Fix reflection.fbs import path (#8499)

We need to copy the .fbs files into the package used for .bfbs files.
This is necessary as flatc doesn't provide support to specify the full
output file name for an .fbs file in a different folder.
I tried OUTPUT_FILE env var but this doesn't seem to be honored by
flatc.

build_defs.bzl

@@ -142,6 +142,8 @@ def flatbuffer_library_public(
         reflection_genrule_cmd = " ".join([
             "SRCS=($(SRCS));",
             "for f in $${SRCS[@]:0:%s}; do" % len(srcs),
+            # Move the .fbs file into the current package if it is not there already
+            'if [[ $$(dirname $$f) != "{0}" ]]; then s="$$f"; f="{0}/$$(basename "$$f")"; mkdir -p "{0}"; mv "$$s" "$$f"; fi;'.format(native.package_relative_label(":invalid").package),
             "$(location %s)" % (TRUE_FLATC_PATH),
             "-b --schema",
             " ".join(flatc_args),
@@ -152,9 +154,10 @@ def flatbuffer_library_public(
             "done",
         ])
         reflection_outs = [
-            (out_prefix + "%s.bfbs") % (s.replace(".fbs", "").split("/")[-1])
+            (out_prefix + "%s.bfbs") % (native.package_relative_label(s).name.removesuffix(".fbs"))
             for s in srcs
         ]
+
         native.genrule(
             name = "%s_srcs" % reflection_name,
             srcs = srcs + includes,

reflection/BUILD.bazel

@@ -7,6 +7,12 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 
+# flatbuffer_ts_library() only supports .fbs file but not filegroups
+exports_files(
+    srcs = ["reflection.fbs"],
+    visibility = ["//visibility:public"],
+)
+
 filegroup(
     name = "reflection_fbs_schema",
     srcs = ["reflection.fbs"],

reflection/ts/BUILD.bazel

@@ -1,15 +1,8 @@
 load("//:typescript.bzl", "flatbuffer_ts_library")
 
-genrule(
-    name = "copy_schema_to_folder",
-    srcs = ["//reflection:reflection_fbs_schema"],
-    outs = ["reflection.fbs"],
-    cmd = "cp $< $@",
-)
-
 flatbuffer_ts_library(
     name = "reflection_ts_fbs",
-    srcs = [":reflection.fbs"],
+    srcs = ["//reflection:reflection.fbs"],
     gen_reflections = True,
     visibility = ["//visibility:public"],
 )

tests/ts/BUILD.bazel

@@ -18,6 +18,7 @@ flatbuffer_ts_library(
     name = "typescript_ts_fbs",
     srcs = ["typescript_keywords.fbs"],
     deps = [
+        "//reflection/ts:reflection_ts_fbs",
         "//tests/ts/test_dir:include_ts_fbs",
         "//tests/ts/test_dir:typescript_transitive_ts_fbs",
     ],

typescript.bzl

@@ -47,7 +47,7 @@ def flatbuffer_ts_library(
         reflection binaries for the schemas.
     """
     srcs_lib = "%s_srcs" % (name)
-    out_base = [s.replace(".fbs", "").split("/")[-1].split(":")[-1] for s in srcs]
+    out_base = [native.package_relative_label(s).name.removesuffix(".fbs") for s in srcs]
 
     if len(srcs) != 1:
         fail("flatbuffer_ts_library only supports one .fbs file per target currently.")