fix(parser): recognize Gleam dev/ directories as source roots

Modern Gleam packages have src/, test/ and dev/ module directories.
Without dev/ roots, imports from or into dev/ modules resolved into
foreign packages when module names collided. Adds dev to both the
structural and the gleam.toml-derived root derivation, with tests.

Author: oderwat

src/jcodemunch_mcp/parser/imports.py

@@ -937,14 +937,15 @@ def _gleam_source_roots(source_files) -> tuple[str, ...]:
     """Detect Gleam source roots from the indexed file set.
 
     A Gleam module path like ``webse/config_types`` is relative to a
-    package's ``src/`` or ``test/`` directory, so those directories are the
-    source roots. They are derived structurally: every path prefix of an
-    indexed ``.gleam`` file that ends in a ``src`` or ``test`` segment
-    (``cells/webse/src/webse/config.gleam`` -> ``cells/webse/src``), plus
-    ``<dir>/src`` and ``<dir>/test`` for every indexed ``gleam.toml``. The
-    two signals overlap for normal packages; the gleam.toml one also covers
-    packages whose files did not make it into the index, and the structural
-    one covers indexes that exclude toml files.
+    package's ``src/``, ``test/`` or ``dev/`` directory, so those
+    directories are the source roots. They are derived structurally: every
+    path prefix of an indexed ``.gleam`` file that ends in a ``src``,
+    ``test`` or ``dev`` segment (``cells/webse/src/webse/config.gleam`` ->
+    ``cells/webse/src``), plus ``<dir>/src``, ``<dir>/test`` and
+    ``<dir>/dev`` for every indexed ``gleam.toml``. The two signals overlap
+    for normal packages; the gleam.toml one also covers packages whose
+    files did not make it into the index, and the structural one covers
+    indexes that exclude toml files.
     """
     cache_key = source_files if isinstance(source_files, frozenset) else frozenset(source_files)
     cached = _gleam_roots_cache.get(cache_key)
@@ -956,11 +957,11 @@ def _gleam_source_roots(source_files) -> tuple[str, ...]:
         if f.endswith(".gleam"):
             parts = f.split("/")
             for i, seg in enumerate(parts[:-1]):
-                if seg in ("src", "test"):
+                if seg in ("src", "test", "dev"):
                     roots.add("/".join(parts[: i + 1]))
         elif f == "gleam.toml" or f.endswith("/gleam.toml"):
             pkg_dir = f[: -len("/gleam.toml")] if "/" in f else ""
-            for sub in ("src", "test"):
+            for sub in ("src", "test", "dev"):
                 roots.add(f"{pkg_dir}/{sub}" if pkg_dir else sub)
 
     result = tuple(sorted(roots))
@@ -1356,9 +1357,9 @@ def resolve_specifier(
 
     # Gleam module-style import: 'webse/config_types' →
     # 'cells/webse/src/webse/config_types.gleam'. Gleam module paths are
-    # slash-joined lowercase segments resolved against a package's src/ or
-    # test/ root; the target extension is always .gleam, so candidates are
-    # built directly instead of via _candidates. The importer's own package
+    # slash-joined lowercase segments resolved against a package's src/,
+    # test/ or dev/ root; the target extension is always .gleam, so candidates
+    # are built directly instead of via _candidates. The importer's own package
     # root is tried first: module paths are only unique per package, and
     # same-package imports are the common case. Stdlib and hex-dependency
     # imports (gleam/io, gleam/list) resolve to nothing — no edge is created.

tests/test_gleam_imports.py

@@ -87,6 +87,7 @@ def test_no_false_positives_from_non_import_lines(self):
     "cells/webse/src/webse/config_types.gleam",
     "cells/webse/test/webse_test.gleam",
     "cells/webse/test/support/helper.gleam",
+    "cells/webse/dev/seed_data.gleam",
     "soma/src/soma/config_yaml.gleam",
     "cx/src/cx/cluster_config_yaml.gleam",
     "cells/webse/gleam.toml",
@@ -101,6 +102,7 @@ def test_structural_roots_from_gleam_files(self):
         assert "packages/yamlutils/src" in roots
         assert "cells/webse/src" in roots
         assert "cells/webse/test" in roots
+        assert "cells/webse/dev" in roots
         assert "soma/src" in roots
         assert "cx/src" in roots
 
@@ -109,6 +111,7 @@ def test_gleam_toml_derived_roots(self):
         roots = _gleam_source_roots(files)
         assert "cells/empty/src" in roots
         assert "cells/empty/test" in roots
+        assert "cells/empty/dev" in roots
 
     def test_root_level_package(self):
         files = frozenset({"src/app.gleam", "test/app_test.gleam", "gleam.toml"})
@@ -132,12 +135,15 @@ class TestGleamSpecifierResolution:
         # Test module importing a test-only helper module
         ("support/helper", "cells/webse/test/webse_test.gleam",
          "cells/webse/test/support/helper.gleam"),
+        # Dev module importing its package's src module
+        ("webse/config_types", "cells/webse/dev/seed_data.gleam",
+         "cells/webse/src/webse/config_types.gleam"),
         # Stdlib / hex dependency: unresolvable, no edge
         ("gleam/io", "cells/webse/src/webse/config_yaml.gleam", None),
         ("gleam/list", "soma/src/soma/config_yaml.gleam", None),
     ], ids=[
         "cross_package", "same_package", "test_to_src", "test_helper",
-        "stdlib_io", "stdlib_list",
+        "dev_to_src", "stdlib_io", "stdlib_list",
     ])
     def test_resolution(self, specifier, importer, expected):
         result = resolve_specifier(specifier, importer, set(WEVE_STYLE_FILES))