fix(mfe): avoid crashing if unsupported mfe version found

crates/turborepo-lib/src/micro_frontends.rs

@@ -1,5 +1,6 @@
 use std::collections::{HashMap, HashSet};
 
+use tracing::warn;
 use turbopath::AbsoluteSystemPath;
 use turborepo_micro_frontend::{Config as MFEConfig, Error, DEFAULT_MICRO_FRONTENDS_CONFIG};
 use turborepo_repository::package_graph::PackageGraph;
@@ -21,7 +22,15 @@ impl MicroFrontendsConfigs {
             let config_path = repo_root
                 .resolve(package_info.package_path())
                 .join_component(DEFAULT_MICRO_FRONTENDS_CONFIG);
-            let Some(config) = MFEConfig::load(&config_path)? else {
+            let Some(config) = MFEConfig::load(&config_path).or_else(|err| {
+                if matches!(err, turborepo_micro_frontend::Error::UnsupportedVersion(_)) {
+                    warn!("Ignoring {config_path}: {err}");
+                    Ok(None)
+                } else {
+                    Err(err)
+                }
+            })?
+            else {
                 continue;
             };
             let tasks = config

crates/turborepo-micro-frontend/Cargo.toml

@@ -17,6 +17,7 @@ turbopath = { workspace = true }
 turborepo-errors = { workspace = true }
 
 [dev-dependencies]
+insta = { workspace = true }
 pretty_assertions = { workspace = true }
 
 [lints]

crates/turborepo-micro-frontend/src/error.rs

@@ -1,11 +1,18 @@
 use turborepo_errors::ParseDiagnostic;
 
+use crate::SUPPORTED_VERSIONS;
+
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("Unable to read configuration file: {0}")]
     Io(#[from] std::io::Error),
     #[error("Unable to parse JSON: {0}")]
     JsonParse(String),
+    #[error(
+        "Unsupported micro-frontends configuration version: {0}. Supported versions: \
+         {SUPPORTED_VERSIONS:?}"
+    )]
+    UnsupportedVersion(String),
 }
 
 impl Error {

crates/turborepo-micro-frontend/src/lib.rs

@@ -15,6 +15,7 @@ use turbopath::AbsoluteSystemPath;
 pub const DEFAULT_MICRO_FRONTENDS_CONFIG: &str = "micro-frontends.jsonc";
 pub const MICRO_FRONTENDS_PACKAGES: &[&str] = [MICRO_FRONTENDS_PACKAGE_INTERNAL].as_slice();
 pub const MICRO_FRONTENDS_PACKAGE_INTERNAL: &str = "@vercel/micro-frontends-internal";
+pub const SUPPORTED_VERSIONS: &[&str] = ["1"].as_slice();
 
 /// The minimal amount of information Turborepo needs to correctly start a local
 /// proxy server for microfrontends
@@ -31,11 +32,28 @@ impl Config {
         let Some(contents) = config_path.read_existing_to_string()? else {
             return Ok(None);
         };
-        let config = Self::from_str(&contents, config_path.as_str()).map_err(Error::biome_error)?;
+        let config = Self::from_str(&contents, config_path.as_str())?;
         Ok(Some(config))
     }
 
-    pub fn from_str(input: &str, source: &str) -> Result<Self, Vec<biome_diagnostics::Error>> {
+    pub fn from_str(input: &str, source: &str) -> Result<Self, Error> {
+        #[derive(Deserializable, Default)]
+        struct VersionOnly {
+            version: String,
+        }
+        let (version_only, _errs) = biome_deserialize::json::deserialize_from_json_str(
+            input,
+            JsonParserOptions::default().with_allow_comments(),
+            source,
+        )
+        .consume();
+        // If parsing just the version fails, fallback to full schema to provide better
+        // error message
+        if let Some(VersionOnly { version }) = version_only {
+            if !SUPPORTED_VERSIONS.contains(&version.as_str()) {
+                return Err(Error::UnsupportedVersion(version));
+            }
+        }
         let (config, errs) = biome_deserialize::json::deserialize_from_json_str(
             input,
             JsonParserOptions::default().with_allow_comments(),
@@ -45,7 +63,7 @@ impl Config {
         if let Some(config) = config {
             Ok(config)
         } else {
-            Err(errs)
+            Err(Error::biome_error(errs))
         }
     }
 }
@@ -63,6 +81,8 @@ pub struct Development {
 
 #[cfg(test)]
 mod test {
+    use insta::assert_snapshot;
+
     use super::*;
 
     #[test]
@@ -71,4 +91,11 @@ mod test {
         let example_config = Config::from_str(input, "something.json");
         assert!(example_config.is_ok());
     }
+
+    #[test]
+    fn test_unsupported_version() {
+        let input = r#"{"version": "yolo"}"#;
+        let err = Config::from_str(input, "something.json").unwrap_err();
+        assert_snapshot!(err, @r###"Unsupported micro-frontends configuration version: yolo. Supported versions: ["1"]"###);
+    }
 }