From eb50569bed508b71e1f18d2f2f516fec050f441b Mon Sep 17 00:00:00 2001
From: Martin Vogel <martin.vogel@datadice.io>
Date: Sun, 31 May 2026 23:45:35 +0200
Subject: [PATCH] fix(extract): capture arrow methods returned from JS/TS
 factory functions

walk_defs stopped descending into a function body once the function itself
was extracted, so arrow methods of an object literal returned from a factory
(the Zustand actions-slice pattern) were never visited. Let JS/TS/TSX descend
into function bodies (as Wolfram already did) and resolve an arrow's name from
a 'pair' parent's key, so { addItem: (...) => {...} } is captured as a Function.
Anonymous nested arrows have no resolvable name and are skipped, so no noise.

Closes #341
---
 internal/cbm/extract_defs.c | 32 ++++++++++++++++++++++++++++----
 tests/test_extraction.c     | 22 ++++++++++++++++++++++
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/internal/cbm/extract_defs.c b/internal/cbm/extract_defs.c
index 9884b4afe..7a877ea1b 100644
--- a/internal/cbm/extract_defs.c
+++ b/internal/cbm/extract_defs.c
@@ -546,16 +546,26 @@ static TSNode find_cpp_template_inner_node(TSNode node, CBMLanguage lang) {
     return null_node;
 }
 
-// Try arrow_function name via parent variable_declarator (top-level resolution).
+// Try arrow_function name via parent variable_declarator (top-level resolution)
+// or object-literal property (`pair` key) — the latter covers factory functions
+// that return an object of arrow methods (the Zustand actions-slice pattern, #341).
 static TSNode resolve_toplevel_arrow_name(TSNode node, const char *kind) {
     if (strcmp(kind, "arrow_function") != 0) {
         TSNode null_node = {0};
         return null_node;
     }
     TSNode parent = ts_node_parent(node);
-    if (!ts_node_is_null(parent) && strcmp(ts_node_type(parent), "variable_declarator") == 0) {
+    if (ts_node_is_null(parent)) {
+        TSNode null_node = {0};
+        return null_node;
+    }
+    const char *pk = ts_node_type(parent);
+    if (strcmp(pk, "variable_declarator") == 0) {
         return ts_node_child_by_field_name(parent, TS_FIELD("name"));
     }
+    if (strcmp(pk, "pair") == 0) {
+        return ts_node_child_by_field_name(parent, TS_FIELD("key"));
+    }
     TSNode null_node = {0};
     return null_node;
 }
@@ -2113,7 +2123,9 @@ static TSNode resolve_dart_method_name(TSNode child, const char *ck) {
     return null_node;
 }
 
-// Arrow function: name on parent variable_declarator/field_definition.
+// Arrow function: name on parent variable_declarator/field_definition, or the
+// key of an object-literal property — the Zustand "actions returned from a
+// factory" pattern, `{ addItem: (...) => {...} }` (#341).
 static TSNode resolve_arrow_func_name(TSNode child) {
     TSNode parent = ts_node_parent(child);
     if (!ts_node_is_null(parent)) {
@@ -2124,6 +2136,10 @@ static TSNode resolve_arrow_func_name(TSNode child) {
         if (strcmp(pk, "public_field_definition") == 0 || strcmp(pk, "variable_declarator") == 0) {
             return ts_node_child_by_field_name(parent, TS_FIELD("name"));
         }
+        if (strcmp(pk, "pair") == 0) {
+            // Object-literal property `key: () => {...}` → name is the key.
+            return ts_node_child_by_field_name(parent, TS_FIELD("key"));
+        }
     }
     TSNode null_node = {0};
     return null_node;
@@ -3581,7 +3597,15 @@ static void walk_defs(CBMExtractCtx *ctx, TSNode root, const CBMLangSpec *spec,
         if (cbm_kind_in_set(node, spec->function_node_types)) {
             if (!is_template_class_node(node, ctx->language)) {
                 extract_func_def(ctx, node, spec);
-                if (ctx->language != CBM_LANG_WOLFRAM) {
+                // Most languages stop here. JS/TS (and Wolfram) descend into the
+                // function body so NESTED named definitions are also captured —
+                // e.g. arrow methods of an object literal returned from a factory
+                // (the Zustand actions-slice pattern, #341). Anonymous nested
+                // arrows have no resolvable name and are skipped.
+                bool descend_into_func =
+                    (ctx->language == CBM_LANG_WOLFRAM || ctx->language == CBM_LANG_TYPESCRIPT ||
+                     ctx->language == CBM_LANG_JAVASCRIPT || ctx->language == CBM_LANG_TSX);
+                if (!descend_into_func) {
                     continue;
                 }
             }
diff --git a/tests/test_extraction.c b/tests/test_extraction.c
index fd1107b3d..4a3a65808 100644
--- a/tests/test_extraction.c
+++ b/tests/test_extraction.c
@@ -99,6 +99,27 @@ TEST(extract_r_dollar_call_issue219) {
     PASS();
 }
 
+/* --- TS: object-literal arrow methods from a factory (Zustand, #341) --- */
+TEST(extract_ts_factory_object_methods_issue341) {
+    CBMFileResult *r = extract("export function createItemActions(set, get) {\n"
+                               "  return {\n"
+                               "    addItem: (type, id) => { return 1; },\n"
+                               "    moveItem: (id, target) => { return 2; },\n"
+                               "    deleteItem: (id) => { return 3; },\n"
+                               "  };\n"
+                               "}\n",
+                               CBM_LANG_TYPESCRIPT, "t", "item-actions.ts");
+    ASSERT_NOT_NULL(r);
+    ASSERT_FALSE(r->has_error);
+    /* The factory itself + each returned arrow method are Function nodes. */
+    ASSERT(has_def_any(r, "createItemActions"));
+    ASSERT(has_def_any(r, "addItem"));
+    ASSERT(has_def_any(r, "moveItem"));
+    ASSERT(has_def_any(r, "deleteItem"));
+    cbm_free_result(r);
+    PASS();
+}
+
 /* --- Java --- */
 TEST(java_class) {
     CBMFileResult *r = extract(
@@ -2363,6 +2384,7 @@ SUITE(extraction) {
     /* R box-module imports + member calls */
     RUN_TEST(extract_r_box_use_imports_issue218);
     RUN_TEST(extract_r_dollar_call_issue219);
+    RUN_TEST(extract_ts_factory_object_methods_issue341);
 
     /* OOP */
     RUN_TEST(java_class);