feat(deps): move fancy reporter (and its deps) to a feature

BREAKING CHANGE: The default fancy reporter is no longer available unless you enable the "fancy" feature. This also means you will not be pulling in a bunch of deps if you are using miette for a library

Fixes: https://github.com/zkat/miette/issues/25

Cargo.toml

@@ -15,15 +15,16 @@ exclude = ["images/", "tests/", "miette-derive/"]
 thiserror = "1.0.26"
 miette-derive = { path = "miette-derive", version = "=2.2.1-alpha.0"}
 once_cell = "1.8.0"
-owo-colors = "2.0.0"
-atty = "0.2.14"
-ci_info = "0.14.2"
-textwrap = "0.14.2"
-term_size = "0.3.2"
-unicode-width = "0.1.8"
-supports-hyperlinks = "1.1.0"
-supports-color = "1.0.2"
-supports-unicode = "1.0.0"
+
+owo-colors = { version = "2.0.0", optional = true }
+atty = { version = "0.2.14", optional = true }
+ci_info = { version = "0.14.2", optional = true }
+textwrap = { version = "0.14.2", optional = true }
+term_size = { version = "0.3.2", optional = true }
+unicode-width = { version = "0.1.8", optional = true }
+supports-hyperlinks = { version = "1.1.0", optional = true }
+supports-color = { version = "1.0.2", optional = true }
+supports-unicode = { version = "1.0.0", optional = true }
 
 [dev-dependencies]
 semver = "1.0.4"
@@ -35,5 +36,19 @@ rustversion = "1.0"
 trybuild = { version = "1.0.19", features = ["diff"] }
 syn = { version = "1.0", features = ["full"] }
 
+[features]
+default = []
+fancy = [
+    "owo-colors",
+    "atty",
+    "ci_info",
+    "textwrap",
+    "term_size",
+    "unicode-width",
+    "supports-hyperlinks",
+    "supports-color",
+    "supports-unicode"
+]
+
 [workspace]
 members = ["miette-derive"]

README.md

@@ -66,6 +66,12 @@ Using [`cargo-edit`](https://crates.io/crates/cargo-edit):
 $ cargo add miette
 ```
 
+If you want to use the fancy printer in all these screenshots:
+
+```sh
+$ cargo add miette --features fancy
+```
+
 ## Example
 
 ```rust
@@ -240,6 +246,14 @@ fn pretend_this_is_main() -> Result<()> {
 }
 ```
 
+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

src/eyreish/mod.rs

@@ -26,7 +26,12 @@ pub use ReportHandler as EyreContext;
 #[allow(unreachable_pub)]
 pub use WrapErr as Context;
 
-use crate::{Diagnostic, MietteHandler};
+use crate::Diagnostic;
+#[cfg(feature = "fancy")]
+use crate::MietteHandler;
+#[cfg(not(feature = "fancy"))]
+use crate::NarratableReportHandler;
+
 use error::ErrorImpl;
 
 mod context;
@@ -87,7 +92,10 @@ fn capture_handler(error: &(dyn Diagnostic + 'static)) -> Box<dyn ReportHandler>
 }
 
 fn get_default_printer(_err: &(dyn Diagnostic + 'static)) -> Box<dyn ReportHandler + 'static> {
-    Box::new(MietteHandler::new())
+    #[cfg(feature = "fancy")]
+    return Box::new(MietteHandler::new());
+    #[cfg(not(feature = "fancy"))]
+    return Box::new(NarratableReportHandler::new());
 }
 
 impl dyn ReportHandler {

src/handlers/mod.rs

@@ -3,12 +3,16 @@ Reporters included with `miette`.
 */
 
 #[allow(unreachable_pub)]
+#[cfg(feature = "fancy")]
 pub use graphical::*;
 #[allow(unreachable_pub)]
 pub use narratable::*;
 #[allow(unreachable_pub)]
+#[cfg(feature = "fancy")]
 pub use theme::*;
 
+#[cfg(feature = "fancy")]
 mod graphical;
 mod narratable;
+#[cfg(feature = "fancy")]
 mod theme;

src/lib.rs

@@ -6,6 +6,7 @@ pub use miette_derive::*;
 
 pub use error::*;
 pub use eyreish::*;
+#[cfg(feature = "fancy")]
 pub use handler::*;
 pub use handlers::*;
 pub use named_source::*;
@@ -14,6 +15,7 @@ pub use protocol::*;
 mod chain;
 mod error;
 mod eyreish;
+#[cfg(feature = "fancy")]
 mod handler;
 mod handlers;
 mod named_source;

tests/narrated.rs

@@ -1,13 +1,18 @@
 use miette::{
-    Diagnostic, GraphicalReportHandler, GraphicalTheme, MietteError, NamedSource,
+    Diagnostic, MietteError, NamedSource,
     NarratableReportHandler, Report, SourceSpan,
 };
+
+#[cfg(feature = "fancy")]
+use miette::{GraphicalReportHandler, GraphicalTheme};
+
 use thiserror::Error;
 
 fn fmt_report(diag: Report) -> String {
     let mut out = String::new();
     // Mostly for dev purposes.
-    if std::env::var("STYLE").is_ok() {
+    if cfg!(feature = "fancy") && std::env::var("STYLE").is_ok() {
+        #[cfg(feature = "fancy")]
         GraphicalReportHandler::new_themed(GraphicalTheme::unicode())
             .render_report(&mut out, diag.as_ref())
             .unwrap();

tests/printer.rs

@@ -1,3 +1,5 @@
+#![cfg(feature = "fancy")]
+
 use miette::{
     Diagnostic, GraphicalReportHandler, GraphicalTheme, MietteError, NamedSource,
     NarratableReportHandler, Report, SourceSpan,