test: Migrate external_repo tests to bazel

.bazelignore

@@ -1,2 +1 @@
 .ci/micromamba
-test/unit/external_repository

BUILD

@@ -41,11 +41,12 @@ toolchain(
     toolchain_type = ":toolchain_type",
 )
 
-# Repository root marker, used by buildifier and pylint tests
+# Repository root marker, used by the buildifier, pylint, and external_repository tests
 exports_files(
     ["MODULE.bazel"],
     visibility = [
         "//test/buildifier:__pkg__",
         "//test/pylint:__pkg__",
+        "//test/unit/external_repository:__pkg__",
     ],
 )

test/unit/external_repository/BUILD

@@ -1,4 +1,4 @@
-# Copyright 2023 Ericsson AB
+# Copyright 2026 Ericsson AB
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,49 +13,53 @@
 # limitations under the License.
 
 load(
-    "@rules_cc//cc:defs.bzl",
-    "cc_binary",
-    "cc_library",
+    "//test/unit/external_repository:external_test.bzl",
+    "external_test",
 )
-load(
-    "@rules_codechecker//:defs.bzl",
-    "codechecker_test",
-    "compile_commands",
+
+exports_files([
+    "external_test_runner.py",
+])
+
+# Source files made available to the inner build via the test runfiles
+filegroup(
+    name = "external_test_srcs",
+    srcs = [
+        "intermediate.cpp",
+        "intermediate.h",
+        "main.cc",
+    ],
 )
 
-# This is the important bit -- not only do we have an external dependency here
-# in the form of external_lib, but is also an implementation_dep. This is a
-# tricky edge case we need to handle.
-cc_library(
-    name = "intermediate_lib",
-    srcs = ["intermediate.cpp"],
-    hdrs = ["intermediate.h"],
-    implementation_deps = ["@external_lib//:lib"],
-    visibility = ["//visibility:public"],
+external_test(
+    name = "compile_commands_isystem_test",
+    action = "build",
+    contains = [
+        "-isystem external/external_lib[~+]/include",
+        "-isystem bazel-out/k8-fastbuild/bin/external/external_lib[~+]/include",
+    ],
+    output_file = "bazel-bin/compile_commands_isystem/compile_commands.json",
+    target = ":compile_commands_isystem",
 )
 
-cc_binary(
-    name = "isystem_impl_dep",
-    srcs = ["main.cc"],
-    deps = [":intermediate_lib"],
+external_test(
+    name = "codechecker_external_deps_test",
+    target = ":codechecker_external_deps",
 )
 
-compile_commands(
-    name = "compile_commands_isystem",
-    targets = [
-        ":isystem_impl_dep",
-    ],
+external_test(
+    name = "per_file_external_deps_test",
+    target = ":per_file_external_deps",
 )
 
-codechecker_test(
-    name = "codechecker_external_deps",
-    tags = ["manual"],
-    targets = ["isystem_impl_dep"],
+external_test(
+    name = "codechecker_external_include_paths_test",
+    extra_flags = ["--features=external_include_paths"],
+    target = ":codechecker_external_deps",
 )
 
-codechecker_test(
-    name = "per_file_external_deps",
-    per_file = True,
-    tags = ["manual"],
-    targets = ["isystem_impl_dep"],
+external_test(
+    name = "per_file_external_include_paths_test",
+    extra_flags = ["--features=external_include_paths"],
+    target = ":per_file_external_deps",
 )

test/unit/external_repository/external_test.bzl

@@ -0,0 +1,102 @@
+# Copyright 2026 Ericsson AB
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Macro for external repository integration tests.
+
+Each external_test() generates a py_test that:
+    1. Creates a temporary Bazel workspace with external dependencies
+    2. Runs a bazel command inside it
+    3. Asserts on exit code and optionally on output file contents
+
+Example:
+    external_test(
+        name = "compile_commands_test",
+        target = ":compile_commands_isystem",
+        action = "build",
+        extra_flags = ["--features=external_include_paths"],
+        output_file = "bazel-bin/compile_commands_isystem/compile_commands.json",
+        contains = ["-isystem external/external_lib"],
+        tags = ["manual"],
+        size = "large",
+    )
+"""
+
+load("@rules_python//python:py_test.bzl", "py_test")
+
+# Source files made available to the inner build via the test runfiles,
+# alongside the runner. Declared as a filegroup in the BUILD file.
+_SRCS = "//test/unit/external_repository:external_test_srcs"
+
+def external_test(
+        name,
+        target,
+        action = "test",
+        extra_flags = [],
+        output_file = None,
+        contains = None,
+        tags = [],
+        size = "large",
+        **kwargs):
+    """Generate a py_test that runs a bazel command in a temp workspace.
+
+    Args:
+        name: Test name.
+        target: Bazel target to act on (e.g. ":codechecker_external_deps").
+        action: Bazel action to run (default: "test").
+        extra_flags: Additional flags to pass to the bazel command.
+        output_file: Optional relative path to an output file to check.
+        contains: Optional list of regex patterns to find in the output file.
+        tags: Additional test tags.
+        size: Test size (default: large).
+        **kwargs: Forwarded to py_test.
+    """
+    if type(contains) == "string":
+        contains = [contains]
+    if type(extra_flags) == "string":
+        extra_flags = [extra_flags]
+
+    python_args = [
+        "--repo_root",
+        "$(rootpath //:MODULE.bazel)",
+        "--action",
+        action,
+        "--target",
+        target,
+    ]
+
+    # Output file assertions
+    if output_file:
+        python_args.extend(["--output_file", output_file])
+    if contains:
+        python_args.append("--contains")
+        python_args.extend(["'{}'".format(pat) for pat in contains])
+
+    # Extra flags go after -- to avoid argparse confusion with --flags
+    if extra_flags:
+        python_args.append("--")
+        python_args.extend(extra_flags)
+
+    py_test(
+        name = name,
+        srcs = ["//test/unit/external_repository:external_test_runner.py"],
+        main = "//test/unit/external_repository:external_test_runner.py",
+        args = python_args,
+        data = [_SRCS, "//:MODULE.bazel"],
+        # No other way to ensure integrated bazel can find the repository
+        local = True,
+        size = size,
+        tags = tags,
+        **kwargs
+    )