Move renderer types to mdbook-renderer

This sets up mdbook-renderer with the intent of being the core
library that renderers use to implement the necessary interactions.

Cargo.lock

@@ -1272,6 +1272,7 @@ dependencies = [
  "log",
  "mdbook-core",
  "mdbook-preprocessor",
+ "mdbook-renderer",
  "mdbook-summary",
  "memchr",
  "notify",
@@ -1334,7 +1335,10 @@ dependencies = [
 name = "mdbook-renderer"
 version = "0.5.0-alpha.1"
 dependencies = [
+ "anyhow",
  "mdbook-core",
+ "serde",
+ "serde_json",
 ]
 
 [[package]]

Cargo.toml

@@ -25,6 +25,7 @@ anyhow = "1.0.98"
 log = "0.4.27"
 mdbook-core = { path = "crates/mdbook-core" }
 mdbook-preprocessor = { path = "crates/mdbook-preprocessor" }
+mdbook-renderer = { path = "crates/mdbook-renderer" }
 mdbook-summary = { path = "crates/mdbook-summary" }
 memchr = "2.7.5"
 pulldown-cmark = { version = "0.10.3", default-features = false, features = ["html"] } # Do not update, part of the public api.
@@ -63,6 +64,7 @@ hex = "0.4.3"
 log.workspace = true
 mdbook-core.workspace = true
 mdbook-preprocessor.workspace = true
+mdbook-renderer.workspace = true
 mdbook-summary.workspace = true
 memchr.workspace = true
 opener = "0.8.1"

crates/mdbook-renderer/Cargo.toml

@@ -8,7 +8,10 @@ repository.workspace = true
 rust-version.workspace = true
 
 [dependencies]
+anyhow.workspace = true
 mdbook-core.workspace = true
+serde.workspace = true
+serde_json.workspace = true
 
 [lints]
 workspace = true

crates/mdbook-renderer/src/lib.rs

@@ -1,3 +1,81 @@
 //! Library to assist implementing an mdbook renderer.
 
+use anyhow::Context;
+use mdbook_core::book::Book;
+use mdbook_core::config::Config;
+use mdbook_core::errors::Result;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::io::Read;
+use std::path::PathBuf;
+
 pub use mdbook_core::MDBOOK_VERSION;
+pub use mdbook_core::book;
+pub use mdbook_core::config;
+pub use mdbook_core::errors;
+
+/// An mdbook backend.
+pub trait Renderer {
+    /// The `Renderer`'s name.
+    fn name(&self) -> &str;
+
+    /// Invoke the `Renderer`, passing in all the necessary information for
+    /// describing a book.
+    fn render(&self, ctx: &RenderContext) -> Result<()>;
+}
+
+/// The context provided to all renderers.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct RenderContext {
+    /// Which version of `mdbook` did this come from (as written in `mdbook`'s
+    /// `Cargo.toml`). Useful if you know the renderer is only compatible with
+    /// certain versions of `mdbook`.
+    pub version: String,
+    /// The book's root directory.
+    pub root: PathBuf,
+    /// A loaded representation of the book itself.
+    pub book: Book,
+    /// The loaded configuration file.
+    pub config: Config,
+    /// Where the renderer *must* put any build artefacts generated. To allow
+    /// renderers to cache intermediate results, this directory is not
+    /// guaranteed to be empty or even exist.
+    pub destination: PathBuf,
+    /// Internal mapping of chapter titles.
+    ///
+    /// This is used internally by mdbook to compute custom chapter titles.
+    /// This should not be used outside of mdbook's internals.
+    #[serde(skip)]
+    pub chapter_titles: HashMap<PathBuf, String>,
+    #[serde(skip)]
+    __non_exhaustive: (),
+}
+
+impl RenderContext {
+    /// Create a new `RenderContext`.
+    pub fn new<P, Q>(root: P, book: Book, config: Config, destination: Q) -> RenderContext
+    where
+        P: Into<PathBuf>,
+        Q: Into<PathBuf>,
+    {
+        RenderContext {
+            book,
+            config,
+            version: crate::MDBOOK_VERSION.to_string(),
+            root: root.into(),
+            destination: destination.into(),
+            chapter_titles: HashMap::new(),
+            __non_exhaustive: (),
+        }
+    }
+
+    /// Get the source directory's (absolute) path on disk.
+    pub fn source_dir(&self) -> PathBuf {
+        self.root.join(&self.config.book.src)
+    }
+
+    /// Load a `RenderContext` from its JSON representation.
+    pub fn from_json<R: Read>(reader: R) -> Result<RenderContext> {
+        serde_json::from_reader(reader).with_context(|| "Unable to deserialize the `RenderContext`")
+    }
+}

src/book/mod.rs

@@ -16,6 +16,7 @@ pub use mdbook_core::book::{Book, BookItem, BookItems, Chapter, SectionNumber};
 use mdbook_core::config::{Config, RustEdition};
 use mdbook_core::utils;
 use mdbook_preprocessor::{Preprocessor, PreprocessorContext};
+use mdbook_renderer::{RenderContext, Renderer};
 pub use mdbook_summary::{Link, Summary, SummaryItem, parse_summary};
 use std::ffi::OsString;
 use std::io::{IsTerminal, Write};
@@ -26,7 +27,7 @@ use toml::Value;
 use topological_sort::TopologicalSort;
 
 use crate::preprocess::{CmdPreprocessor, IndexPreprocessor, LinkPreprocessor};
-use crate::renderer::{CmdRenderer, HtmlHandlebars, MarkdownRenderer, RenderContext, Renderer};
+use crate::renderer::{CmdRenderer, HtmlHandlebars, MarkdownRenderer};
 
 /// The object used to manage and build a book.
 pub struct MDBook {

src/lib.rs

@@ -76,7 +76,7 @@
 //! access to the various methods for working with the [`Config`].
 //!
 //! [user guide]: https://rust-lang.github.io/mdBook/
-//! [`RenderContext`]: renderer::RenderContext
+//! [`RenderContext`]: mdbook_renderer::RenderContext
 //! [relevant chapter]: https://rust-lang.github.io/mdBook/for_developers/backends.html
 //! [`Config`]: mdbook_core::config::Config
 
@@ -88,6 +88,5 @@ pub mod theme;
 
 pub use crate::book::BookItem;
 pub use crate::book::MDBook;
-pub use crate::renderer::Renderer;
 pub use mdbook_core::MDBOOK_VERSION;
 pub use mdbook_core::config::Config;

src/renderer/mod.rs

@@ -11,15 +11,12 @@
 //! [For Developers]: https://rust-lang.github.io/mdBook/for_developers/index.html
 //! [RenderContext]: struct.RenderContext.html
 
-use crate::book::Book;
 use anyhow::{Context, Result, bail};
 use log::{error, info, trace, warn};
-use mdbook_core::config::Config;
-use serde::{Deserialize, Serialize};
+use mdbook_renderer::{RenderContext, Renderer};
 use shlex::Shlex;
-use std::collections::HashMap;
 use std::fs;
-use std::io::{self, ErrorKind, Read};
+use std::io::{self, ErrorKind};
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 use toml::Value;
@@ -30,76 +27,6 @@ pub use self::markdown_renderer::MarkdownRenderer;
 mod html_handlebars;
 mod markdown_renderer;
 
-/// An arbitrary `mdbook` backend.
-///
-/// Although it's quite possible for you to import `mdbook` as a library and
-/// provide your own renderer, there are two main renderer implementations that
-/// 99% of users will ever use:
-///
-/// - [`HtmlHandlebars`] - the built-in HTML renderer
-/// - [`CmdRenderer`] - a generic renderer which shells out to a program to do the
-///   actual rendering
-pub trait Renderer {
-    /// The `Renderer`'s name.
-    fn name(&self) -> &str;
-
-    /// Invoke the `Renderer`, passing in all the necessary information for
-    /// describing a book.
-    fn render(&self, ctx: &RenderContext) -> Result<()>;
-}
-
-/// The context provided to all renderers.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct RenderContext {
-    /// Which version of `mdbook` did this come from (as written in `mdbook`'s
-    /// `Cargo.toml`). Useful if you know the renderer is only compatible with
-    /// certain versions of `mdbook`.
-    pub version: String,
-    /// The book's root directory.
-    pub root: PathBuf,
-    /// A loaded representation of the book itself.
-    pub book: Book,
-    /// The loaded configuration file.
-    pub config: Config,
-    /// Where the renderer *must* put any build artefacts generated. To allow
-    /// renderers to cache intermediate results, this directory is not
-    /// guaranteed to be empty or even exist.
-    pub destination: PathBuf,
-    #[serde(skip)]
-    pub(crate) chapter_titles: HashMap<PathBuf, String>,
-    #[serde(skip)]
-    __non_exhaustive: (),
-}
-
-impl RenderContext {
-    /// Create a new `RenderContext`.
-    pub fn new<P, Q>(root: P, book: Book, config: Config, destination: Q) -> RenderContext
-    where
-        P: Into<PathBuf>,
-        Q: Into<PathBuf>,
-    {
-        RenderContext {
-            book,
-            config,
-            version: crate::MDBOOK_VERSION.to_string(),
-            root: root.into(),
-            destination: destination.into(),
-            chapter_titles: HashMap::new(),
-            __non_exhaustive: (),
-        }
-    }
-
-    /// Get the source directory's (absolute) path on disk.
-    pub fn source_dir(&self) -> PathBuf {
-        self.root.join(&self.config.book.src)
-    }
-
-    /// Load a `RenderContext` from its JSON representation.
-    pub fn from_json<R: Read>(reader: R) -> Result<RenderContext> {
-        serde_json::from_reader(reader).with_context(|| "Unable to deserialize the `RenderContext`")
-    }
-}
-
 /// A generic renderer which will shell out to an arbitrary executable.
 ///
 /// # Rendering Protocol

tests/testsuite/renderer.rs

@@ -2,7 +2,7 @@
 
 use crate::prelude::*;
 use anyhow::Result;
-use mdbook::renderer::{RenderContext, Renderer};
+use mdbook_renderer::{RenderContext, Renderer};
 use snapbox::IntoData;
 use std::fs::File;
 use std::sync::{Arc, Mutex};