test: Add tests for various OSes and Bazel versions (#17)

.bazelrc

@@ -14,3 +14,8 @@ test --test_verbose_timeout_warnings
 # For testing convenience
 common --heap_dump_on_oom
 test --test_output=errors
+
+# For `hermetic_cc_toolchain`
+common --enable_platform_specific_config
+build:linux --sandbox_add_mount_pair=/tmp
+build:macos --sandbox_add_mount_pair=/var/tmp

.bcr/presubmit.yml

@@ -4,7 +4,6 @@ bcr_test_module:
   matrix:
     platform:
       - "debian10"
-      - "macos"
       - "ubuntu2004"
     bazel:
       - "6.x"
@@ -14,5 +13,5 @@ bcr_test_module:
       name: "Run test module"
       platform: ${{ platform }}
       bazel: ${{ bazel }}
-      build_targets:
+      test_targets:
         - "//..."

.github/actions/setup/action.yml

@@ -1,14 +1,34 @@
 ---
 name: Set up environment
 
+inputs:
+  bazel-version:
+    description: Bazel version
+    required: true
+
 runs:
   using: composite
   steps:
+    - name: Generate .bazeliskrc
+      shell: bash
+      run: |
+        echo "USE_BAZEL_VERSION=${{ inputs.bazel-version }}" > .bazeliskrc
+        echo "USE_BAZEL_VERSION=${{ inputs.bazel-version }}" > examples/.bazeliskrc
     - name: Install bazelisk
       shell: bash
       run: |
-        bazelisk_dir="$(realpath "$(mktemp -d -p .)")"
-        wget https://github.com/bazelbuild/bazelisk/releases/download/v1.19.0/bazelisk-linux-amd64 \
+        bazelisk_dir=bazelisk-bin-dir
+        mkdir "${bazelisk_dir}"
+        if [ "${RUNNER_OS}" == "Linux" ]; then
+          part_os="linux"
+        elif [ "${RUNNER_OS}" == "macOS" ]; then
+          part_os="darwin"
+        else
+          echo "${RUNNER_OS} not supported"
+          exit 1
+        fi
+
+        wget "https://github.com/bazelbuild/bazelisk/releases/download/v1.19.0/bazelisk-${part_os}-amd64" \
           -O "${bazelisk_dir}/bazelisk"
         chmod +x "${bazelisk_dir}/bazelisk"
         echo "${bazelisk_dir}" >> "${GITHUB_PATH}"

.github/workflows/tests.yml

@@ -12,26 +12,46 @@ concurrency:
 
 jobs:
   unit-test:
-    runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        bazel-version:
+          - 6.5.0
+          - 7.1.1
+        runner:
+          - ubuntu-20.04
+          - ubuntu-22.04
+    runs-on: ${{ matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
         with:
           ref: ${{ github.head_ref }}
       - name: Set up
         uses: ./.github/actions/setup
+        with:
+          bazel-version: ${{ matrix.bazel-version }}
       - name: Run unit tests
         run: ./scripts/execute_tests.bash
 
   example:
-    runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        bazel-version:
+          - 6.5.0
+          - 7.1.1
+        runner:
+          - ubuntu-20.04
+          - ubuntu-22.04
+    runs-on: ${{ matrix.runner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
         with:
           ref: ${{ github.head_ref }}
       - name: Set up
         uses: ./.github/actions/setup
+        with:
+          bazel-version: ${{ matrix.bazel-version }}
       - name: Validate example
         run: ./scripts/validate_example.bash
 

.gitignore

@@ -1,3 +1,7 @@
 # Bazel
 /bazel-*
 MODULE.bazel.lock
+.bazeliskrc
+
+# For CI
+/bazelisk-bin-dir

MODULE.bazel

@@ -7,20 +7,22 @@ module(
 )
 
 bazel_dep(name = "bazel_skylib", version = "1.5.0", dev_dependency = True)
-bazel_dep(name = "toolchains_llvm", version = "1.0.0", dev_dependency = True)
-
-llvm = use_extension(
-    "@toolchains_llvm//toolchain/extensions:llvm.bzl",
-    "llvm",
+bazel_dep(
+    name = "hermetic_cc_toolchain",
+    version = "3.0.1",
     dev_dependency = True,
 )
-llvm.toolchain(
-    llvm_version = "17.0.6",
+
+cc_toolchains = use_extension(
+    "@hermetic_cc_toolchain//toolchain:ext.bzl",
+    "toolchains",
+    dev_dependency = True,
 )
-use_repo(llvm, "llvm_toolchain")
+use_repo(cc_toolchains, "zig_sdk")
 
 register_toolchains(
-    "@llvm_toolchain//:all",
+    "@zig_sdk//toolchain:linux_amd64_gnu.2.31",
+    "@zig_sdk//toolchain:linux_arm64_gnu.2.31",
     dev_dependency = True,
 )
 

build_script/check_emptiness.bash

@@ -66,9 +66,11 @@ if [[ "${#files_to_touch[@]}" -gt 0 ]]; then
     trap 'touch "${files_to_touch[@]}"' EXIT
 fi
 
-for file_to_check in "${files_to_check[@]}"; do
-    exit_if_empty_file "${file_to_check}"
-done
+if [[ "${#files_to_check[@]}" -gt 0 ]]; then
+    for file_to_check in "${files_to_check[@]}"; do
+        exit_if_empty_file "${file_to_check}"
+    done
+fi
 
 # Exit with error if there's no empty file
 echo "${error_message}" >&2

build_script/conditionally_execute.bash

@@ -89,9 +89,11 @@ if [[ "${#files_to_touch[@]}" -gt 0 ]]; then
     trap 'touch "${files_to_touch[@]}"' EXIT
 fi
 
-for file_to_check in "${files_to_check[@]}"; do
-    exit_if_empty_file "${file_to_check}"
-done
+if [[ "${#files_to_check[@]}" -gt 0 ]]; then
+    for file_to_check in "${files_to_check[@]}"; do
+        exit_if_empty_file "${file_to_check}"
+    done
+fi
 
 if [[ "${ignore_error}" == "true" ]]; then
     "$@" >"${stdout_file:-"/dev/null"}" 2>"${stderr_file:-"/dev/null"}" || true

examples/.bazelignore

@@ -0,0 +1 @@
+../.bazelignore

examples/.bazelrc

@@ -0,0 +1 @@
+../.bazelrc

examples/.gitignore

@@ -1,7 +1,5 @@
 # Copied from the original workspace
-.bazelrc
 .bazeliskrc
-.bazelignore
 
 # Bazel
 /bazel-*

examples/MODULE.bazel

@@ -12,16 +12,23 @@ local_path_override(
     path = "..",
 )
 
-# Register LLVM toolchain for C/C++
-bazel_dep(name = "toolchains_llvm", version = "1.0.0")
+# For testing utility
+bazel_dep(name = "bazel_skylib", version = "1.5.0")
 
-llvm = use_extension(
-    "@toolchains_llvm//toolchain/extensions:llvm.bzl",
-    "llvm",
+# Register toolchain for C/C++
+
+bazel_dep(
+    name = "hermetic_cc_toolchain",
+    version = "3.0.1",
 )
-llvm.toolchain(
-    llvm_version = "17.0.6",
+
+cc_toolchains = use_extension(
+    "@hermetic_cc_toolchain//toolchain:ext.bzl",
+    "toolchains",
 )
-use_repo(llvm, "llvm_toolchain")
+use_repo(cc_toolchains, "zig_sdk")
 
-register_toolchains("@llvm_toolchain//:all")
+register_toolchains(
+    "@zig_sdk//toolchain:linux_amd64_gnu.2.31",
+    "@zig_sdk//toolchain:linux_arm64_gnu.2.31",
+)

examples/cc/BUILD.bazel

@@ -1,3 +1,4 @@
+load("@bazel_skylib//rules:build_test.bzl", "build_test")
 load("@rules_build_error//lang/cc:defs.bzl", "cc_build_error")
 load("@rules_build_error//matcher:defs.bzl", "matcher")
 
@@ -6,3 +7,10 @@ cc_build_error(
     src = "compile_error.cpp",
     compile_stderr = matcher.has_substr("Example compile error"),
 )
+
+build_test(
+    name = "build_test",
+    targets = [
+        ":example",
+    ],
+)

scripts/execute_tests.bash

@@ -4,6 +4,8 @@
 
 set -euo pipefail
 
+BAZEL_VERSION_DEFAULT="7.1.1"
+
 # Bazel executable with some arguments
 BAZEL_EXECUTABLE=(
     "env"
@@ -35,6 +37,13 @@ check_bazel_build_error() {
     fi
 }
 
+
+if [[ ! -f .bazeliskrc ]]; then
+    echo "WARN: .bazeliskrc not found." >&2
+    echo "WARN: Creating it with a default version ${BAZEL_VERSION_DEFAULT}." >&2
+    echo "USE_BAZEL_VERSION=7.1.1" > .bazeliskrc
+fi
+
 echo "Executing the test cases which should succeed in straightforward 'bazel test'"
 "${BAZEL_EXECUTABLE[@]}" test //...
 

scripts/validate_example.bash

@@ -4,6 +4,8 @@
 
 set -euo pipefail
 
+BAZEL_VERSION_DEFAULT="7.1.1"
+
 # Bazel executable with some arguments
 BAZEL_EXECUTABLE=(
     "env"
@@ -15,16 +17,12 @@ BAZEL_EXECUTABLE=(
     bazelisk
 )
 
-copied_files=(
-    ".bazelignore"
-    ".bazeliskrc"
-    ".bazelrc"
-)
-
-for copied_file in "${copied_files[@]}"; do
-    cp "${copied_file}" examples
-done
-
 cd examples
 
-"${BAZEL_EXECUTABLE[@]}" build //...
+if [[ ! -f .bazeliskrc ]]; then
+    echo "WARN: .bazeliskrc not found." >&2
+    echo "WARN: Creating it with a default version ${BAZEL_VERSION_DEFAULT}." >&2
+    echo "USE_BAZEL_VERSION=7.1.1" > .bazeliskrc
+fi
+
+"${BAZEL_EXECUTABLE[@]}" test //...