fix(provider): emit drive-letter file URIs for Windows paths

crates/opy-provider/src/main.rs

@@ -17,6 +17,8 @@ use workshop_rs::program::MappedText;
 
 mod edits;
 mod navigation;
+mod uri;
+use uri::{file_uri_path, filesystem_path, path_to_file_uri};
 
 const PROTOCOL_VERSIONS: [&str; 7] = ["1.0", "1.1", "1.2", "1.3", "1.4", "1.5", "1.6"];
 const PROJECT_LOADING_VERSION: &str = "1.1";
@@ -1774,97 +1776,6 @@ fn resolved_path(root: &Path, path: &str) -> PathBuf {
     }
 }
 
-fn filesystem_path(value: &str) -> Option<PathBuf> {
-    if let Some(path) = value.strip_prefix("file://") {
-        let path = if path.starts_with('/') {
-            path
-        } else {
-            return None;
-        };
-        return Some(PathBuf::from(percent_decode(path)?));
-    }
-    // A `scheme:` prefix makes `value` a URI, not a filesystem path — a
-    // document URI like `untitled:Untitled-1` must not silently resolve
-    // against the provider's working directory. A single letter before ':'
-    // is a Windows drive (`C:`), not a scheme.
-    if let Some(end) = value.find(':') {
-        let scheme = &value[..end];
-        if scheme.len() > 1
-            && scheme.starts_with(|c: char| c.is_ascii_alphabetic())
-            && scheme
-                .chars()
-                .all(|c| c.is_ascii_alphanumeric() || matches!(c, '+' | '-' | '.'))
-        {
-            return None;
-        }
-    }
-    Some(PathBuf::from(value))
-}
-
-fn file_uri_path(value: &str) -> Option<PathBuf> {
-    let path = value.strip_prefix("file://")?;
-    if !path.starts_with('/') {
-        return None;
-    }
-    let path = percent_decode(path)?;
-    #[cfg(windows)]
-    let path = path
-        .strip_prefix('/')
-        .filter(|path| {
-            let bytes = path.as_bytes();
-            bytes.first().is_some_and(u8::is_ascii_alphabetic)
-                && bytes.get(1) == Some(&b':')
-                && bytes.get(2) == Some(&b'/')
-        })
-        .unwrap_or(&path);
-    Some(PathBuf::from(path))
-}
-
-fn percent_decode(value: &str) -> Option<String> {
-    let bytes = value.as_bytes();
-    let mut decoded = Vec::with_capacity(bytes.len());
-    let mut index = 0;
-    while index < bytes.len() {
-        if bytes[index] == b'%' {
-            let high = bytes
-                .get(index + 1)
-                .and_then(|byte| (*byte as char).to_digit(16))?;
-            let low = bytes
-                .get(index + 2)
-                .and_then(|byte| (*byte as char).to_digit(16))?;
-            decoded.push((high * 16 + low) as u8);
-            index += 3;
-        } else {
-            decoded.push(bytes[index]);
-            index += 1;
-        }
-    }
-    String::from_utf8(decoded).ok()
-}
-
-fn path_to_file_uri(path: &Path) -> String {
-    let raw = path_string(path);
-    let mut uri = String::from("file://");
-    for byte in raw.bytes() {
-        if byte.is_ascii_alphanumeric() || matches!(byte, b'-' | b'_' | b'.' | b'/' | b'~') {
-            uri.push(byte as char);
-        } else {
-            uri.push('%');
-            uri.push(
-                char::from_digit(u32::from(byte >> 4), 16)
-                    .expect("hex digit")
-                    .to_ascii_uppercase(),
-            );
-            uri.push(
-                char::from_digit(u32::from(byte & 0x0f), 16)
-                    .expect("hex digit")
-                    .to_ascii_uppercase(),
-            );
-        }
-    }
-    uri
-}
-
 fn ok(id: Value, result: Value) -> Value {
     json!({ "jsonrpc": "2.0", "id": id, "result": result })
 }
@@ -1901,26 +1812,6 @@ mod tests {
     use super::*;
     use std::fs;
 
-    #[test]
-    fn file_uri_round_trips_spaces_and_unicode() {
-        let path = Path::new("/project/中文 file.opy");
-        assert_eq!(
-            filesystem_path(&path_to_file_uri(path)),
-            Some(path.to_path_buf())
-        );
-    }
-
-    #[test]
-    fn file_uri_path_handles_windows_drive_letter_uris() {
-        let path = file_uri_path("file:///D:/path/to/project.opy").expect("file URI path");
-        let expected = if cfg!(windows) {
-            PathBuf::from("D:/path/to/project.opy")
-        } else {
-            PathBuf::from("/D:/path/to/project.opy")
-        };
-        assert_eq!(path, expected);
-    }
-
     #[test]
     fn initialize_advertises_only_implemented_capabilities() {
         let mut server = Server {

crates/opy-provider/src/uri.rs

@@ -0,0 +1,134 @@
+use std::path::{Path, PathBuf};
+
+pub(crate) fn filesystem_path(value: &str) -> Option<PathBuf> {
+    if value.starts_with("file://") {
+        return file_uri_path(value);
+    }
+    // A `scheme:` prefix makes `value` a URI, not a filesystem path — a
+    // document URI like `untitled:Untitled-1` must not silently resolve
+    // against the provider's working directory. A single letter before ':'
+    // is a Windows drive (`C:`), not a scheme.
+    if let Some(end) = value.find(':') {
+        let scheme = &value[..end];
+        if scheme.len() > 1
+            && scheme.starts_with(|c: char| c.is_ascii_alphabetic())
+            && scheme
+                .chars()
+                .all(|c| c.is_ascii_alphanumeric() || matches!(c, '+' | '-' | '.'))
+        {
+            return None;
+        }
+    }
+    Some(PathBuf::from(value))
+}
+
+pub(crate) fn file_uri_path(value: &str) -> Option<PathBuf> {
+    let path = value.strip_prefix("file://")?;
+    if !path.starts_with('/') {
+        return None;
+    }
+    let path = percent_decode(path)?;
+    #[cfg(windows)]
+    let path = path
+        .strip_prefix('/')
+        .filter(|path| {
+            let bytes = path.as_bytes();
+            bytes.first().is_some_and(u8::is_ascii_alphabetic)
+                && bytes.get(1) == Some(&b':')
+                && bytes.get(2) == Some(&b'/')
+        })
+        .unwrap_or(&path);
+    Some(PathBuf::from(path))
+}
+
+fn percent_decode(value: &str) -> Option<String> {
+    let bytes = value.as_bytes();
+    let mut decoded = Vec::with_capacity(bytes.len());
+    let mut index = 0;
+    while index < bytes.len() {
+        if bytes[index] == b'%' {
+            let high = bytes
+                .get(index + 1)
+                .and_then(|byte| (*byte as char).to_digit(16))?;
+            let low = bytes
+                .get(index + 2)
+                .and_then(|byte| (*byte as char).to_digit(16))?;
+            decoded.push((high * 16 + low) as u8);
+            index += 3;
+        } else {
+            decoded.push(bytes[index]);
+            index += 1;
+        }
+    }
+    String::from_utf8(decoded).ok()
+}
+
+pub(crate) fn path_to_file_uri(path: &Path) -> String {
+    // Windows paths arrive as `E:\dir\f` or the verbatim `\\?\E:\dir\f`; the
+    // URI form is `file:///E:/dir/f`.
+    let raw = path.to_string_lossy().into_owned();
+    let raw = raw.strip_prefix(r"\\?\").unwrap_or(&raw).replace('\\', "/");
+    let drive = raw.as_bytes().first().is_some_and(u8::is_ascii_alphabetic)
+        && raw.as_bytes().get(1) == Some(&b':');
+    let mut uri = String::from(if drive { "file:///" } else { "file://" });
+    if drive {
+        uri.push_str(&raw[..2]);
+    }
+    for byte in raw[if drive { 2 } else { 0 }..].bytes() {
+        if byte.is_ascii_alphanumeric() || matches!(byte, b'-' | b'_' | b'.' | b'/' | b'~') {
+            uri.push(byte as char);
+        } else {
+            uri.push('%');
+            uri.push(
+                char::from_digit(u32::from(byte >> 4), 16)
+                    .expect("hex digit")
+                    .to_ascii_uppercase(),
+            );
+            uri.push(
+                char::from_digit(u32::from(byte & 0x0f), 16)
+                    .expect("hex digit")
+                    .to_ascii_uppercase(),
+            );
+        }
+    }
+    uri
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn file_uri_round_trips_spaces_and_unicode() {
+        let path = Path::new("/project/中文 file.opy");
+        assert_eq!(
+            filesystem_path(&path_to_file_uri(path)),
+            Some(path.to_path_buf())
+        );
+    }
+
+    #[test]
+    fn file_uri_encodes_windows_paths_with_a_drive_and_no_host() {
+        for raw in [
+            r"E:\Work\Bastion\src\main.opy",
+            r"\\?\E:\Work\Bastion\src\main.opy",
+            "E:/Work/Bastion/src/main.opy",
+        ] {
+            assert_eq!(
+                path_to_file_uri(Path::new(raw)),
+                "file:///E:/Work/Bastion/src/main.opy"
+            );
+        }
+    }
+
+    #[test]
+    fn file_uri_path_handles_windows_drive_letter_uris() {
+        let path = file_uri_path("file:///D:/path/to/project.opy").expect("file URI path");
+        let expected = if cfg!(windows) {
+            PathBuf::from("D:/path/to/project.opy")
+        } else {
+            PathBuf::from("/D:/path/to/project.opy")
+        };
+        assert_eq!(path, expected);
+    }
+}