Test external modules explicitly in CI (#8507)

This setup is much simpler than calling Bazel from within Bazel
and making sure files and flags are set up correctly.

Co-authored-by: Derek Bailey <derekbailey@google.com>

tests/BUILD.bazel

@@ -1,7 +1,6 @@
 load("@aspect_bazel_lib//lib:copy_to_bin.bzl", "copy_to_bin")
 load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 load("//:build_defs.bzl", "DEFAULT_FLATC_ARGS", "flatbuffer_cc_library")
-load(":defs.bzl", "flatbuffers_as_external_repo_test")
 
 package(default_visibility = ["//visibility:private"])
 
@@ -269,8 +268,3 @@ flatbuffer_cc_library(
     name = "alignment_test_cc_fbs",
     srcs = ["alignment_test.fbs"],
 )
-
-flatbuffers_as_external_repo_test(
-    name = "bazel_repository_test",
-    directory = "bazel_repository_test_dir",
-)

tests/bazel_repository_test_template.sh

@@ -1,29 +0,0 @@
-#!/bin/bash
-
-# This test makes sure that a separate repository can import the flatbuffers
-# repository and use it in their code.
-
-# --- begin runfiles.bash initialization v3 ---
-# Copy-pasted from the Bazel Bash runfiles library v3.
-set -uo pipefail; set +e; f=bazel_tools/tools/bash/runfiles/runfiles.bash
-source "${RUNFILES_DIR:-/dev/null}/$f" 2>/dev/null || \
-  source "$(grep -sm1 "^$f " "${RUNFILES_MANIFEST_FILE:-/dev/null}" | cut -f2- -d' ')" 2>/dev/null || \
-  source "$0.runfiles/$f" 2>/dev/null || \
-  source "$(grep -sm1 "^$f " "$0.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/null || \
-  source "$(grep -sm1 "^$f " "$0.exe.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/null || \
-  { echo>&2 "ERROR: cannot find $f"; exit 1; }; f=; set -e
-# --- end runfiles.bash initialization v3 ---
-
-BAZEL_BIN="$(rlocation {{BAZEL_PATH}})"
-readonly BAZEL_BIN
-
-if [[ ! -x "${BAZEL_BIN}" ]]; then
-    echo "Failed to find the bazel binary." >&2
-    exit 1
-fi
-
-export PATH="$(dirname "${BAZEL_BIN}"):${PATH}"
-
-cd {{REPOSITORY_DIR}}
-
-bazel test //...

tests/defs.bzl

@@ -1,74 +0,0 @@
-"""Helper macros and rules for tests."""
-
-load("@bazel_binaries//:defs.bzl", "bazel_binaries")
-load("@bazel_skylib//lib:paths.bzl", "paths")
-load("@bazel_skylib//rules:expand_template.bzl", "expand_template")
-
-def repo_name(label):
-    if hasattr(label, "repo_name"):  # Added in Bazel 7.1
-        return label.repo_name
-    else:
-        return "build_bazel_bazel_6_3_2"
-
-def rlocationpath(label):
-    """Returns the rlocationpath for a label
-
-    Args:
-        label (Label): The label to determine the rlocationpath for
-
-    Returns:
-        str: The rlocationpath for label
-    """
-    path = ""
-    if repo_name(label):
-        path += repo_name(label) + "/"
-    if label.package:
-        path += label.package + "/"
-    path += label.name
-    return path
-
-def flatbuffers_as_external_repo_test(name, directory):
-    """Run all tests in a bazel workspace that imports flatbuffers as an external repository.
-
-    Args:
-        name: The name of the test target.
-        directory: The directory in which the bazel workspace is located. This is the directory
-            that imports flatbuffers as an external repository.
-    """
-    bazel_binary_label = Label(bazel_binaries.label(bazel_binaries.versions.current))
-    expand_template(
-        name = name + "__template_expansion",
-        out = name + ".sh",
-        substitutions = {
-            "{{REPOSITORY_DIR}}": paths.join(native.package_name(), directory),
-            "{{BAZEL_PATH}}": rlocationpath(bazel_binary_label),
-        },
-        template = "//tests:bazel_repository_test_template.sh",
-    )
-
-    native.sh_test(
-        name = name,
-        srcs = [":%s.sh" % name],
-        data = [
-            "//:distribution",
-            bazel_binary_label,
-        ] + native.glob(
-            [
-                directory + "/**/*",
-            ],
-            exclude = [
-                directory + "/bazel-*/**",
-            ],
-        ),
-        tags = [
-            # Since we have bazel downloading external repositories inside this
-            # test, we need to give it access to the internet.
-            "requires-network",
-        ],
-        # We only have x86_64 Linux bazel exposed so restrict the test to that.
-        target_compatible_with = [
-            "@platforms//cpu:x86_64",
-            "@platforms//os:linux",
-        ],
-        deps = ["@bazel_tools//tools/bash/runfiles"],
-    )

tests/ts/BUILD.bazel

@@ -1,7 +1,6 @@
 load("@aspect_rules_js//js:defs.bzl", "js_test")
 load("@aspect_rules_js//npm:defs.bzl", "npm_link_package")
 load("//:typescript.bzl", "flatbuffer_ts_library")
-load("//tests:defs.bzl", "flatbuffers_as_external_repo_test")
 
 package(default_visibility = ["//visibility:private"])
 
@@ -61,8 +60,3 @@ TEST_COMPLEX_ARRAYS_DATA = glob([
     #("JavaScriptFlexBuffersTest", TBD_DATA)
     ("JavaScriptComplexArraysTest", TEST_COMPLEX_ARRAYS_DATA),
 )]
-
-flatbuffers_as_external_repo_test(
-    name = "bazel_repository_test",
-    directory = "bazel_repository_test_dir",
-)