DO NOT MERGE - Experimental POC for C++ integration tests

BUILD

@@ -42,3 +42,13 @@ filegroup(
     ],
     visibility = ["//:__subpackages__"],
 )
+
+filegroup(
+    name = "all_files_for_testing",
+    srcs = [
+        "BUILD",
+        "WORKSPACE",
+        "MODULE.bazel",
+        "//cc:all_files_for_testing",
+    ]
+)

MODULE.bazel

@@ -32,3 +32,19 @@ bazel_dep(name = "stardoc", version = "0.8.0", dev_dependency = True)
 # Compatibility layer
 compat = use_extension("//cc:extensions.bzl", "compatibility_proxy")
 use_repo(compat, "cc_compatibility_proxy")
+
+bazel_dep(
+    name = "rules_bazel_integration_test",
+    version = "0.36.0",
+    dev_dependency = True,
+)
+
+bazel_binaries = use_extension(
+    "@rules_bazel_integration_test//:extensions.bzl",
+    "bazel_binaries",
+    dev_dependency = True,
+)
+bazel_binaries.download(version_file = "//:.bazelversion")
+bazel_binaries.download(version = "8.5.1")
+bazel_binaries.download(version = "last_green")
+use_repo(bazel_binaries, "bazel_binaries", "bazel_binaries_bazelisk", "build_bazel_bazel_.bazelversion", "build_bazel_bazel_8_5_1", "build_bazel_bazel_last_green")

WORKSPACE

@@ -65,3 +65,31 @@ bazel_features_deps()
 load("//cc:extensions.bzl", "compatibility_proxy_repo")
 
 compatibility_proxy_repo()
+
+http_archive(
+    name = "rules_bazel_integration_test",
+    sha256 = "caadcd3adafc2cdcd4b020cf0ae530ddab4dc61201a9948473909b75a91e9192",
+    urls = [
+        "https://github.com/bazel-contrib/rules_bazel_integration_test/releases/download/v0.35.0/rules_bazel_integration_test.v0.35.0.tar.gz",
+    ],
+)
+
+load("@rules_bazel_integration_test//bazel_integration_test:deps.bzl", "bazel_integration_test_rules_dependencies")
+
+bazel_integration_test_rules_dependencies()
+
+load("@cgrindel_bazel_starlib//:deps.bzl", "bazel_starlib_dependencies")
+
+bazel_starlib_dependencies()
+
+load("@bazel_skylib//:workspace.bzl", "bazel_skylib_workspace")
+
+bazel_skylib_workspace()
+
+load("@rules_bazel_integration_test//bazel_integration_test:defs.bzl", "bazel_binaries")
+
+bazel_binaries(versions = [
+    "//:.bazelversion",
+    "8.5.1",
+    "last_green",
+])

cc/BUILD

@@ -23,8 +23,12 @@ licenses(["notice"])  # Apache 2.0
 filegroup(
     name = "all_files_for_testing",
     srcs = glob(["**"]) + [
+        "//cc/private:srcs",
         "//cc/private/rules_impl:srcs",
         "//cc/private/toolchain:srcs",
+        "//cc/common:srcs",
+        "//cc/proto:srcs",
+        "//cc/toolchains:srcs",
     ],
 )
 

cc/private/BUILD

@@ -38,6 +38,7 @@ filegroup(
         "//cc/private/link:srcs",
         "//cc/private/rules_impl:srcs",
         "//cc/private/toolchain:srcs",
+        "//cc/private/toolchain/test:srcs",
         "//cc/private/toolchain_config:srcs",
     ],
     visibility = ["//visibility:public"],

cc/private/toolchain/test/BUILD

@@ -11,3 +11,12 @@ compat_toolchain(
     toolchain_type = "@bazel_tools//tools/cpp:test_runner_toolchain_type",
     use_target_platform_constraints = True,
 )
+
+filegroup(
+    name = "srcs",
+    srcs = glob([
+        "**/BUILD",
+        "*.bzl",
+    ]),
+    visibility = ["//cc/private:__pkg__"],
+)

cc/proto/BUILD

@@ -2,3 +2,10 @@ package(default_visibility = ["//visibility:public"])
 
 # Toolchain type provided by proto_lang_toolchain rule and used by cc_proto_library
 toolchain_type(name = "toolchain_type")
+
+filegroup(
+    name = "srcs",
+    srcs = glob([
+        "**/BUILD",
+    ]),
+)

tests/integration/BUILD

@@ -0,0 +1,50 @@
+load("@bazel_binaries//:defs.bzl", "bazel_binaries")
+load("@rules_bazel_integration_test//bazel_integration_test:defs.bzl", "default_test_runner")
+load("@rules_bazel_integration_test//bazel_integration_test:defs.bzl", "bazel_integration_test")
+load("@rules_shell//shell:sh_binary.bzl", "sh_binary")
+load("@rules_shell//shell:sh_library.bzl", "sh_library")
+
+sh_library(
+    name = "test_utils",
+    srcs = ["test_utils.sh"],
+)
+
+genrule(
+    name = "no_rebuild_on_irrelevant_header_change_build_gen",
+    srcs = ["no_rebuild_on_irrelevant_header_change/BUILD.test"],
+    outs = ["no_rebuild_on_irrelevant_header_change/BUILD"],
+    cmd = "cp $< $@",
+)
+
+filegroup(
+    name = "no_rebuild_on_irrelevant_header_change_files",
+    srcs = [
+        ":no_rebuild_on_irrelevant_header_change/BUILD",
+    ] + glob(["no_rebuild_on_irrelevant_header_change/**"])
+)
+
+sh_binary(
+    name = "no_rebuild_on_irrelevant_header_change_test_runner",
+    testonly = True,
+    srcs = ["no_rebuild_on_irrelevant_header_change_test_runner.sh"],
+    deps = [
+        ":test_utils",
+        "@rules_shell//shell/runfiles",
+    ],
+    data = [
+        "@rules_bazel_integration_test//tools:create_scratch_dir",
+    ],
+)
+
+bazel_integration_test(
+    name = "no_rebuild_on_irrelevant_header_change_test",
+    test_runner = ":no_rebuild_on_irrelevant_header_change_test_runner",
+    bazel_binaries = bazel_binaries,
+    bazel_version = "8.5.1",
+    workspace_path = "no_rebuild_on_irrelevant_header_change",
+    workspace_files = [
+        ":no_rebuild_on_irrelevant_header_change_files",
+        "//:all_files_for_testing",
+    ],
+    tags = [],
+)

tests/integration/no_rebuild_on_irrelevant_header_change/BUILD.test

@@ -0,0 +1,13 @@
+load("@rules_cc//cc:cc_binary.bzl", "cc_binary")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
+cc_library(
+    name = "b",
+    srcs = ["b1.h", "b2.h"],
+)
+
+cc_binary(
+    name = "a",
+    srcs = ["a.cc"],
+    deps = [":b"],
+)

tests/integration/no_rebuild_on_irrelevant_header_change/MODULE.bazel

@@ -0,0 +1,7 @@
+module(name = "module_under_test")
+
+bazel_dep(name = "rules_cc", version = "0.0.0")
+local_path_override(
+    module_name = "rules_cc",
+    path = "../../..",
+)

tests/integration/no_rebuild_on_irrelevant_header_change/a.cc

@@ -0,0 +1,5 @@
+#include "b1.h"
+
+int main(void) {
+  return B_RETURN_VALUE;
+}

tests/integration/no_rebuild_on_irrelevant_header_change/b1.h

@@ -0,0 +1 @@
+#define B_RETURN_VALUE 31

tests/integration/no_rebuild_on_irrelevant_header_change/b2.h

@@ -0,0 +1 @@
+=== BANANA ===

tests/integration/no_rebuild_on_irrelevant_header_change_test_runner.sh

@@ -0,0 +1,34 @@
+set -euo pipefail
+
+# --- 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
+# shellcheck disable=SC1090
+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 $f"; exit 1; }; f=; set -e
+# --- end runfiles.bash initialization v3 ---
+
+source tests/integration/test_utils.sh
+
+create_scratch_dir_sh_location=rules_bazel_integration_test/tools/create_scratch_dir.sh
+create_scratch_dir_sh="$(rlocation "${create_scratch_dir_sh_location}")" || \
+  (echo >&2 "Failed to locate ${create_scratch_dir_sh_location}" && exit 1)
+
+scratch_dir="$("${create_scratch_dir_sh}" --workspace "${BIT_WORKSPACE_DIR}")"
+
+TEST_log="$scratch_dir/test.log"
+
+# Change into scratch directory
+cd "${scratch_dir}"
+
+"${BIT_BAZEL_BINARY}" build -s //:a &> $TEST_log || fail
+expect_log "Compiling a.cc"
+
+echo "CHERRY" > b2.h
+
+"${BIT_BAZEL_BINARY}" build -s //:a &> $TEST_log || fail
+expect_not_log "Compiling a.cc"

tests/integration/test_utils.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+function fail() {
+    echo "FAILED: $*." >&2
+    exit 1
+}
+
+function expect_log() {
+    local pattern=$1
+    local message=${2:-"Expected regexp '$pattern' not found"}
+    grep -sq -- "$pattern" $TEST_log && return 0
+
+    fail "$message"
+    return 1
+}
+
+function expect_not_log() {
+    local pattern=$1
+    local message=${2:-"Unexpected regexp '$pattern' found"}
+    grep -sq -- "$pattern" $TEST_log || return 0
+
+    fail "$message"
+    return 1
+}