fix(extraction): a Go method carries the exportedness of its name

CHANGELOG.md

@@ -201,6 +201,8 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 #### Symbols, tests and the viewer
 
+- **Go methods now record whether they are exported.** A method on a Go type (`func (w *writer) Close()`) was always indexed as unexported, whatever the case of its name; only plain functions carried the flag. Both the native kernel and the WebAssembly path now apply Go's rule — an uppercase first letter — to methods too, so a tool asking "can another package call this?" gets the right answer. Re-index after upgrading.
+
 - **Files under an `e2e/` directory count as tests.** Their calls no longer appear as production callers in Steps, dead-code and test badges.
 
 - **Production code under a `samples` or `examples` package path is no longer treated as test code.** A Kotlin or Java project whose package path runs through `com/google/samples/…` (Now in Android, for one) had nearly every file counted as a fixture, so the Map opened on `build-logic`, the entry points hid the app, and dead-code and test badges were wrong. Only the project layout above a `src/` folder decides now; the package path below it never does.

__tests__/extraction.test.ts

@@ -11671,6 +11671,29 @@ describe('C/C++ kernel-port preParse blanks (R7a)', () => {
     expect(blankLoneMacroLines(bare)).toBe(bare);
   });
 
+  it('Go: a method carries the exportedness of its name, like a function', async () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-go-method-exported-'));
+    try {
+      fs.writeFileSync(
+        path.join(dir, 'log.go'),
+        'package log\n\ntype writer struct{}\n\nfunc (w *writer) Close() error { return nil }\n\nfunc (w *writer) flush() {}\n\nfunc Open() *writer { return &writer{} }\n\nfunc helper() {}\n'
+      );
+      const cg = await CodeGraph.init(dir, { index: true });
+      try {
+        const flag = (name: string) =>
+          cg.getNodesByKind('method').concat(cg.getNodesByKind('function')).find((n) => n.name === name)!.isExported;
+        expect(flag('Close')).toBe(true);
+        expect(flag('flush')).toBe(false);
+        expect(flag('Open')).toBe(true);
+        expect(flag('helper')).toBe(false);
+      } finally {
+        cg.close();
+      }
+    } finally {
+      fs.rmSync(dir, { recursive: true, force: true });
+    }
+  });
+
   it('blankCStatementMacroCalls blanks indented iterator macros, keeps the block', async () => {
     const { blankCStatementMacroCalls } = await import('../src/extraction/languages/c-cpp');
     const src = [

codegraph-kernel/src/go.rs

@@ -488,7 +488,10 @@ impl<'t> Walker<'t> {
             signature: self.signature_of(node),
             return_type: self.return_type_of(node),
             qualified_name: receiver_type.as_ref().map(|r| format!("{r}::{name}")),
-            ..Extra::default() // extractMethod passes no isExported
+            // methodsAreTopLevel: a Go method is a top-level declaration, so
+            // extractMethod gives it the function's exportedness (name case).
+            is_exported: Some(self.is_exported(node)),
+            ..Extra::default()
         };
         let Some(row) = self.create_node("method", &name, node, extra) else { return };
 

src/extraction/tree-sitter.ts

@@ -1799,10 +1799,20 @@ export class TreeSitterExtractor {
     const isAsync = this.extractor.isAsync?.(node);
     const isStatic = this.extractor.isStatic?.(node);
     const returnType = this.extractor.getReturnType?.(node, this.source);
+    // A method that is a top-level declaration (Go: `func (r *T) Name()`) has
+    // the same exportedness rule as a function — the name's case — and a
+    // consumer asking "can another package name this?" needs it on methods
+    // too. Class members keep the flag unset: their reachability is the
+    // class's, and the languages whose isExported walks the parent chain
+    // (JS/TS) would otherwise re-mark every member of an exported class.
+    const isExported = this.extractor.methodsAreTopLevel
+      ? this.extractor.isExported?.(node, this.source)
+      : undefined;
     const extraProps: Partial<Node> = {
       docstring,
       signature,
       visibility,
+      isExported,
       isAsync,
       isStatic,
       returnType,