rescript-lang
diff --git a/‎rewatch/src/build.rs‎
Lines changed: 53 additions & 2 deletions b/‎rewatch/src/build.rs‎
Lines changed: 53 additions & 2 deletions
diff --git a/‎rewatch/src/build/packages.rs‎
Lines changed: 121 additions & 2 deletions b/‎rewatch/src/build/packages.rs‎
Lines changed: 121 additions & 2 deletions
@@ -483,8 +483,21 @@ pub fn incremental_build(
 }
 
 fn log_config_warnings(build_state: &BuildCommandState) {
-    build_state.packages.iter().for_each(|(_, package)| {
-        // Only warn for local dependencies, not external packages
+    let mut packages: Vec<_> = build_state.packages.values().collect();
+    packages.sort_by(|a, b| a.name.cmp(&b.name));
+    packages.iter().for_each(|package| {
+        let deprecations = package.config.get_deprecations();
+        if !deprecations.is_empty() {
+            // External consumers can't fix deprecations themselves, so we
+            // point them at the package's issue tracker when we can find one.
+            let issue_tracker_url = if package.is_local_dep {
+                None
+            } else {
+                crate::build::packages::read_issue_tracker_url(&package.path)
+            };
+            log_deprecations(&package.name, deprecations, issue_tracker_url.as_deref());
+        }
+
         if package.is_local_dep {
             package
                 .config
@@ -501,6 +514,44 @@ fn log_config_warnings(build_state: &BuildCommandState) {
     });
 }
 
+fn log_deprecations(
+    package_name: &str,
+    deprecations: &[crate::config::DeprecationWarning],
+    issue_tracker_url: Option<&str>,
+) {
+    let mut message = format!(
+        "Package '{package_name}' uses deprecated config (support will be removed in a future version):"
+    );
+    for deprecation in deprecations {
+        let line = match deprecation {
+            crate::config::DeprecationWarning::BsconfigJson => {
+                "  - filename 'bsconfig.json' — rename to 'rescript.json'"
+            }
+            crate::config::DeprecationWarning::BsDependencies => {
+                "  - field 'bs-dependencies' — use 'dependencies' instead"
+            }
+            crate::config::DeprecationWarning::BsDevDependencies => {
+                "  - field 'bs-dev-dependencies' — use 'dev-dependencies' instead"
+            }
+            crate::config::DeprecationWarning::BscFlags => {
+                "  - field 'bsc-flags' — use 'compiler-flags' instead"
+            }
+            crate::config::DeprecationWarning::CjsModule => {
+                "  - module 'cjs' in package-specs — use 'commonjs' instead"
+            }
+            crate::config::DeprecationWarning::Es6Module => {
+                "  - module 'es6' in package-specs — use 'esmodule' instead"
+            }
+        };
+        message.push('\n');
+        message.push_str(line);
+    }
+    if let Some(url) = issue_tracker_url {
+        message.push_str(&format!("\nPlease report this to the package maintainer: {url}"));
+    }
+    eprintln!("\n{}", style(message).yellow());
+}
+
 fn log_unsupported_config_field(package_name: &str, field_name: &str) {
     let warning = format!(
         "The field '{field_name}' found in the package config of '{package_name}' is not supported by ReScript 12's new build system."
 
@@ -251,7 +251,13 @@ fn get_source_dirs(source: config::Source, sub_path: Option<PathBuf>) -> AHashSe
 
 pub fn read_config(package_dir: &Path) -> Result<Config> {
     let rescript_json_path = package_dir.join("rescript.json");
-    Config::new(&rescript_json_path)
+    let bsconfig_json_path = package_dir.join("bsconfig.json");
+
+    if rescript_json_path.exists() {
+        Config::new(&rescript_json_path)
+    } else {
+        Config::new(&bsconfig_json_path)
+    }
 }
 
 pub fn read_dependency(
@@ -451,12 +457,52 @@ pub fn read_package_name(package_dir: &Path) -> Result<String> {
         return Ok(name);
     }
 
+    if let Some(name) = read_name("bsconfig.json")? {
+        return Ok(name);
+    }
+
     Err(anyhow!(
         "No name field found in package.json or rescript.json in {}",
         package_dir.to_string_lossy()
     ))
 }
 
+/// Looks up the best-effort issue tracker URL for a package by reading its
+/// package.json, preferring `bugs.url`, then deriving from `repository`.
+/// Returns None if no tracker could be inferred.
+pub fn read_issue_tracker_url(package_dir: &Path) -> Option<String> {
+    let contents = fs::read_to_string(package_dir.join("package.json")).ok()?;
+    let json: serde_json::Value = serde_json::from_str(&contents).ok()?;
+
+    let extract_url = |v: &serde_json::Value| -> Option<String> {
+        match v {
+            serde_json::Value::String(s) => Some(s.to_owned()),
+            serde_json::Value::Object(o) => o.get("url").and_then(|u| u.as_str()).map(String::from),
+            _ => None,
+        }
+    };
+
+    if let Some(bugs_url) = json.get("bugs").and_then(extract_url) {
+        return Some(bugs_url);
+    }
+
+    json.get("repository")
+        .and_then(extract_url)
+        .map(|repo| issues_url_from_repository(&repo))
+}
+
+fn issues_url_from_repository(repo: &str) -> String {
+    let cleaned = repo.trim_start_matches("git+").trim_end_matches(".git");
+
+    // npm shorthand (no scheme, no user@): treat as github-style "owner/repo"
+    if !cleaned.contains("://") && !cleaned.contains('@') {
+        let path = cleaned.trim_start_matches("github:");
+        return format!("https://github.com/{path}/issues");
+    }
+
+    format!("{cleaned}/issues")
+}
+
 fn make_package(
     config: config::Config,
     package_path: &Path,
@@ -1100,7 +1146,7 @@ pub fn validate_packages_dependencies(packages: &AHashMap<String, Package>) -> b
 mod test {
     use crate::config;
 
-    use super::{Namespace, Package, read_package_name};
+    use super::{Namespace, Package, read_issue_tracker_url, read_package_name};
     use ahash::{AHashMap, AHashSet};
     use std::fs;
     use std::path::PathBuf;
@@ -1235,4 +1281,77 @@ mod test {
             )
         );
     }
+
+    fn write_pkg_json(dir: &std::path::Path, body: &str) {
+        fs::write(dir.join("package.json"), body).expect("package.json should be written");
+    }
+
+    #[test]
+    fn issue_tracker_url_prefers_bugs_url_string() {
+        let temp_dir = TempDir::new().unwrap();
+        write_pkg_json(
+            temp_dir.path(),
+            r#"{"name":"x","bugs":"https://example.com/issues"}"#,
+        );
+        assert_eq!(
+            read_issue_tracker_url(temp_dir.path()),
+            Some("https://example.com/issues".to_string())
+        );
+    }
+
+    #[test]
+    fn issue_tracker_url_prefers_bugs_object_url() {
+        let temp_dir = TempDir::new().unwrap();
+        write_pkg_json(
+            temp_dir.path(),
+            r#"{"name":"x","bugs":{"url":"https://example.com/report"}}"#,
+        );
+        assert_eq!(
+            read_issue_tracker_url(temp_dir.path()),
+            Some("https://example.com/report".to_string())
+        );
+    }
+
+    #[test]
+    fn issue_tracker_url_derives_from_repository_git_url() {
+        let temp_dir = TempDir::new().unwrap();
+        write_pkg_json(
+            temp_dir.path(),
+            r#"{"name":"x","repository":"git+https://github.com/owner/repo.git"}"#,
+        );
+        assert_eq!(
+            read_issue_tracker_url(temp_dir.path()),
+            Some("https://github.com/owner/repo/issues".to_string())
+        );
+    }
+
+    #[test]
+    fn issue_tracker_url_derives_from_repository_object() {
+        let temp_dir = TempDir::new().unwrap();
+        write_pkg_json(
+            temp_dir.path(),
+            r#"{"name":"x","repository":{"type":"git","url":"https://github.com/owner/repo.git"}}"#,
+        );
+        assert_eq!(
+            read_issue_tracker_url(temp_dir.path()),
+            Some("https://github.com/owner/repo/issues".to_string())
+        );
+    }
+
+    #[test]
+    fn issue_tracker_url_handles_shorthand() {
+        let temp_dir = TempDir::new().unwrap();
+        write_pkg_json(temp_dir.path(), r#"{"name":"x","repository":"owner/repo"}"#);
+        assert_eq!(
+            read_issue_tracker_url(temp_dir.path()),
+            Some("https://github.com/owner/repo/issues".to_string())
+        );
+    }
+
+    #[test]
+    fn issue_tracker_url_returns_none_without_hints() {
+        let temp_dir = TempDir::new().unwrap();
+        write_pkg_json(temp_dir.path(), r#"{"name":"x"}"#);
+        assert_eq!(read_issue_tracker_url(temp_dir.path()), None);
+    }
 }