fix(pipeline): preserve dotted TypeScript import basenames

src/pipeline/fqn.c

@@ -282,20 +282,19 @@ static char *resolve_python_relative(char *buf, size_t buf_size, const char *mod
     return strdup(buf);
 }
 
-/* Strip a trailing file extension from a segment (e.g. "helpers.ts" → "helpers").
- * Returns the new segment length. */
-static size_t strip_ext(const char *seg_start, size_t seg_len) {
-    const char *seg_end = seg_start + seg_len;
-    const char *dot = NULL;
-    for (const char *d = seg_end - FQN_SEP_LEN; d >= seg_start; d--) {
-        if (*d == '.') {
-            dot = d;
-            break;
+/* Strip an explicit JS/TS module file extension while preserving dots that are
+ * part of an extensionless basename (e.g. "featureX.engine"). */
+static size_t strip_js_module_ext(const char *seg_start, size_t seg_len) {
+    static const char *const extensions[] = {
+        ".js", ".jsx", ".mjs", ".cjs", ".ts", ".tsx", ".mts", ".cts", ".json",
+    };
+    for (size_t i = 0; i < sizeof(extensions) / sizeof(extensions[0]); i++) {
+        size_t ext_len = strlen(extensions[i]);
+        if (seg_len > ext_len &&
+            memcmp(seg_start + seg_len - ext_len, extensions[i], ext_len) == 0) {
+            return seg_len - ext_len;
         }
     }
-    if (dot && dot > seg_start) {
-        return (size_t)(dot - seg_start);
-    }
     return seg_len;
 }
 
@@ -322,7 +321,7 @@ static char *resolve_js_relative(char *buf, size_t buf_size, const char *module_
             continue;
         }
         if (*p == '\0') {
-            seg_len = strip_ext(seg_start, seg_len);
+            seg_len = strip_js_module_ext(seg_start, seg_len);
         }
         if (seg_len > 0 && !path_append_segment(buf, buf_size, seg_start, seg_len)) {
             return NULL;

src/pipeline/pass_pkgmap.c

@@ -1397,7 +1397,11 @@ char *cbm_pipeline_resolve_module(const cbm_pipeline_ctx_t *ctx, const char *sou
     /* 1. Try relative import resolution (existing logic) */
     char *resolved = cbm_pipeline_resolve_relative_import(source_rel, module_path);
     if (resolved) {
-        char *qn = cbm_pipeline_fqn_module(ctx->project_name, resolved);
+        /* The relative resolver has already removed an explicit JS/TS file
+         * extension.  Treat the remaining path as a module path verbatim so a
+         * dotted extensionless basename such as `featureX.engine` is not
+         * stripped a second time by cbm_pipeline_fqn_module. */
+        char *qn = cbm_pipeline_fqn_folder(ctx->project_name, resolved);
         free(resolved);
         return qn;
     }

tests/test_edge_imports.c

@@ -365,6 +365,96 @@ TEST(ei_typescript_named_relative_import) {
     PASS();
 }
 
+/* #1682: extensionless dotted basenames are part of the module name.  The
+ * resolver used to strip `.engine`, miss the module, and bind both imports to
+ * the same-named fixture Function in the sibling spec file. */
+TEST(ei_typescript_dotted_relative_import_targets_source_module_issue1682) {
+    static const char *engine_path = "packages/api/src/modules/featureX/featureX.engine.ts";
+    static const char *consumer_path = "packages/api/src/modules/consumer/consumer.service.ts";
+    static const EILangFile f[] = {
+        {"packages/api/src/modules/featureX/featureX.engine.ts",
+         "export interface SomeType { id: string; qty: number; }\n"
+         "export interface Evaluation { rateByItem: Record<string, number>; }\n"
+         "export function helperB(configs: SomeType[], lines: SomeType[]): Evaluation {\n"
+         "  return { rateByItem: { [lines[0].id]: lines[0].qty + configs.length } };\n"
+         "}\n"},
+        {"packages/api/src/modules/featureX/featureX.service.ts",
+         "import { SomeType, Evaluation, helperB } from './featureX.engine';\n"
+         "export class FeatureXService {\n"
+         "  evaluate(configs: SomeType[], lines: SomeType[]): Evaluation {\n"
+         "    return helperB(configs, lines);\n"
+         "  }\n"
+         "}\n"},
+        {"packages/api/src/modules/featureX/featureX.service.spec.ts",
+         "import { SomeType, helperB } from './featureX.engine';\n"
+         "function featureX(overrides: Partial<SomeType>): SomeType {\n"
+         "  return { id: 'x', qty: 1, ...overrides };\n"
+         "}\n"
+         "export function exerciseFixture(): number {\n"
+         "  return helperB([featureX({})], [featureX({ qty: 2 })]).rateByItem.x;\n"
+         "}\n"},
+        {"packages/api/src/modules/consumer/consumer.service.ts",
+         "import { helperB, type SomeType } from '../featureX/featureX.engine';\n"
+         "export class ConsumerService {\n"
+         "  callerMethod(items: SomeType[]): number {\n"
+         "    return helperB(items, [{ id: 'p1', qty: 1 }]).rateByItem.p1;\n"
+         "  }\n"
+         "}\n"},
+        {"packages/mobile/src/api.ts",
+         "export function helperB(token: string): Promise<unknown> {\n"
+         "  return fetch('/api/x', { method: 'POST', body: token });\n"
+         "}\n"},
+    };
+
+    EILangProj lp;
+    cbm_store_t *store = ei_index_files(&lp, f, (int)(sizeof(f) / sizeof(f[0])));
+    ASSERT_NOT_NULL(store);
+
+    int64_t consumer_id = ei_node_id_for_file_label(store, lp.project, consumer_path, "File");
+    ASSERT_GT(consumer_id, 0);
+
+    cbm_edge_t *edges = NULL;
+    int edge_count = 0;
+    ASSERT_EQ(
+        cbm_store_find_edges_by_source_type(store, consumer_id, "IMPORTS", &edges, &edge_count),
+        CBM_STORE_OK);
+
+    bool saw_helper = false;
+    bool saw_type = false;
+    bool helper_target_ok = false;
+    bool type_target_ok = false;
+    for (int i = 0; i < edge_count; i++) {
+        const char *props = edges[i].properties_json ? edges[i].properties_json : "";
+        bool is_helper = strstr(props, "\"local_name\":\"helperB\"") != NULL;
+        bool is_type = strstr(props, "\"local_name\":\"SomeType\"") != NULL;
+        if (!is_helper && !is_type) {
+            continue;
+        }
+
+        cbm_node_t *target = (cbm_node_t *)calloc(1, sizeof(cbm_node_t));
+        ASSERT_NOT_NULL(target);
+        ASSERT_EQ(cbm_store_find_node_by_id(store, edges[i].target_id, target), CBM_STORE_OK);
+        bool target_ok = target->file_path && strcmp(target->file_path, engine_path) == 0;
+        if (is_helper) {
+            saw_helper = true;
+            helper_target_ok = target_ok;
+        }
+        if (is_type) {
+            saw_type = true;
+            type_target_ok = target_ok;
+        }
+        cbm_store_free_nodes(target, 1);
+    }
+    cbm_store_free_edges(edges, edge_count);
+    ei_cleanup(&lp, store);
+
+    ASSERT_TRUE(saw_helper);
+    ASSERT_TRUE(saw_type);
+    ASSERT_TRUE(helper_target_ok);
+    ASSERT_TRUE(type_target_ok);
+    PASS();
+}
+
 /* TypeScript: default import `import helper from './util'`. */
 TEST(ei_typescript_default_import) {
     static const EILangFile f[] = {
@@ -1063,6 +1153,7 @@ SUITE(edge_imports) {
 
     /* ── GREEN GUARDS — TypeScript (must stay passing) ── */
     RUN_TEST(ei_typescript_named_relative_import);
+    RUN_TEST(ei_typescript_dotted_relative_import_targets_source_module_issue1682);
     RUN_TEST(ei_typescript_default_import);
     RUN_TEST(ei_typescript_namespace_import);
     RUN_TEST(ei_typescript_aliased_import);

tests/test_fqn.c

@@ -84,6 +84,21 @@ TEST(fqn_module_qn_still_strips_extension) {
     PASS();
 }
 
+TEST(fqn_relative_js_import_preserves_dotted_basename_issue1682) {
+    ASSERT_FQN(
+        cbm_pipeline_resolve_relative_import(
+            "packages/api/src/modules/consumer/consumer.service.ts", "../featureX/featureX.engine"),
+        "packages/api/src/modules/featureX/featureX.engine");
+    ASSERT_FQN(
+        cbm_pipeline_resolve_relative_import("packages/api/src/modules/moduleA/moduleA.service.ts",
+                                             "../moduleQ/moduleQ.service"),
+        "packages/api/src/modules/moduleQ/moduleQ.service");
+    ASSERT_FQN(cbm_pipeline_resolve_relative_import(
+                   "packages/api/src/modules/moduleA/moduleA.service.ts", "./create-thing.dto"),
+               "packages/api/src/modules/moduleA/create-thing.dto");
+    PASS();
+}
+
 TEST(fqn_compute_basic_rs) {
     ASSERT_FQN(cbm_pipeline_fqn_compute("proj", "lib.rs", "new"), "proj.lib.new");
     PASS();
@@ -665,6 +680,7 @@ SUITE(fqn) {
     RUN_TEST(fqn_file_qn_preserves_dotfile_variants_issue1077);
     RUN_TEST(fqn_file_qn_distinguishes_same_stem_header_source_issue964);
     RUN_TEST(fqn_module_qn_still_strips_extension);
+    RUN_TEST(fqn_relative_js_import_preserves_dotted_basename_issue1682);
     RUN_TEST(fqn_compute_basic_rs);
     RUN_TEST(fqn_compute_file_sibling_distinct);
     RUN_TEST(fqn_compute_symbol_still_strips);