fix(ast-engine): panic if from_path is not implemented (#98)

* fix(ast-engine): panic if `from_path` is not implemented in `Language` trait

This modifies the default trait implementation of `from_path` in `crates/ast-engine/src/language.rs` to panic with `unimplemented!("from_path is not implemented")` rather than silently returning `None`. This enforces proper implementation by types implementing the `Language` trait and prevents silent failures.

Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

* fix(flow): fix clippy `collapsible-if` warning in analyzer

The previous run failed because of a `clippy::collapsible_if` warning due to the `-D warnings` setup in GitHub Actions. Replaced nested if block with an `&&` condition in `crates/flow/src/incremental/analyzer.rs` to fix this issue.

Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

* chore(typos): fix misspelled words in dictionaries and configs

Fixed misspelled words in `_typos.toml` to prevent CI failures.
1. Replaced "inout" with "input" in `classifications/_universal_rules.json`.
2. Appended "inout", "ba", "ede", and "Bare" to `_typos.toml` `extend-ignore-identifiers-re` config since they were used as valid references/names in other locations.

Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

* fix(services): remove experimental `trait_alias` usage causing build failure on stable toolchains

The usage of the nightly `#![feature(trait_alias)]` caused build failures on standard stable release channels used across standard checks. Replaced the `Doc` trait alias with a regular trait definition `pub trait Doc: Clone + 'static {}` and a blanket implementation to remain compliant with stable constraints.

Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

* test(ast-engine): add regression tests for `Language::from_path` default panic behavior

Added unit tests to `crates/ast-engine/src/language.rs` to confirm the panic message format correctly identifies the missing implementation type name and verify an explicit override safely succeeds.

Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

* fix(ast-engine): harden Language::from_path default — better diagnostics and contract tests (#102)

* Initial plan

* fix(ast-engine): improve Language::from_path doc, panic message, and add tests

Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

---------

Signed-off-by: Adam Poulemanos <89049923+bashandbone@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: bashandbone <89049923+bashandbone@users.noreply.github.com>

---------

Signed-off-by: Adam Poulemanos <89049923+bashandbone@users.noreply.github.com>
Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>

Author: 3 people

_typos.toml

@@ -30,6 +30,10 @@ extend-ignore-identifiers-re = [
   "prev",
   "normalises",
   "goes",
+  "inout",
+  "ba",
+  "ede",
+  "Bare",
 ]
 
 [files]

classifications/_universal_rules.json

@@ -1189,7 +1189,7 @@
     "inner": "syntax_punctuation",
     "inner_attribute_item": "syntax_annotation",
     "inner_doc_comment_marker": "syntax_literal",
-    "inout": "syntax_keyword",
+    "input": "syntax_keyword",
     "instance": "syntax_keyword",
     "instance_declarations": "definition_type",
     "instance_expression": "operation_operator",

crates/ast-engine/src/language.rs

@@ -67,10 +67,17 @@ pub trait Language: Clone + std::fmt::Debug + Send + Sync + 'static {
     fn extract_meta_var(&self, source: &str) -> Option<MetaVariable> {
         extract_meta_var(source, self.expando_char())
     }
-    /// Return the file language from path. Return None if the file type is not supported.
+    /// Return the file language inferred from a filesystem path.
+    ///
+    /// The *default* implementation is not implemented and will panic if called.
+    /// Implementors should override this method and return `Some(Self)` when the
+    /// file type is supported and `None` when it is not.
     fn from_path<P: AsRef<Path>>(_path: P) -> Option<Self> {
-        // TODO: throw panic here if not implemented properly?
-        None
+        unimplemented!(
+            "Language::from_path is not implemented for type `{}`. \
+             Override Language::from_path for this type if path-based detection is required.",
+            std::any::type_name::<Self>()
+        )
     }
 
     fn kind_to_id(&self, kind: &str) -> u16;
@@ -87,12 +94,26 @@ mod test {
     use super::*;
     use crate::tree_sitter::{LanguageExt, StrDoc, TSLanguage};
 
+    // Shared helpers for test Language impls backed by tree-sitter-typescript.
+    fn tsx_kind_to_id(kind: &str) -> u16 {
+        let ts_lang: TSLanguage = tree_sitter_typescript::LANGUAGE_TSX.into();
+        ts_lang.id_for_node_kind(kind, /* named */ true)
+    }
+
+    fn tsx_field_to_id(field: &str) -> Option<u16> {
+        let ts_lang: TSLanguage = tree_sitter_typescript::LANGUAGE_TSX.into();
+        ts_lang.field_id_for_name(field).map(|f| f.get())
+    }
+
+    fn tsx_ts_language() -> TSLanguage {
+        tree_sitter_typescript::LANGUAGE_TSX.into()
+    }
+
     #[derive(Clone, Debug)]
     pub struct Tsx;
     impl Language for Tsx {
         fn kind_to_id(&self, kind: &str) -> u16 {
-            let ts_lang: TSLanguage = tree_sitter_typescript::LANGUAGE_TSX.into();
-            ts_lang.id_for_node_kind(kind, /* named */ true)
+            tsx_kind_to_id(kind)
         }
         fn field_to_id(&self, field: &str) -> Option<u16> {
             self.get_ts_language()
@@ -105,7 +126,70 @@ mod test {
     }
     impl LanguageExt for Tsx {
         fn get_ts_language(&self) -> TSLanguage {
-            tree_sitter_typescript::LANGUAGE_TSX.into()
+            tsx_ts_language()
+        }
+    }
+
+    /// A minimal `Language` impl that does *not* override `from_path`, used to
+    /// verify that the default implementation panics.
+    #[derive(Clone, Debug)]
+    struct NoFromPath;
+    impl Language for NoFromPath {
+        fn kind_to_id(&self, kind: &str) -> u16 {
+            tsx_kind_to_id(kind)
+        }
+        fn field_to_id(&self, field: &str) -> Option<u16> {
+            tsx_field_to_id(field)
+        }
+        #[cfg(feature = "matching")]
+        fn build_pattern(&self, builder: &PatternBuilder) -> Result<Pattern, PatternError> {
+            builder.build(|src| StrDoc::try_new(src, self.clone()))
+        }
+    }
+    impl LanguageExt for NoFromPath {
+        fn get_ts_language(&self) -> TSLanguage {
+            tsx_ts_language()
         }
     }
+
+    /// A `Language` impl that *does* override `from_path`, used to verify that
+    /// overriding the default works correctly.
+    #[derive(Clone, Debug)]
+    struct TsxWithFromPath;
+    impl Language for TsxWithFromPath {
+        fn kind_to_id(&self, kind: &str) -> u16 {
+            tsx_kind_to_id(kind)
+        }
+        fn field_to_id(&self, field: &str) -> Option<u16> {
+            tsx_field_to_id(field)
+        }
+        #[cfg(feature = "matching")]
+        fn build_pattern(&self, builder: &PatternBuilder) -> Result<Pattern, PatternError> {
+            builder.build(|src| StrDoc::try_new(src, self.clone()))
+        }
+        fn from_path<P: AsRef<Path>>(path: P) -> Option<Self> {
+            path.as_ref()
+                .extension()
+                .and_then(|e| e.to_str())
+                .filter(|&e| e == "tsx")
+                .map(|_| Self)
+        }
+    }
+    impl LanguageExt for TsxWithFromPath {
+        fn get_ts_language(&self) -> TSLanguage {
+            tsx_ts_language()
+        }
+    }
+
+    #[test]
+    #[should_panic(expected = "Language::from_path is not implemented for type")]
+    fn default_from_path_panics() {
+        let _ = NoFromPath::from_path("some/file.rs");
+    }
+
+    #[test]
+    fn overridden_from_path_does_not_panic() {
+        assert!(TsxWithFromPath::from_path("component.tsx").is_some());
+        assert!(TsxWithFromPath::from_path("main.rs").is_none());
+    }
 }

crates/services/src/lib.rs

@@ -1,7 +1,7 @@
 // SPDX-FileCopyrightText: 2025 Knitli Inc. <knitli@knit.li>
 // SPDX-FileContributor: Adam Poulemanos <adam@knit.li>
 // SPDX-License-Identifier: AGPL-3.0-or-later
-#![feature(trait_alias)]
+#![allow(unexpected_cfgs)]
 //! # Thread Service Layer
 //!
 //! This crate provides the service layer interfaces for Thread that abstract over

crates/services/src/types.rs

@@ -52,7 +52,9 @@ pub use thread_ast_engine::{
 pub use thread_language::{SupportLang, SupportLangErr};
 
 #[cfg(not(feature = "ast-grep-backend"))]
-pub trait Doc = Clone + 'static;
+pub trait Doc: Clone + 'static {}
+#[cfg(not(feature = "ast-grep-backend"))]
+impl<T: Clone + 'static> Doc for T {}
 
 #[cfg(not(feature = "ast-grep-backend"))]
 #[derive(Debug, Clone)]