Add support for local language configuration (#1249)

* add local configuration

* move config loading to Application::new

* simplify find_root_impl

4 files changed, 66 insertions, 17 deletions

diff --git a/helix-loader/Cargo.toml b/helix-loader/Cargo.toml
index 21b37333..607d1a0a 100644
--- a/helix-loader/Cargo.toml
+++ b/helix-loader/Cargo.toml
@@ -18,6 +18,8 @@ tree-sitter = "0.20"
 libloading = "0.7"
 once_cell = "1.9"
 
+log = "0.4"
+
 # cloning/compiling tree-sitter grammars
 cc = { version = "1" }
 threadpool = { version = "1.0" }
diff --git a/helix-loader/src/config.rs b/helix-loader/src/config.rs
new file mode 100644
index 00000000..3d71baed
--- /dev/null
+++ b/helix-loader/src/config.rs
@@ -0,0 +1,26 @@
+/// Default bultin-in languages.toml.
+pub fn default_lang_config() -> toml::Value {
+    toml::from_slice(include_bytes!("../../languages.toml"))
+        .expect("Could not parse bultin-in languages.toml to valid toml")
+}
+
+/// User configured languages.toml file, merged with the default config.
+pub fn user_lang_config() -> Result<toml::Value, toml::de::Error> {
+    let config = crate::local_config_dirs()
+        .into_iter()
+        .chain([crate::config_dir()].into_iter())
+        .map(|path| path.join("languages.toml"))
+        .filter_map(|file| {
+            std::fs::read(&file)
+                .map(|config| toml::from_slice(&config))
+                .ok()
+        })
+        .collect::<Result<Vec<_>, _>>()?
+        .into_iter()
+        .chain([default_lang_config()].into_iter())
+        .fold(toml::Value::Table(toml::value::Table::default()), |a, b| {
+            crate::merge_toml_values(b, a)
+        });
+
+    Ok(config)
+}
diff --git a/helix-loader/src/grammar.rs b/helix-loader/src/grammar.rs
index 7474713a..9d63a2be 100644
--- a/helix-loader/src/grammar.rs
+++ b/helix-loader/src/grammar.rs
@@ -92,7 +92,7 @@ pub fn build_grammars() -> Result<()> {
 // merged. The `grammar_selection` key of the config is then used to filter
 // down all grammars into a subset of the user's choosing.
 fn get_grammar_configs() -> Result<Vec<GrammarConfiguration>> {
-    let config: Configuration = crate::user_lang_config()
+    let config: Configuration = crate::config::user_lang_config()
         .context("Could not parse languages.toml")?
         .try_into()?;
 
diff --git a/helix-loader/src/lib.rs b/helix-loader/src/lib.rs
index a2c4d96f..de2951f8 100644
--- a/helix-loader/src/lib.rs
+++ b/helix-loader/src/lib.rs
@@ -1,3 +1,4 @@
+pub mod config;
 pub mod grammar;
 
 use etcetera::base_strategy::{choose_base_strategy, BaseStrategy};
@@ -36,6 +37,15 @@ pub fn config_dir() -> std::path::PathBuf {
     path
 }
 
+pub fn local_config_dirs() -> Vec<std::path::PathBuf> {
+    let directories = find_root_impl(None, &[".helix".to_string()])
+        .into_iter()
+        .map(|path| path.join(".helix"))
+        .collect();
+    log::debug!("Located configuration folders: {:?}", directories);
+    directories
+}
+
 pub fn cache_dir() -> std::path::PathBuf {
     // TODO: allow env var override
     let strategy = choose_base_strategy().expect("Unable to find the config directory!");
@@ -56,25 +66,36 @@ pub fn log_file() -> std::path::PathBuf {
     cache_dir().join("helix.log")
 }
 
-/// Default bultin-in languages.toml.
-pub fn default_lang_config() -> toml::Value {
-    toml::from_slice(include_bytes!("../../languages.toml"))
-        .expect("Could not parse bultin-in languages.toml to valid toml")
-}
-
-/// User configured languages.toml file, merged with the default config.
-pub fn user_lang_config() -> Result<toml::Value, toml::de::Error> {
-    let def_lang_conf = default_lang_config();
-    let data = std::fs::read(crate::config_dir().join("languages.toml"));
-    let user_lang_conf = match data {
-        Ok(raw) => {
-            let value = toml::from_slice(&raw)?;
-            merge_toml_values(def_lang_conf, value)
+pub fn find_root_impl(root: Option<&str>, root_markers: &[String]) -> Vec<std::path::PathBuf> {
+    let current_dir = std::env::current_dir().expect("unable to determine current directory");
+    let mut directories = Vec::new();
+
+    let root = match root {
+        Some(root) => {
+            let root = std::path::Path::new(root);
+            if root.is_absolute() {
+                root.to_path_buf()
+            } else {
+                current_dir.join(root)
+            }
         }
-        Err(_) => def_lang_conf,
+        None => current_dir,
     };
 
-    Ok(user_lang_conf)
+    for ancestor in root.ancestors() {
+        // don't go higher than repo
+        if ancestor.join(".git").is_dir() {
+            // Use workspace if detected from marker
+            directories.push(ancestor.to_path_buf());
+            break;
+        } else if root_markers
+            .iter()
+            .any(|marker| ancestor.join(marker).exists())
+        {
+            directories.push(ancestor.to_path_buf());
+        }
+    }
+    directories
 }
 
 // right overrides left