fix(autoload): expand the dirsep placeholder in target-dir patterns

AutoloadGenerator.php builds the target-dir pattern by quoting the path
with a <dirsep> marker in place of the separators, then replacing the
quoted marker with [\\/]. The port kept that shape, but preg_quote()
here deliberately leaves < and > alone so the regex crate does not read
\< as a word boundary, so the replacement never matched and the pattern
came out as the literal {^Main<dirsep>Foo<dirsep>}.

A root package's target-dir was therefore never stripped from files,
classmap or exclude-from-classmap, and dumping one failed outright.
Split on the separators and quote each segment instead, so the marker
never passes through preg_quote() at all.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

2 files changed, 15 insertions, 21 deletions

diff --git a/crates/shirabe/src/autoload/autoload_generator.rs b/crates/shirabe/src/autoload/autoload_generator.rs
index 0f7fe22a..91df1749 100644
--- a/crates/shirabe/src/autoload/autoload_generator.rs
+++ b/crates/shirabe/src/autoload/autoload_generator.rs
@@ -1896,17 +1896,21 @@ class ComposerStaticInit{}
                     {
                         // remove target-dir from file paths of the root package
                         if is_root {
-                            let target_dir = str_replace(
-                                "\\<dirsep\\>",
-                                "[\\\\/]",
-                                &preg_quote(
-                                    &str_replace_multi(
-                                        &package.get_target_dir().unwrap_or_default(),
-                                        &[("/", "<dirsep>"), ("\\", "<dirsep>")],
-                                    ),
-                                    None,
-                                ),
-                            );
+                            // Regex pattern compatibility:
+                            // PHP swaps every path separator for a `<dirsep>` marker, runs
+                            // `preg_quote` over the whole target dir and rewrites the quoted
+                            // `\<dirsep\>` into `[\\/]`. `preg_quote` emits `<` and `>`
+                            // unescaped here, because the `regex` crate reads `\<`/`\>` as word
+                            // boundaries, so the marker is not recoverable from the quoted
+                            // string. Quote each separator-delimited segment on its own and join
+                            // the segments with the same character class.
+                            let target_dir = package
+                                .get_target_dir()
+                                .unwrap_or_default()
+                                .split(['/', '\\'])
+                                .map(|segment| preg_quote(segment, None))
+                                .collect::<Vec<String>>()
+                                .join("[\\\\/]");
                             path_str = ltrim(
                                 &Preg::replace(
                                     format!("{{^{}}}", target_dir),
@@ -2522,12 +2526,3 @@ fn find_top_level_arrow(entry: &str) -> Option<usize> {
     }
     None
 }
-
-// Helper used by parse_autoloads_type for chained string substitutions.
-fn str_replace_multi(input: &str, pairs: &[(&str, &str)]) -> String {
-    let mut s = input.to_string();
-    for (from, to) in pairs {
-        s = str_replace(from, to, &s);
-    }
-    s
-}
diff --git a/crates/shirabe/tests/autoload/autoload_generator_test.rs b/crates/shirabe/tests/autoload/autoload_generator_test.rs
index 3f2c142c..4efcc7e0 100644
--- a/crates/shirabe/tests/autoload/autoload_generator_test.rs
+++ b/crates/shirabe/tests/autoload/autoload_generator_test.rs
@@ -589,7 +589,6 @@ fn test_root_package_autoloading_alternative_vendor_dir() {
 
 #[test]
 #[serial]
-#[ignore = "autoload_real.php/autoload_static.php fixtures track a newer Composer template (single blank lines + $filesToLoad/$requireFile block) than the current AutoloadGenerator port emits; needs production template alignment"]
 fn test_root_package_autoloading_with_target_dir() {
     let mut s = set_up();
     let package = new_root_pkg("root/a");