fix(windows): normalize paths with normpath instead of `std::fs::ca…

…nonicalize()` (#84)

On Windows, `std::fs::canonicalize()` [produces a weird type of path
that cannot be used with
`Command::current_dir()`](rust-lang/rust#42869).
This switches to using the
[`normpath`](https://docs.rs/normpath/latest/normpath/trait.PathExt.html#tymethod.normalize)
crate, which should avoid these issues.

Cargo.toml

@@ -20,6 +20,7 @@ env_logger = "0.11.0"
 genawaiter = { version = "0.99.1", default-features = false }
 log = "0.4.0"
 mdbook = { version = "0.4.35", default-features = false }
+normpath = "1.0.0, <1.2.0" # 1.2.0 raises MSRV to 1.74
 once_cell = "1.0.0"
 pulldown-cmark = { version = "0.10.0", default-features = false }
 pulldown-cmark-to-cmark = "13.0.0"

src/book.rs

@@ -1,5 +1,7 @@
 use std::{fs, path::PathBuf};
 
+use normpath::PathExt;
+
 pub struct Book<'book> {
     pub book: &'book mdbook::book::Book,
     pub root: PathBuf,
@@ -9,11 +11,11 @@ pub struct Book<'book> {
 
 impl<'book> Book<'book> {
     pub fn new(ctx: &'book mdbook::renderer::RenderContext) -> anyhow::Result<Self> {
-        let root = ctx.root.canonicalize()?;
-        let source_dir = ctx.source_dir().canonicalize()?;
+        let root = ctx.root.normalize()?.into_path_buf();
+        let source_dir = ctx.source_dir().normalize()?.into_path_buf();
 
         fs::create_dir_all(&ctx.destination)?;
-        let destination = ctx.destination.canonicalize()?;
+        let destination = ctx.destination.normalize()?.into_path_buf();
 
         Ok(Self {
             book: &ctx.book,

src/lib.rs

@@ -186,6 +186,7 @@ mod tests {
     };
 
     use mdbook::{BookItem, Renderer as _};
+    use normpath::PathExt;
     use once_cell::sync::Lazy;
     use regex::Regex;
     use tempfile::{tempfile, TempDir};
@@ -372,7 +373,7 @@ mod tests {
                 writeln!(&mut logs, "{err:#}").unwrap()
             }
 
-            let root = self.book.root.canonicalize().unwrap();
+            let root = self.book.root.normalize().unwrap().into_path_buf();
             let re = Regex::new(&format!(
                 r"(?P<root>{})|(?P<line>line\s+\d+)|(?P<page>page\s+\d+)",
                 root.display()
@@ -566,7 +567,7 @@ mod tests {
         insta::assert_snapshot!(book, @r###"
         ├─ log output
         │  INFO mdbook::book: Running the pandoc backend    
-        │  WARN mdbook_pandoc::preprocess: Unable to normalize link 'foobarbaz' in chapter 'Getting Started': Unable to canonicalize path: $ROOT/src/foobarbaz: No such file or directory (os error 2)    
+        │  WARN mdbook_pandoc::preprocess: Unable to normalize link 'foobarbaz' in chapter 'Getting Started': Unable to normalize path: $ROOT/src/foobarbaz: No such file or directory (os error 2)    
         │  WARN mdbook_pandoc: Unable to resolve one or more relative links within the book, consider setting the `hosted-html` option in `[output.pandoc]`    
         │  INFO mdbook_pandoc::pandoc::renderer: Wrote output to book/markdown/book.md    
         ├─ markdown/book.md

src/pandoc/renderer.rs

@@ -8,6 +8,7 @@ use std::{
 };
 
 use anyhow::Context as _;
+use normpath::PathExt;
 use tempfile::NamedTempFile;
 
 use crate::{
@@ -219,7 +220,7 @@ impl Renderer {
                     include_str!("filters/annotate-tables-with-column-widths.lua")
                 )?;
                 pandoc.arg("--lua-filter");
-                pandoc.arg(filter.path().canonicalize()?);
+                pandoc.arg(filter.path().normalize()?.as_path());
                 _filter_tempfile_guard = filter.into_temp_path();
             } else {
                 log::warn!(

src/preprocess.rs

@@ -18,6 +18,7 @@ use mdbook::{
     book::{BookItems, Chapter},
     BookItem,
 };
+use normpath::PathExt;
 use once_cell::sync::Lazy;
 use pulldown_cmark::{CodeBlockKind, CowStr, HeadingLevel, LinkType};
 use regex::Regex;
@@ -366,20 +367,21 @@ impl<'book> Preprocessor<'book> {
     /// - Uniquely corresponds to the file at the original path
     fn normalize_path(&self, path: &Path) -> anyhow::Result<NormalizedPath> {
         let absolute_path = path
-            .canonicalize()
+            .normalize()
             .or_else(|err| match path.extension() {
                 Some(extension) if extension == "html" => {
                     if path.file_stem().is_some_and(|name| name == "index") {
-                        if let Ok(path) = path.with_file_name("README.md").canonicalize() {
+                        if let Ok(path) = path.with_file_name("README.md").normalize() {
                             return Ok(path);
                         }
                     }
-                    path.with_extension("md").canonicalize()
+                    path.with_extension("md").normalize()
                 }
-                Some(extension) if extension == "md" => path.with_extension("html").canonicalize(),
+                Some(extension) if extension == "md" => path.with_extension("html").normalize(),
                 _ => Err(err),
             })
-            .with_context(|| format!("Unable to canonicalize path: {}", path.display()))?;
+            .with_context(|| format!("Unable to normalize path: {}", path.display()))?
+            .into_path_buf();
         let preprocessed_relative_path = absolute_path
             .strip_prefix(&self.ctx.book.source_dir)
             .or_else(|_| absolute_path.strip_prefix(&self.preprocessed))