Change setting name and add comment explaining the consequences

languages/tree-sitter-stack-graphs-typescript/rust/lib.rs

@@ -57,6 +57,6 @@ pub fn try_language_configuration(
     lc.special_files
         .add("tsconfig.json".to_string(), TsConfigAnalyzer {})
         .add("package.json".to_string(), NpmPackageAnalyzer {});
-    lc.has_similar_paths = false;
+    lc.no_similar_paths_in_file = true;
     Ok(lc)
 }

stack-graphs/src/stitching.rs

@@ -809,6 +809,7 @@ impl<H> ForwardPartialPathStitcher<H> {
             initial_paths: next_iteration.0.len(),
             next_iteration,
             appended_paths,
+            // By default, all paths are checked for similarity
             similar_path_detector: Some(SimilarPathDetector::new()),
             // By default, all nodes are checked for cycles and (if enabled) similarity
             check_only_join_nodes: false,

tree-sitter-stack-graphs/src/cli/index.rs

@@ -281,7 +281,7 @@ impl<'a> Indexer<'a> {
             Err(e) => return Err(IndexError::LoadError(e)),
         };
         let stitcher_config =
-            StitcherConfig::default().with_detect_similar_paths(lcs.has_similar_paths());
+            StitcherConfig::default().with_detect_similar_paths(!lcs.no_similar_paths_in_file());
 
         let source = file_reader.get(source_path)?;
         let tag = sha1(source);

tree-sitter-stack-graphs/src/cli/test.rs

@@ -326,7 +326,7 @@ impl TestArgs {
             }
         }
         let stitcher_config =
-            StitcherConfig::default().with_detect_similar_paths(lc.has_similar_paths);
+            StitcherConfig::default().with_detect_similar_paths(!lc.no_similar_paths_in_file);
         let mut partials = PartialPaths::new();
         let mut db = Database::new();
         for file in test.graph.iter_files() {

tree-sitter-stack-graphs/src/loader.rs

@@ -44,7 +44,11 @@ pub struct LanguageConfiguration {
     pub sgl: StackGraphLanguage,
     pub builtins: StackGraph,
     pub special_files: FileAnalyzers,
-    pub has_similar_paths: bool,
+    /// Can be set to true if the stack graph rules ensure that there can be no similar
+    /// paths in a file, in which case it is safe to turn of similar path detection. If
+    /// incorrectly set to true, performance of path finding suffers from exponential
+    /// blow up.
+    pub no_similar_paths_in_file: bool,
 }
 
 impl LanguageConfiguration {
@@ -98,7 +102,7 @@ impl LanguageConfiguration {
             sgl,
             builtins,
             special_files: FileAnalyzers::new(),
-            has_similar_paths: true,
+            no_similar_paths_in_file: false,
         })
     }
 
@@ -369,18 +373,15 @@ impl FileLanguageConfigurations<'_> {
         self.primary.is_some() || !self.secondary.is_empty()
     }
 
-    pub fn has_similar_paths(&self) -> bool {
+    pub fn no_similar_paths_in_file(&self) -> bool {
+        let mut no_similar_paths_in_file = true;
         if let Some(lc) = &self.primary {
-            if lc.has_similar_paths {
-                return true;
-            }
+            no_similar_paths_in_file &= lc.no_similar_paths_in_file;
         }
         for (lc, _) in &self.secondary {
-            if lc.has_similar_paths {
-                return true;
-            }
+            no_similar_paths_in_file &= lc.no_similar_paths_in_file;
         }
-        return false;
+        return no_similar_paths_in_file;
     }
 }
 
@@ -593,7 +594,7 @@ impl PathLoader {
                     builtins,
                     special_files: FileAnalyzers::new(),
                     // always detect similar paths, we don't know the language configuration when loading from the file system
-                    has_similar_paths: true,
+                    no_similar_paths_in_file: false,
                 };
                 self.cache.push((language.language, lc));
 

tree-sitter-stack-graphs/tests/it/loader.rs

@@ -35,7 +35,7 @@ fn can_load_from_provided_language_configuration() {
         sgl,
         builtins: StackGraph::new(),
         special_files: FileAnalyzers::new(),
-        has_similar_paths: true,
+        no_similar_paths_in_file: false,
     };
     let mut loader =
         Loader::from_language_configurations(vec![lc], None).expect("Expected loader to succeed");