ["fancy"] }
``` ```
### ... diagnostic code URLs #### ... diagnostic code URLs
`miette` supports providing a URL for individual diagnostics. This URL will be `miette` supports providing a URL for individual diagnostics. This URL will
displayed as an actual link in supported terminals, like so: be displayed as an actual link in supported terminals, like so:
<img <img
src="https://raw.githubusercontent.com/zkat/miette/main/images/code_linking.png" src="https://raw.githubusercontent.com/zkat/miette/main/images/code_linking.png"
alt=" Example showing the graphical report printer for miette pretty-printing alt=" Example showing the graphical report printer for miette
an error code. The code is underlined and followed by text saying to 'click pretty-printing an error code. The code is underlined and followed by text
here'. A hover tooltip shows a full-fledged URL that can be Ctrl+Clicked to saying to 'click here'. A hover tooltip shows a full-fledged URL that can be
open in a browser. Ctrl+Clicked to open in a browser.
\ \
This feature is also available in the narratable printer. It will add a line This feature is also available in the narratable printer. It will add a line
after printing the error code showing a plain URL that you can visit. after printing the error code showing a plain URL that you can visit.
"> ">
To use this, you can add a `url()` sub-param to your `#[diagnostic]` attribute: To use this, you can add a `url()` sub-param to your `#[diagnostic]`
attribute:
```rust ```rust
use miette::Diagnostic; use miette::Diagnostic;
@ -303,10 +313,10 @@ struct MyErr;
``` ```
Additionally, if you're developing a library and your error type is exported Additionally, if you're developing a library and your error type is exported
from your crate's top level, you can use a special `url(docsrs)` option instead from your crate's top level, you can use a special `url(docsrs)` option
of manually constructing the URL. This will automatically create a link to this instead of manually constructing the URL. This will automatically create a
diagnostic on `docs.rs`, so folks can just go straight to your (very high link to this diagnostic on `docs.rs`, so folks can just go straight to your
quality and detailed!) documentation on this diagnostic: (very high quality and detailed!) documentation on this diagnostic:
```rust ```rust
use miette::Diagnostic; use miette::Diagnostic;
@ -322,21 +332,21 @@ use thiserror::Error;
struct MyErr; struct MyErr;
``` ```
### ... snippets #### ... snippets
Along with its general error handling and reporting features, `miette` also Along with its general error handling and reporting features, `miette` also
includes facilities for adding error spans/annotations/labels to your output. includes facilities for adding error spans/annotations/labels to your
This can be very useful when an error is syntax-related, but you can even use output. This can be very useful when an error is syntax-related, but you can
it to print out sections of your own source code! even use it to print out sections of your own source code!
To achieve this, `miette` defines its own lightweight [`SourceSpan`] type. This To achieve this, `miette` defines its own lightweight [`SourceSpan`] type.
is a basic byte-offset and length into an associated [`SourceCode`] and, along This is a basic byte-offset and length into an associated [`SourceCode`]
with the latter, gives `miette` all the information it needs to pretty-print and, along with the latter, gives `miette` all the information it needs to
some snippets! You can also use your own `Into<SourceSpan>` types as label pretty-print some snippets! You can also use your own `Into<SourceSpan>`
spans. types as label spans.
The easiest way to define errors like this is to use the `derive(Diagnostic)` The easiest way to define errors like this is to use the
macro: `derive(Diagnostic)` macro:
```rust ```rust
use miette::{Diagnostic, SourceSpan}; use miette::{Diagnostic, SourceSpan};
@ -362,13 +372,13 @@ pub struct MyErrorType {
} }
``` ```
### ... multiple related errors #### ... multiple related errors
`miette` supports collecting multiple errors into a single diagnostic, and `miette` supports collecting multiple errors into a single diagnostic, and
printing them all together nicely. printing them all together nicely.
To do so, use the `#[related]` tag on any `IntoIter` field in your `Diagnostic` To do so, use the `#[related]` tag on any `IntoIter` field in your
type: `Diagnostic` type:
```rust ```rust
use miette::Diagnostic; use miette::Diagnostic;
@ -382,13 +392,13 @@ struct MyError {
} }
``` ```
### ... delayed source code #### ... delayed source code
Sometimes it makes sense to add source code to the error message later. One Sometimes it makes sense to add source code to the error message later. One
option is to use [`with_source_code()`](Report::with_source_code) method for option is to use [`with_source_code()`](Report::with_source_code) method for
that: that:
```rust,no_run ```rust
use miette::{Diagnostic, SourceSpan}; use miette::{Diagnostic, SourceSpan};
use thiserror::Error; use thiserror::Error;
@ -403,7 +413,9 @@ pub struct MyErrorType {
fn do_something() -> miette::Result<()> { fn do_something() -> miette::Result<()> {
// This function emits actual error with label // This function emits actual error with label
return Err(MyErrorType { err_span: (7..11).into() })?; return Err(MyErrorType {
err_span: (7..11).into(),
})?;
} }
fn main() -> miette::Result<()> { fn main() -> miette::Result<()> {
@ -412,15 +424,14 @@ fn main() -> miette::Result<()> {
error.with_source_code(String::from("source code")) error.with_source_code(String::from("source code"))
}) })
} }
``` ```
Also source code can be provided by a wrapper type. This is especially useful Also source code can be provided by a wrapper type. This is especially
in combination with `related`, when multiple errors should be emitted at the useful in combination with `related`, when multiple errors should be emitted
same time: at the same time:
```rust,no_run ```rust
use miette::{Report, Diagnostic, SourceSpan}; use miette::{Diagnostic, Report, SourceSpan};
use thiserror::Error; use thiserror::Error;
#[derive(Diagnostic, Debug, Error)] #[derive(Diagnostic, Debug, Error)]
@ -446,56 +457,59 @@ pub struct MultiError {
fn do_something() -> Result<(), Vec<InnerError>> { fn do_something() -> Result<(), Vec<InnerError>> {
Err(vec![ Err(vec![
InnerError { err_span: (0..6).into() }, InnerError {
InnerError { err_span: (7..11).into() }, err_span: (0..6).into(),
},
InnerError {
err_span: (7..11).into(),
},
]) ])
} }
fn main() -> miette::Result<()> { fn main() -> miette::Result<()> {
do_something().map_err(|err_list| { do_something().map_err(|err_list| MultiError {
MultiError { source_code: "source code".into(),
source_code: "source code".into(), related: err_list,
related: err_list,
}
})?; })?;
Ok(()) Ok(())
} }
``` ```
### ... handler options #### ... handler options
[`MietteHandler`] is the default handler, and is very customizable. In most [`MietteHandler`] is the default handler, and is very customizable. In most
cases, you can simply use [`MietteHandlerOpts`] to tweak its behavior instead cases, you can simply use [`MietteHandlerOpts`] to tweak its behavior
of falling back to your own custom handler. instead of falling back to your own custom handler.
Usage is like so: Usage is like so:
```rust ```rust
miette::set_hook(Box::new(|_| { miette::set_hook(Box::new(|_| {
Box::new(miette::MietteHandlerOpts::new() Box::new(
.terminal_links(true) miette::MietteHandlerOpts::new()
.unicode(false) .terminal_links(true)
.context_lines(3) .unicode(false)
.tab_width(4) .context_lines(3)
.build()) .tab_width(4)
.build(),
)
})) }))
# .unwrap()
``` ```
See the docs for [`MietteHandlerOpts`] for more details on what you can See the docs for [`MietteHandlerOpts`] for more details on what you can
customize! customize!
## Acknowledgements ### Acknowledgements
`miette` was not developed in a void. It owes enormous credit to various other `miette` was not developed in a void. It owes enormous credit to various
projects and their authors: other projects and their authors:
- [`anyhow`](http://crates.io/crates/anyhow) and - [`anyhow`](http://crates.io/crates/anyhow) and [`color-eyre`](https://crates.io/crates/color-eyre):
[`color-eyre`](https://crates.io/crates/color-eyre): these two enormously these two enormously influential error handling libraries have pushed
influential error handling libraries have pushed forward the experience of forward the experience of application-level error handling and error
application-level error handling and error reporting. `miette`'s `Report` reporting. `miette`'s `Report` type is an attempt at a very very rough
type is an attempt at a very very rough version of their `Report` types. version of their `Report` types.
- [`thiserror`](https://crates.io/crates/thiserror) for setting the standard - [`thiserror`](https://crates.io/crates/thiserror) for setting the standard
for library-level error definitions, and for being the inspiration behind for library-level error definitions, and for being the inspiration behind
`miette`'s derive macro. `miette`'s derive macro.
@ -504,7 +518,7 @@ projects and their authors:
- [`ariadne`](https://crates.io/crates/ariadne) for pushing forward how - [`ariadne`](https://crates.io/crates/ariadne) for pushing forward how
_pretty_ these diagnostics can really look! _pretty_ these diagnostics can really look!
## License ### License
`miette` is released to the Rust community under the `miette` is released to the Rust community under the
[Apache license 2.0](./LICENSE). [Apache license 2.0](./LICENSE).
@ -513,3 +527,15 @@ It also includes code taken from [`eyre`](https://github.com/yaahc/eyre),
and some from [`thiserror`](https://github.com/dtolnay/thiserror), also under and some from [`thiserror`](https://github.com/dtolnay/thiserror), also under
the Apache License. Some code is taken from the Apache License. Some code is taken from
[`ariadne`](https://github.com/zesterer/ariadne), which is MIT licensed. [`ariadne`](https://github.com/zesterer/ariadne), which is MIT licensed.
[`miette!`]: https://docs.rs/miette/latest/miette/macro.miette.html
[`std::error::Error`]: https://doc.rust-lang.org/nightly/std/error/trait.Error.html
[`Diagnostic`]: https://docs.rs/miette/latest/miette/struct.Diagnostic.html
[`IntoDiagnostic`]: https://docs.rs/miette/latest/miette/trait.IntoDiagnostic.html
[`MietteHandlerOpts`]: https://docs.rs/miette/latest/miette/struct.MietteHandlerOpts.html
[`MietteHandler`]: https://docs.rs/miette/latest/miette/struct.MietteHandler.html
[`Report`]: https://docs.rs/miette/latest/miette/struct.Report.html
[`ReportHandler`]: https://docs.rs/miette/latest/miette/struct.ReportHandler.html
[`Result`]: https://docs.rs/miette/latest/miette/type.Result.html
[`SourceCode`]: https://docs.rs/miette/latest/miette/struct.SourceCode.html
[`SourceSpan`]: https://docs.rs/miette/latest/miette/struct.SourceSpan.html

16
README.tpl Normal file
View File

@ -0,0 +1,16 @@
# `{{crate}}`
{{readme}}
[`miette!`]: https://docs.rs/miette/latest/miette/macro.miette.html
[`std::error::Error`]: https://doc.rust-lang.org/nightly/std/error/trait.Error.html
[`Diagnostic`]: https://docs.rs/miette/latest/miette/struct.Diagnostic.html
[`IntoDiagnostic`]: https://docs.rs/miette/latest/miette/trait.IntoDiagnostic.html
[`MietteHandlerOpts`]: https://docs.rs/miette/latest/miette/struct.MietteHandlerOpts.html
[`MietteHandler`]: https://docs.rs/miette/latest/miette/struct.MietteHandler.html
[`Report`]: https://docs.rs/miette/latest/miette/struct.Report.html
[`ReportHandler`]: https://docs.rs/miette/latest/miette/struct.ReportHandler.html
[`Result`]: https://docs.rs/miette/latest/miette/type.Result.html
[`SourceCode`]: https://docs.rs/miette/latest/miette/struct.SourceCode.html
[`SourceSpan`]: https://docs.rs/miette/latest/miette/struct.SourceSpan.html

3
rustfmt.toml Normal file
View File

@ -0,0 +1,3 @@
edition = "2021"
wrap_comments = true
format_code_in_doc_comments = true

529
src/lib.rs
View File

@ -1,7 +1,532 @@
#![doc = include_str!("../README.md")]
#![deny(missing_docs, missing_debug_implementations, nonstandard_style)] #![deny(missing_docs, missing_debug_implementations, nonstandard_style)]
#![warn(unreachable_pub, rust_2018_idioms)] #![warn(unreachable_pub, rust_2018_idioms)]
//! You run miette? You run her code like the software? Oh. Oh! Error code for
//! coder! Error code for One Thousand Lines!
//!
//! ## About
//!
//! `miette` is a diagnostic library for Rust. It includes a series of
//! traits/protocols that allow you to hook into its error reporting facilities,
//! and even write your own error reports! It lets you define error types that
//! can print out like this (or in any format you like!):
//!
//! <img src="https://raw.githubusercontent.com/zkat/miette/main/images/serde_json.png" alt="Hi! miette also includes a screen-reader-oriented diagnostic printer that's enabled in various situations, such as when you use NO_COLOR or CLICOLOR settings, or on CI. This behavior is also fully configurable and customizable. For example, this is what this particular diagnostic will look like when the narrated printer is enabled:
//! \
//! Error: Received some bad JSON from the source. Unable to parse.
//! Caused by: missing field `foo` at line 1 column 1700
//! \
//! Begin snippet for https://api.nuget.org/v3/registration5-gz-semver2/json.net/index.json starting
//! at line 1, column 1659
//! \
//! snippet line 1: gs&quot;:[&quot;json&quot;],&quot;title&quot;:&quot;&quot;,&quot;version&quot;:&quot;1.0.0&quot;},&quot;packageContent&quot;:&quot;https://api.nuget.o
//! highlight starting at line 1, column 1699: last parsing location
//! \
//! diagnostic help: This is a bug. It might be in ruget, or it might be in the
//! source you're using, but it's definitely a bug and should be reported.
//! diagnostic error code: ruget::api::bad_json
//! " />
//!
//! > **NOTE: You must enable the `"fancy"` crate feature to get fancy report
//! output like in the screenshots above.** You should only do this in your
//! toplevel crate, as the fancy feature pulls in a number of dependencies that
//! libraries and such might not want.
//!
//! ## Table of Contents <!-- omit in toc -->
//!
//! - [About](#about)
//! - [Features](#features)
//! - [Installing](#installing)
//! - [Example](#example)
//! - [Using](#using)
//! - [... in libraries](#-in-libraries)
//! - [... in application code](#-in-application-code)
//! - [... in `main()`](#-in-main)
//! - [... diagnostic code URLs](#-diagnostic-code-urls)
//! - [... snippets](#-snippets)
//! - [... multiple related errors](#-multiple-related-errors)
//! - [... delayed source code](#-delayed-source-code)
//! - [... handler options](#-handler-options)
//! - [Acknowledgements](#acknowledgements)
//! - [License](#license)
//!
//! ## Features
//!
//! - Generic [`Diagnostic`] protocol, compatible (and dependent on)
//! [`std::error::Error`].
//! - Unique error codes on every [`Diagnostic`].
//! - Custom links to get more details on error codes.
//! - Super handy derive macro for defining diagnostic metadata.
//! - Replacements for [`anyhow`](https://docs.rs/anyhow)/[`eyre`](https://docs.rs/eyre)
//! types [`Result`], [`Report`] and the [`miette!`] macro for the
//! `anyhow!`/`eyre!` macros.
//! - Generic support for arbitrary [`SourceCode`]s for snippet data, with
//! default support for `String`s included.
//!
//! The `miette` crate also comes bundled with a default [`ReportHandler`] with
//! the following features:
//!
//! - Fancy graphical [diagnostic output](#about), using ANSI/Unicode text
//! - single- and multi-line highlighting support
//! - Screen reader/braille support, gated on [`NO_COLOR`](http://no-color.org/),
//! and other heuristics.
//! - Fully customizable graphical theming (or overriding the printers
//! entirely).
//! - Cause chain printing
//! - Turns diagnostic codes into links in [supported terminals](https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda).
//!
//! ## Installing
//!
//! Using [`cargo-edit`](https://crates.io/crates/cargo-edit):
//!
//! ```sh
//! $ cargo add miette
//! ```
//!
//! If you want to use the fancy printer in all these screenshots:
//!
//! ```sh
//! $ cargo add miette --features fancy
//! ```
//!
//! ## Example
//!
//! ```rust
//! /*
//! You can derive a `Diagnostic` from any `std::error::Error` type.
//!
//! `thiserror` is a great way to define them, and plays nicely with `miette`!
//! */
//! use miette::{Diagnostic, SourceSpan};
//! use thiserror::Error;
//!
//! #[derive(Error, Debug, Diagnostic)]
//! #[error("oops!")]
//! #[diagnostic(
//! code(oops::my::bad),
//! url(docsrs),
//! help("try doing it better next time?")
//! )]
//! struct MyBad {
//! // The Source that we're gonna be printing snippets out of.
//! // This can be a String if you don't have or care about file names.
//! #[source_code]
//! src: NamedSource,
//! // Snippets and highlights can be included in the diagnostic!
//! #[label("This bit here")]
//! bad_bit: SourceSpan,
//! }
//!
//! /*
//! Now let's define a function!
//!
//! Use this `Result` type (or its expanded version) as the return type
//! throughout your app (but NOT your libraries! Those should always return
//! concrete types!).
//! */
//! use miette::{NamedSource, Result};
//! fn this_fails() -> Result<()> {
//! // You can use plain strings as a `Source`, or anything that implements
//! // the one-method `Source` trait.
//! let src = "source\n text\n here".to_string();
//! let len = src.len();
//!
//! Err(MyBad {
//! src: NamedSource::new("bad_file.rs", src),
//! bad_bit: (9, 4).into(),
//! })?;
//!
//! Ok(())
//! }
//!
//! /*
//! Now to get everything printed nicely, just return a `Result<()>`
//! and you're all set!
//!
//! Note: You can swap out the default reporter for a custom one using
//! `miette::set_hook()`
//! */
//! fn pretend_this_is_main() -> Result<()> {
//! // kaboom~
//! this_fails()?;
//!
//! Ok(())
//! }
//! ```
//!
//! And this is the output you'll get if you run this program:
//!
//! <img src="https://raw.githubusercontent.com/zkat/miette/main/images/single-line-example.png" alt="
//! Narratable printout:
//! \
//! Error: Types mismatched for operation.
//! Diagnostic severity: error
//! Begin snippet starting at line 1, column 1
//! \
//! snippet line 1: 3 + &quot;5&quot;
//! label starting at line 1, column 1: int
//! label starting at line 1, column 1: doesn't support these values.
//! label starting at line 1, column 1: string
//! diagnostic help: Change int or string to be the right types and try again.
//! diagnostic code: nu::parser::unsupported_operation
//! For more details, see https://docs.rs/nu-parser/0.1.0/nu-parser/enum.ParseError.html#variant.UnsupportedOperation">
//!
//! ## Using
//!
//! ### ... in libraries
//!
//! `miette` is _fully compatible_ with library usage. Consumers who don't know
//! about, or don't want, `miette` features can safely use its error types as
//! regular [`std::error::Error`].
//!
//! We highly recommend using something like [`thiserror`](https://docs.rs/thiserror)
//! to define unique error types and error wrappers for your library.
//!
//! While `miette` integrates smoothly with `thiserror`, it is _not required_.
//! If you don't want to use the [`Diagnostic`] derive macro, you can implement
//! the trait directly, just like with `std::error::Error`.
//!
//! ```rust
//! // lib/error.rs
//! use miette::Diagnostic;
//! use thiserror::Error;
//!
//! #[derive(Error, Diagnostic, Debug)]
//! pub enum MyLibError {
//! #[error(transparent)]
//! #[diagnostic(code(my_lib::io_error))]
//! IoError(#[from] std::io::Error),
//!
//! #[error("Oops it blew up")]
//! #[diagnostic(code(my_lib::bad_code))]
//! BadThingHappened,
//! }
//! ```
//!
//! Then, return this error type from all your fallible public APIs. It's a best
//! practice to wrap any "external" error types in your error `enum` instead of
//! using something like [`Report`] in a library.
//!
//! ### ... in application code
//!
//! Application code tends to work a little differently than libraries. You
//! don't always need or care to define dedicated error wrappers for errors
//! coming from external libraries and tools.
//!
//! For this situation, `miette` includes two tools: [`Report`] and
//! [`IntoDiagnostic`]. They work in tandem to make it easy to convert regular
//! `std::error::Error`s into [`Diagnostic`]s. Additionally, there's a
//! [`Result`] type alias that you can use to be more terse.
//!
//! When dealing with non-`Diagnostic` types, you'll want to
//! `.into_diagnostic()` them:
//!
//! ```rust
//! // my_app/lib/my_internal_file.rs
//! use miette::{IntoDiagnostic, Result};
//! use semver::Version;
//!
//! pub fn some_tool() -> Result<Version> {
//! Ok("1.2.x".parse().into_diagnostic()?)
//! }
//! ```
//!
//! `miette` also includes an `anyhow`/`eyre`-style `Context`/`WrapErr` traits
//! that you can import to add ad-hoc context messages to your `Diagnostic`s, as
//! well, though you'll still need to use `.into_diagnostic()` to make use of
//! it:
//!
//! ```rust
//! // my_app/lib/my_internal_file.rs
//! use miette::{IntoDiagnostic, Result, WrapErr};
//! use semver::Version;
//!
//! pub fn some_tool() -> Result<Version> {
//! Ok("1.2.x"
//! .parse()
//! .into_diagnostic()
//! .wrap_err("Parsing this tool's semver version failed.")?)
//! }
//! ```
//!
//! ### ... in `main()`
//!
//! `main()` is just like any other part of your application-internal code. Use
//! `Result` as your return value, and it will pretty-print your diagnostics
//! automatically.
//!
//! > **NOTE:** You must enable the `"fancy"` crate feature to get fancy report
//! output like in the screenshots here.** You should only do this in your
//! toplevel crate, as the fancy feature pulls in a number of dependencies that
//! libraries and such might not want.
//!
//! ```rust
//! use miette::{IntoDiagnostic, Result};
//! use semver::Version;
//!
//! fn pretend_this_is_main() -> Result<()> {
//! let version: Version = "1.2.x".parse().into_diagnostic()?;
//! println!("{}", version);
//! Ok(())
//! }
//! ```
//!
//! Please note: in order to get fancy diagnostic rendering with all the pretty
//! colors and arrows, you should install `miette` with the `fancy` feature
//! enabled:
//!
//! ```toml
//! miette = { version = "X.Y.Z", features = ["fancy"] }
//! ```
//!
//! ### ... diagnostic code URLs
//!
//! `miette` supports providing a URL for individual diagnostics. This URL will
//! be displayed as an actual link in supported terminals, like so:
//!
//! <img
//! src="https://raw.githubusercontent.com/zkat/miette/main/images/code_linking.png"
//! alt=" Example showing the graphical report printer for miette
//! pretty-printing an error code. The code is underlined and followed by text
//! saying to 'click here'. A hover tooltip shows a full-fledged URL that can be
//! Ctrl+Clicked to open in a browser.
//! \
//! This feature is also available in the narratable printer. It will add a line
//! after printing the error code showing a plain URL that you can visit.
//! ">
//!
//! To use this, you can add a `url()` sub-param to your `#[diagnostic]`
//! attribute:
//!
//! ```rust
//! use miette::Diagnostic;
//! use thiserror::Error;
//!
//! #[derive(Error, Diagnostic, Debug)]
//! #[error("kaboom")]
//! #[diagnostic(
//! code(my_app::my_error),
//! // You can do formatting!
//! url("https://my_website.com/error_codes#{}", self.code().unwrap())
//! )]
//! struct MyErr;
//! ```
//!
//! Additionally, if you're developing a library and your error type is exported
//! from your crate's top level, you can use a special `url(docsrs)` option
//! instead of manually constructing the URL. This will automatically create a
//! link to this diagnostic on `docs.rs`, so folks can just go straight to your
//! (very high quality and detailed!) documentation on this diagnostic:
//!
//! ```rust
//! use miette::Diagnostic;
//! use thiserror::Error;
//!
//! #[derive(Error, Diagnostic, Debug)]
//! #[diagnostic(
//! code(my_app::my_error),
//! // Will link users to https://docs.rs/my_crate/0.0.0/my_crate/struct.MyErr.html
//! url(docsrs)
//! )]
//! #[error("kaboom")]
//! struct MyErr;
//! ```
//!
//! ### ... snippets
//!
//! Along with its general error handling and reporting features, `miette` also
//! includes facilities for adding error spans/annotations/labels to your
//! output. This can be very useful when an error is syntax-related, but you can
//! even use it to print out sections of your own source code!
//!
//! To achieve this, `miette` defines its own lightweight [`SourceSpan`] type.
//! This is a basic byte-offset and length into an associated [`SourceCode`]
//! and, along with the latter, gives `miette` all the information it needs to
//! pretty-print some snippets! You can also use your own `Into<SourceSpan>`
//! types as label spans.
//!
//! The easiest way to define errors like this is to use the
//! `derive(Diagnostic)` macro:
//!
//! ```rust
//! use miette::{Diagnostic, SourceSpan};
//! use thiserror::Error;
//!
//! #[derive(Diagnostic, Debug, Error)]
//! #[error("oops")]
//! #[diagnostic(code(my_lib::random_error))]
//! pub struct MyErrorType {
//! // The `Source` that miette will use.
//! #[source_code]
//! src: String,
//!
//! // This will underline/mark the specific code inside the larger
//! // snippet context.
//! #[label = "This is the highlight"]
//! err_span: SourceSpan,
//!
//! // You can add as many labels as you want.
//! // They'll be rendered sequentially.
//! #[label("This is bad")]
//! snip2: (usize, usize), // `(usize, usize)` is `Into<SourceSpan>`!
//! }
//! ```
//!
//! ### ... multiple related errors
//!
//! `miette` supports collecting multiple errors into a single diagnostic, and
//! printing them all together nicely.
//!
//! To do so, use the `#[related]` tag on any `IntoIter` field in your
//! `Diagnostic` type:
//!
//! ```rust
//! use miette::Diagnostic;
//! use thiserror::Error;
//!
//! #[derive(Debug, Error, Diagnostic)]
//! #[error("oops")]
//! struct MyError {
//! #[related]
//! others: Vec<MyError>,
//! }
//! ```
//!
//! ### ... delayed source code
//!
//! Sometimes it makes sense to add source code to the error message later. One
//! option is to use [`with_source_code()`](Report::with_source_code) method for
//! that:
//!
//! ```rust,no_run
//! use miette::{Diagnostic, SourceSpan};
//! use thiserror::Error;
//!
//! #[derive(Diagnostic, Debug, Error)]
//! #[error("oops")]
//! #[diagnostic()]
//! pub struct MyErrorType {
//! // Note: label but no source code
//! #[label]
//! err_span: SourceSpan,
//! }
//!
//! fn do_something() -> miette::Result<()> {
//! // This function emits actual error with label
//! return Err(MyErrorType {
//! err_span: (7..11).into(),
//! })?;
//! }
//!
//! fn main() -> miette::Result<()> {
//! do_something().map_err(|error| {
//! // And this code provides the source code for inner error
//! error.with_source_code(String::from("source code"))
//! })
//! }
//! ```
//!
//! Also source code can be provided by a wrapper type. This is especially
//! useful in combination with `related`, when multiple errors should be emitted
//! at the same time:
//!
//! ```rust,no_run
//! use miette::{Diagnostic, Report, SourceSpan};
//! use thiserror::Error;
//!
//! #[derive(Diagnostic, Debug, Error)]
//! #[error("oops")]
//! #[diagnostic()]
//! pub struct InnerError {
//! // Note: label but no source code
//! #[label]
//! err_span: SourceSpan,
//! }
//!
//! #[derive(Diagnostic, Debug, Error)]
//! #[error("oops: multiple errors")]
//! #[diagnostic()]
//! pub struct MultiError {
//! // Note source code by no labels
//! #[source_code]
//! source_code: String,
//! // The source code above is used for these errors
//! #[related]
//! related: Vec<InnerError>,
//! }
//!
//! fn do_something() -> Result<(), Vec<InnerError>> {
//! Err(vec![
//! InnerError {
//! err_span: (0..6).into(),
//! },
//! InnerError {
//! err_span: (7..11).into(),
//! },
//! ])
//! }
//!
//! fn main() -> miette::Result<()> {
//! do_something().map_err(|err_list| MultiError {
//! source_code: "source code".into(),
//! related: err_list,
//! })?;
//! Ok(())
//! }
//! ```
//!
//! ### ... handler options
//!
//! [`MietteHandler`] is the default handler, and is very customizable. In most
//! cases, you can simply use [`MietteHandlerOpts`] to tweak its behavior
//! instead of falling back to your own custom handler.
//!
//! Usage is like so:
//!
//! ```rust
//! miette::set_hook(Box::new(|_| {
//! Box::new(
//! miette::MietteHandlerOpts::new()
//! .terminal_links(true)
//! .unicode(false)
//! .context_lines(3)
//! .tab_width(4)
//! .build(),
//! )
//! }))
//!
//! # .unwrap()
//! ```
//!
//! See the docs for [`MietteHandlerOpts`] for more details on what you can
//! customize!
//!
//! ## Acknowledgements
//!
//! `miette` was not developed in a void. It owes enormous credit to various
//! other projects and their authors:
//!
//! - [`anyhow`](http://crates.io/crates/anyhow) and [`color-eyre`](https://crates.io/crates/color-eyre):
//! these two enormously influential error handling libraries have pushed
//! forward the experience of application-level error handling and error
//! reporting. `miette`'s `Report` type is an attempt at a very very rough
//! version of their `Report` types.
//! - [`thiserror`](https://crates.io/crates/thiserror) for setting the standard
//! for library-level error definitions, and for being the inspiration behind
//! `miette`'s derive macro.
//! - `rustc` and [@estebank](https://github.com/estebank) for their
//! state-of-the-art work in compiler diagnostics.
//! - [`ariadne`](https://crates.io/crates/ariadne) for pushing forward how
//! _pretty_ these diagnostics can really look!
//!
//! ## License
//!
//! `miette` is released to the Rust community under the
//! [Apache license 2.0](./LICENSE).
//!
//! It also includes code taken from [`eyre`](https://github.com/yaahc/eyre),
//! and some from [`thiserror`](https://github.com/dtolnay/thiserror), also under
//! the Apache License. Some code is taken from
//! [`ariadne`](https://github.com/zesterer/ariadne), which is MIT licensed.
pub use miette_derive::*; pub use miette_derive::*;
pub use error::*; pub use error::*;