fix(extraction): warn when parse errors leave no symbols (#1522) (#1799)

Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>

src/bin/codegraph.ts

@@ -378,6 +378,7 @@ type IndexResult = {
  */
 function printIndexResult(clack: typeof import('@clack/prompts'), result: IndexResult, projectPath?: string): void {
   const hasErrors = result.filesErrored > 0;
+  const parseWarnings = result.errors.filter((e) => e.code === 'parse_error' && e.severity === 'warning');
 
   // Surface non-file-level failures (e.g. lock-acquisition failure
   // when another indexer is running) before the file-count branches.
@@ -403,6 +404,10 @@ function printIndexResult(clack: typeof import('@clack/prompts'), result: IndexR
       clack.log.success(`Indexed ${formatNumber(result.filesIndexed)} files`);
     }
     clack.log.info(`${formatNumber(result.nodesCreated)} nodes, ${formatNumber(result.edgesCreated)} edges in ${formatDuration(result.durationMs)}`);
+    // Warning-only parse failures keep indexing successful, but must be visible.
+    for (const warning of parseWarnings) {
+      clack.log.warn(warning.message);
+    }
     // A PARTIAL index (files silently dropped mid-pipeline) must not pass
     // as a clean run — it's the difference between "indexed the repo" and
     // "indexed most of the repo, quietly". Only the completeness

src/extraction/tree-sitter.ts

@@ -584,6 +584,18 @@ export class TreeSitterExtractor {
 
       if (packageNodeId) this.nodeStack.pop();
       this.nodeStack.pop();
+
+      // hasError is routine for several grammars; warn only when no symbols survived.
+      const symbolCount = this.nodes.filter((n) => n.kind !== 'file').length;
+      if (this.tree?.rootNode.hasError && symbolCount === 0) {
+        this.errors.push({
+          message:
+            `${this.filePath}: parse produced no symbols (tree has errors) — ` +
+            `the file is indexed but contributes nothing to the graph`,
+          severity: 'warning',
+          code: 'parse_error',
+        });
+      }
     } catch (error) {
       const msg = error instanceof Error ? error.message : String(error);