stringtables: preserve comments (#827)

libs/stringtable/Cargo.toml

@@ -15,8 +15,9 @@ hemtt-workspace = { path = "../workspace", version = "1.0.0" }
 automod = { workspace = true }
 linkme = { workspace = true }
 paste = { workspace = true }
-quick-xml = { version = "0.36.2", features = ["serialize"] }
+quick-xml = { version = "0.37.0", features = ["serialize"] }
 serde = { workspace = true, features = ["derive"] }
+serde-aux = "4.5.0"
 toml = { workspace = true }
 tracing = { workspace = true }
 

libs/stringtable/src/lib.rs

@@ -1,3 +1,5 @@
+use std::io::BufReader;
+
 use quick_xml::se::Serializer;
 use serde::{Deserialize, Serialize};
 
@@ -9,13 +11,17 @@ mod totals;
 pub use key::Key;
 pub use package::Package;
 pub use totals::Totals;
+use tracing::error;
 
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct Project {
     #[serde(rename = "@name")]
     name: String,
     #[serde(rename = "Package")]
     packages: Vec<Package>,
+
+    #[serde(skip)]
+    meta_comments: Vec<(String, String)>,
 }
 
 impl Project {
@@ -39,28 +45,76 @@ impl Project {
     /// Read a Project from a reader
     ///
     /// # Errors
-    /// [`quick_xml::de::DeError`] if the reader is not a valid stringtable
+    /// [`quick_xml::DeError`] if the reader is not a valid stringtable
     pub fn from_reader<R: std::io::BufRead>(reader: R) -> Result<Self, quick_xml::de::DeError> {
-        quick_xml::de::from_reader(reader)
+        let mut buffer = String::new();
+        let mut reading_comments = false;
+        let mut comments = Vec::new();
+        let Ok(reader) = reader
+            .lines()
+            .map(|l| {
+                let Ok(l) = l else {
+                    error!("Failed to read line: {:?}", l);
+                    return l;
+                };
+                if !reading_comments && !buffer.is_empty() {
+                    comments.push((buffer.trim().to_string(), l.trim().to_string()));
+                    buffer.clear();
+                }
+                if l.trim().starts_with("<!--") {
+                    reading_comments = true;
+                }
+                if reading_comments {
+                    buffer.push_str(&l);
+                    if l.trim().ends_with("-->") {
+                        reading_comments = false;
+                    }
+                }
+                Ok(l)
+            })
+            .collect::<Result<Vec<_>, _>>()
+        else {
+            return Err(quick_xml::de::DeError::Custom(
+                "Failed to read lines".to_string(),
+            ));
+        };
+        comments.sort();
+        comments.dedup();
+        let mut this: Self =
+            quick_xml::de::from_reader(BufReader::new(reader.join("\n").as_bytes()))?;
+        this.meta_comments = comments;
+        Ok(this)
     }
 
     /// Write a Project to a writer
     ///
     /// # Errors
-    /// [`quick_xml::ser::Error`] if the writer fails to write
-    pub fn to_writer<W: std::fmt::Write>(
-        &self,
-        writer: &mut W,
-    ) -> Result<(), quick_xml::de::DeError> {
-        // If this write fails, the serializer will also throw an error
-        let _ = writer.write_str(r#"<?xml version="1.0" encoding="utf-8"?>"#);
-        let _ = writer.write_char('\n');
+    /// [`quick_xml::SeError`] if the writer fails to write
+    pub fn to_writer<W: std::fmt::Write>(&self, writer: &mut W) -> Result<(), quick_xml::SeError> {
+        writer.write_str(r#"<?xml version="1.0" encoding="utf-8"?>"#)?;
+        writer.write_char('\n')?;
         let mut buffer = String::new();
         let mut ser = Serializer::new(&mut buffer);
         ser.indent(' ', 4);
         self.serialize(ser)?;
         buffer.push('\n');
-        writer.write_str(&buffer)?;
+
+        for line in buffer.lines() {
+            for (before, after) in &self.meta_comments {
+                if line.trim().starts_with(after) {
+                    let whitespace = line
+                        .chars()
+                        .take_while(|c| c.is_whitespace())
+                        .collect::<String>();
+                    writer.write_str(&whitespace)?;
+                    writer.write_str(before)?;
+                    writer.write_char('\n')?;
+                }
+            }
+            writer.write_str(line)?;
+            writer.write_char('\n')?;
+        }
+
         Ok(())
     }
 }

libs/stringtable/tests/snapshots/ace_arsenal__sort-2.snap

@@ -6127,4 +6127,5 @@ Project {
             containers: [],
         },
     ],
+    meta_comments: [],
 }

libs/stringtable/tests/snapshots/ace_arsenal__sort.snap

@@ -6127,4 +6127,5 @@ Project {
             containers: [],
         },
     ],
+    meta_comments: [],
 }