fix(extraction): reach a Swift URL built by a constructor

Swift has no URL literal, so almost no real code passes a bare string to a
request. It writes URL(string: "https://…")! instead, and the literal then
sits two levels below the argument list: past the trailing "!", which the
grammar models as a postfix_expression, and inside the constructor's own
value_arguments.

extract_url_or_topic_arg saw only the outer node and gave up, so the URL
never reached the service-pattern table and no Route node formed. That is
the shape issue #1892 reported from a real project — reaching a bare string
argument was only the layer underneath it.

swift_unwrap_url_constructor() steps past both wrappers. It unwraps only
URL, URLComponents and URLRequest, so any other constructor keeps its own
meaning and the outer call does not borrow the inner call's string. A
non-literal argument such as URL(string: base + path) falls through to the
ordinary handling unchanged.

The value_argument unwrap added for the bare-string case is now
swift_argument_value(), because the nested argument list needs the same
step and the code was identical.

Refs #1892

Signed-off-by: Joshua Richter <jrichter5781@gmail.com>

Author: CaptainMittens

internal/cbm/extract_calls.c

@@ -2257,6 +2257,61 @@ static const char *extract_binary_concat_suffix(CBMExtractCtx *ctx, TSNode node)
 }
 
 // Try to extract URL/topic from a positional argument (string or constant).
+/* Swift names its call arguments, so each one is a value_argument that may lead
+ * with a value_argument_label — the `from:` in `data(from: url)`. Return the
+ * value itself, and leave any other node exactly as it came in. */
+static TSNode swift_argument_value(TSNode arg) {
+    if (strcmp(ts_node_type(arg), "value_argument") != 0 || ts_node_named_child_count(arg) == 0) {
+        return arg;
+    }
+    TSNode val = ts_node_named_child(arg, 0);
+    if (strcmp(ts_node_type(val), "value_argument_label") == 0 &&
+        ts_node_named_child_count(arg) > 1) {
+        val = ts_node_named_child(arg, 1);
+    }
+    return val;
+}
+
+/* Swift has no URL literal, so almost no real code passes a bare string to a
+ * request. It writes `URL(string: "https://…")!` instead, and the literal then
+ * sits two levels down: past the trailing `!`, which the grammar models as a
+ * postfix_expression, and inside the constructor's own argument list.
+ *
+ * Unwrap both so that literal is as reachable as a bare one. Only the three
+ * Foundation types that take a URL string are unwrapped — any other call keeps
+ * its own meaning, and a non-literal argument such as `URL(string: base + path)`
+ * falls through to the ordinary handling unchanged. */
+static TSNode swift_unwrap_url_constructor(CBMExtractCtx *ctx, TSNode arg) {
+    /* Step past a trailing "!" or "?". */
+    if (strcmp(ts_node_type(arg), "postfix_expression") == 0) {
+        TSNode target = ts_node_child_by_field_name(arg, TS_FIELD("target"));
+        if (!ts_node_is_null(target)) {
+            arg = target;
+        }
+    }
+    if (strcmp(ts_node_type(arg), "call_expression") != 0) {
+        return arg;
+    }
+    TSNode callee = ts_node_named_child(arg, 0);
+    if (ts_node_is_null(callee) || strcmp(ts_node_type(callee), "simple_identifier") != 0) {
+        return arg;
+    }
+    const char *name = cbm_node_text(ctx->arena, callee, ctx->source);
+    if (!name || (strcmp(name, "URL") != 0 && strcmp(name, "URLComponents") != 0 &&
+                  strcmp(name, "URLRequest") != 0)) {
+        return arg;
+    }
+    TSNode suffix = cbm_find_child_by_kind(arg, "call_suffix");
+    if (ts_node_is_null(suffix)) {
+        return arg;
+    }
+    TSNode inner = cbm_find_child_by_kind(suffix, "value_arguments");
+    if (ts_node_is_null(inner) || ts_node_named_child_count(inner) == 0) {
+        return arg;
+    }
+    return swift_argument_value(ts_node_named_child(inner, 0));
+}
+
 static const char *extract_positional_url(CBMExtractCtx *ctx, TSNode arg, const char *ak) {
     /* JS/TS template literals: `/things/${id}` normalizes to "/things/{}" so the
      * client URL joins the server route's canonical placeholder (issue #1006). */
@@ -2300,15 +2355,12 @@ static const char *extract_url_or_topic_arg(CBMExtractCtx *ctx, TSNode args) {
         }
         /* Swift wraps each argument in a value_argument that may lead with its
          * label, so `data(from: url)` would otherwise yield the label `from`
-         * rather than the value. Step past a leading value_argument_label. */
-        if (strcmp(ts_node_type(arg), "value_argument") == 0 &&
-            ts_node_named_child_count(arg) > 0) {
-            TSNode val = ts_node_named_child(arg, 0);
-            if (strcmp(ts_node_type(val), "value_argument_label") == 0 &&
-                ts_node_named_child_count(arg) > 1) {
-                val = ts_node_named_child(arg, 1);
-            }
-            arg = val;
+         * rather than the value. */
+        arg = swift_argument_value(arg);
+        /* A Swift URL is usually built rather than written bare, and the
+         * literal then sits inside that constructor. */
+        if (ctx->language == CBM_LANG_SWIFT) {
+            arg = swift_unwrap_url_constructor(ctx, arg);
         }
         const char *ak = ts_node_type(arg);
 

tests/test_extraction.c

@@ -4186,6 +4186,52 @@ TEST(swift_labeled_call_string_arg_issue1892) {
     PASS();
 }
 
+/* Swift has no URL literal, so real code builds one and force-unwraps it. The
+ * string then sits two levels below the argument list. */
+TEST(swift_nested_url_constructor_issue1892) {
+    CBMFileResult *r = extract("func fetch() { URLSession.shared.dataTask(with: URL(string: "
+                               "\"https://example.com/api/v1/widgets\")!) }\n",
+                               CBM_LANG_SWIFT, "t", "Fetch.swift");
+    ASSERT_NOT_NULL(r);
+    ASSERT_FALSE(r->has_error);
+    const CBMCall *c = find_call_by_callee(r, "URLSession.shared.dataTask");
+    ASSERT_NOT_NULL(c);
+    ASSERT_NOT_NULL(c->first_string_arg);
+    ASSERT_STR_EQ(c->first_string_arg, "https://example.com/api/v1/widgets");
+    cbm_free_result(r);
+    PASS();
+}
+
+/* Without the trailing "!" the constructor is not wrapped in a
+ * postfix_expression, so this covers the other shape. */
+TEST(swift_nested_url_no_bang_issue1892) {
+    CBMFileResult *r =
+        extract("func fetch() { client.send(to: URLRequest(url: \"/api/v1/widgets/1\")) }\n",
+                CBM_LANG_SWIFT, "t", "Send.swift");
+    ASSERT_NOT_NULL(r);
+    ASSERT_FALSE(r->has_error);
+    const CBMCall *c = find_call_by_callee(r, "client.send");
+    ASSERT_NOT_NULL(c);
+    ASSERT_NOT_NULL(c->first_string_arg);
+    ASSERT_STR_EQ(c->first_string_arg, "/api/v1/widgets/1");
+    cbm_free_result(r);
+    PASS();
+}
+
+/* A constructor that is not one of the three URL types keeps its own meaning:
+ * the outer call must not borrow the inner call's string. */
+TEST(swift_non_url_constructor_untouched_issue1892) {
+    CBMFileResult *r = extract("func f() { log.write(to: Formatter(pattern: \"%s-%d\")) }\n",
+                               CBM_LANG_SWIFT, "t", "Log.swift");
+    ASSERT_NOT_NULL(r);
+    ASSERT_FALSE(r->has_error);
+    const CBMCall *c = find_call_by_callee(r, "log.write");
+    ASSERT_NOT_NULL(c);
+    ASSERT_NULL(c->first_string_arg);
+    cbm_free_result(r);
+    PASS();
+}
+
 /* Issue #1009: URL-builder helper pattern — a function returning a URL-shaped
  * literal, consumed as client(buildPath(id)). The builder's URL is recorded in
  * the per-file constant map and resolved at the call site, for both return
@@ -7131,6 +7177,9 @@ SUITE(extraction) {
     RUN_TEST(swift_chained_call);
     RUN_TEST(swift_force_unwrap_scanner_shift);
     RUN_TEST(swift_call_string_arg_issue1892);
+    RUN_TEST(swift_nested_url_constructor_issue1892);
+    RUN_TEST(swift_nested_url_no_bang_issue1892);
+    RUN_TEST(swift_non_url_constructor_untouched_issue1892);
     RUN_TEST(swift_labeled_call_string_arg_issue1892);
     RUN_TEST(objc_interface);
     RUN_TEST(objc_implementation);

tests/test_pipeline.c

@@ -5690,6 +5690,55 @@ TEST(pipeline_native_fetch_classified_as_http_calls) {
  * no call arguments at all. Alamofire/URLSession were already in the service
  * pattern table; the URL simply never reached it. This is the Swift twin of
  * the TypeScript fetch case above. */
+/* The shape real Swift actually writes: the URL is built by a constructor and
+ * force-unwrapped, so the literal is two levels below the argument list. This
+ * is what issue #1892 reported from a real project. */
+TEST(pipeline_swift_nested_url_makes_route_issue1892) {
+    char tmp[256];
+    snprintf(tmp, sizeof(tmp), "/tmp/cbm_swiftnested_XXXXXX");
+    if (!cbm_mkdtemp(tmp)) {
+        FAIL("tmpdir");
+    }
+
+    write_temp_file(tmp, "Sources/Client.swift",
+                    "import Foundation\n"
+                    "final class Client {\n"
+                    "    func listWidgets() {\n"
+                    "        URLSession.shared.dataTask(with: "
+                    "URL(string: \"/api/v1/widgets\")!)\n"
+                    "    }\n"
+                    "}\n");
+
+    char db_path[512];
+    snprintf(db_path, sizeof(db_path), "%s/swiftnested.db", tmp);
+    cbm_pipeline_t *p = cbm_pipeline_new(tmp, db_path, CBM_MODE_FULL);
+    ASSERT_NOT_NULL(p);
+    ASSERT_EQ(cbm_pipeline_run(p), 0);
+    const char *project = cbm_pipeline_project_name(p);
+
+    cbm_store_t *s = cbm_store_open_path(db_path);
+    ASSERT_NOT_NULL(s);
+
+    ASSERT_GTE(cbm_store_count_edges_by_type(s, project, "HTTP_CALLS"), 1);
+
+    cbm_node_t *routes = NULL;
+    int route_count = 0;
+    cbm_store_find_nodes_by_label(s, project, "Route", &routes, &route_count);
+    int widget_routes = 0;
+    for (int i = 0; i < route_count; i++) {
+        if (routes[i].qualified_name && strstr(routes[i].qualified_name, "/api/v1/widgets")) {
+            widget_routes++;
+        }
+    }
+    cbm_store_free_nodes(routes, route_count);
+    ASSERT_GTE(widget_routes, 1);
+
+    cbm_store_close(s);
+    cbm_pipeline_free(p);
+    th_rmtree(tmp);
+    PASS();
+}
+
 TEST(pipeline_swift_http_call_makes_route_issue1892) {
     char tmp[256];
     snprintf(tmp, sizeof(tmp), "/tmp/cbm_swifthttp_XXXXXX");
@@ -13475,6 +13524,7 @@ SUITE(pipeline) {
     RUN_TEST(pipeline_parallel_rust_cross_only_macro_hidden_gets_synthetic_carrier);
     RUN_TEST(pipeline_arg_url_rejects_non_http_slash_arguments);
     RUN_TEST(pipeline_native_fetch_classified_as_http_calls);
+    RUN_TEST(pipeline_swift_nested_url_makes_route_issue1892);
     RUN_TEST(pipeline_swift_http_call_makes_route_issue1892);
     RUN_TEST(pipeline_native_fetch_parallel_classified_as_http_calls);
     RUN_TEST(pipeline_local_fetch_shadow_not_classified_as_http);