+ "markdownDescription": "Configure a command that rust-analyzer can invoke to\nobtain configuration.\n\nThis is an alternative to manually generating\n`rust-project.json`: it enables rust-analyzer to generate\nrust-project.json on the fly, and regenerate it when\nswitching or modifying projects.\n\nThis is an object with three fields:\n\n* `command`: the shell command to invoke\n\n* `filesToWatch`: which build system-specific files should\nbe watched to trigger regenerating the configuration\n\n* `progressLabel`: the name of the command, used in\nprogress indicators in the IDE\n\nHere's an example of a valid configuration:\n\n```json\n\"rust-analyzer.workspace.discoverConfig\": {\n \"command\": [\n \"rust-project\",\n \"develop-json\",\n \"{arg}\"\n ],\n \"progressLabel\": \"buck2/rust-project\",\n \"filesToWatch\": [\n \"BUCK\"\n ]\n}\n```\n\n## Argument Substitutions\n\nIf `command` includes the argument `{arg}`, that argument will be substituted\nwith the JSON-serialized form of the following enum:\n\n```norun\n#[derive(PartialEq, Clone, Debug, Serialize)]\n#[serde(rename_all = \"camelCase\")]\npub enum DiscoverArgument {\n Path(AbsPathBuf),\n Buildfile(AbsPathBuf),\n}\n```\n\nrust-analyzer will use the path invocation to find and\ngenerate a `rust-project.json` and therefore a\nworkspace. Example:\n\n\n```norun\nrust-project develop-json '{ \"path\": \"myproject/src/main.rs\" }'\n```\n\nrust-analyzer will use build file invocations to update an\nexisting workspace. Example:\n\nOr with a build file and the configuration above:\n\n```norun\nrust-project develop-json '{ \"buildfile\": \"myproject/BUCK\" }'\n```\n\nAs a reference for implementors, buck2's `rust-project`\nwill likely be useful:\n<https://github.com/facebook/buck2/tree/main/integrations/rust-project>.\n\n## Discover Command Output\n\n**Warning**: This format is provisional and subject to change.\n\nThe discover command should output JSON objects to stdout,\none per line (JSONL format). These objects should correspond\nto this Rust data type:\n\n```norun\n#[derive(Debug, Clone, Deserialize, Serialize)]\n#[serde(tag = \"kind\")]\n#[serde(rename_all = \"snake_case\")]\nenum DiscoverProjectData {\n Finished { buildfile: Utf8PathBuf, project: ProjectJsonData },\n Error { error: String, source: Option<String> },\n Progress { message: String },\n}\n```\n\nFor example, a progress event:\n\n```json\n{\"kind\":\"progress\",\"message\":\"generating rust-project.json\"}\n```\n\nA finished event can look like this (expanded and\ncommented for readability):\n\n```json\n{\n // the internally-tagged representation of the enum.\n \"kind\": \"finished\",\n // the file used by a non-Cargo build system to define\n // a package or target.\n \"buildfile\": \"rust-analyzer/BUCK\",\n // the contents of a rust-project.json, elided for brevity\n \"project\": {\n \"sysroot\": \"foo\",\n \"crates\": []\n }\n}\n```\n\nOnly the finished event is required, but the other\nvariants are encouraged to give users more feedback about\nprogress or errors.\n\nStderr is not parsed as JSONL. It is treated as command log\noutput and forwarded to rust-analyzer's own logs.",