{"record":{"id":"c97cc5ec4386a294","repo":"slint-ui/slint","slug":"failed-to-convert-path-to-url-preview","errorCode":null,"errorMessage":"Failed to convert path to URL","messagePattern":"Failed to convert path to URL","errorType":"exception","errorClass":"std::io::Error","httpStatus":null,"severity":"error","filePath":"tools/lsp/preview.rs","lineNumber":1406,"sourceCode":"/// Otherwise the file is indeed missing.\n///\n/// In any way, register it as a dependency\nfn get_url_from_cache(url: &Url) -> std::io::Result<(SourceFileVersion, String)> {\n    PREVIEW_STATE.with_borrow_mut(|preview_state| {\n        preview_state.dependencies.insert(url.to_owned());\n\n        preview_state.source_code.get(url).map(|r| (r.version, r.code.clone())).ok_or(\n            std::io::Error::new(\n                std::io::ErrorKind::NotFound,\n                \"File not registered in Live-Preview!\",\n            ),\n        )\n    })\n}\n\nfn get_path_from_cache(path: &Path) -> std::io::Result<(SourceFileVersion, String)> {\n    let url = Url::from_file_path(path).map_err(|()| {\n        std::io::Error::new(std::io::ErrorKind::NotFound, \"Failed to convert path to URL\")\n    })?;\n    get_url_from_cache(&url)\n}\n\n#[derive(Copy, Clone, Debug, PartialEq, Eq)]\npub enum LoadBehavior {\n    /// We reload the preview, most likely because a file has changed\n    Reload,\n    /// Load the preview and make the window visible if it wasn't already.\n    Load,\n    /// Load the preview and make the window visible if it wasn't already.\n    LoadWithoutLiveData,\n    /// We show the preview because the user asked for it. The UI should become visible and focused if it wasn't already\n    BringWindowToFront,\n}\n\npub fn reload_preview() {\n    let pc = PREVIEW_STATE","sourceCodeStart":1388,"sourceCodeEnd":1424,"githubUrl":"https://github.com/slint-ui/slint/blob/3a7e700487dc74d404cad0726378053ab763d4e0/tools/lsp/preview.rs#L1388-L1424","documentation":"In tools/lsp/preview.rs, get_path_from_cache converts a filesystem path to a file:// URL with Url::from_file_path before consulting the preview cache. If the conversion fails (path is relative, or not an absolute path), it returns a NotFound io::Error \"Failed to convert path to URL\". from_file_path only accepts absolute paths, so any relative or malformed path input triggers this.","triggerScenarios":"Calling get_path_from_cache with a relative Path (e.g. \"src/main.slint\") or a path that cannot be represented as a file URL (empty path, non-absolute), which makes Url::from_file_path return Err(()).","commonSituations":"An editor or tool passes a workspace-relative path from configuration or a diagnostic instead of an absolute path; or a path built by string concatenation without canonicalization is handed to the preview lookup.","solutions":["Make the path absolute before calling: use std::fs::canonicalize or join it with the workspace root.","Verify the path exists and is absolute (path.is_absolute()) before lookup.","If the source is configuration, store absolute paths (or resolve them against the workspace root at ingestion)."],"exampleFix":"// before\nlet (version, code) = get_path_from_cache(Path::new(\"ui/app.slint\"))?;\n// after\nlet abs = std::fs::canonicalize(\"ui/app.slint\")?;\nlet (version, code) = get_path_from_cache(&abs)?;","handlingStrategy":"validation","validationCode":"fn ensure_absolute(path: &Path) -> std::io::Result<PathBuf> {\n    if path.is_absolute() { Ok(path.to_path_buf()) }\n    else { std::fs::canonicalize(path) }\n}","typeGuard":"fn is_abs_path(p: &Path) -> bool { p.is_absolute() && p.to_str().map_or(false, |s| !s.is_empty()) }","tryCatchPattern":"let path = ensure_absolute(path)?;\nlet (version, code) = get_path_from_cache(&path)\n    .map_err(|e| e.context(format!(\"preview lookup failed for {}\", path.display())))?;","preventionTips":["Canonicalize every path (std::fs::canonicalize) before converting to a Url.","Store absolute paths in editor configuration; resolve relative entries against the workspace root at load time.","Prefer Url::from_file_path only after asserting path.is_absolute()."],"tags":["url","path","lsp","live-preview"],"backgroundTag":"invalid-url-format","analyzedSha":"3a7e700487dc74d404cad0726378053ab763d4e0","analyzedAt":"2026-09-16T01:37:20.251Z","contentChangedAt":"2026-09-16T01:37:20.251Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}