chore: add //bzlmod:hello_world_test and use it as BCR presubmit (#…

…2347)

- Create `bzlmod/hello_world` package based upon
`examples/bzlmod/hello_world`.
- Add `rules_bazel_integration_test` so that `//bzlmod:hello_world_test`
can be executed as a test from the parent workspace.
- Add `filegroup` targets named `all_files` to collect files for all of
the packages that are necessary to use `rules_rust`. These are an input
to the `rules_bazel_integration_test` test.
- Replace `.bcr/presubmit.yml` to test `//bzlmod:hello_world_test`.
- Update CI to test `//bzlmod:hello_world_test`.

Related to
bazelbuild/bazel-central-registry#1199 (comment).

.bazelci/presubmit.yml

@@ -624,6 +624,18 @@ tasks:
       - "//:nix_cross_compiling"
     test_targets:
       - "//..."
+  ubuntu2004_bzlmod_bcr:
+    name: bzlmod BCR presubmit
+    platform: ubuntu2004
+    working_directory: bzlmod/hello_world
+    build_targets:
+      - "//..."
+  macos_bzlmod_bcr:
+    name: bzlmod BCR presubmit
+    platform: macos
+    working_directory: bzlmod/hello_world
+    build_targets:
+      - "//..."
 
 buildifier:
   version: latest

.bazelignore

@@ -1,3 +1,4 @@
+bzlmod
 docs
 examples
 crate_universe/private/bootstrap

.bcr/presubmit.yml

@@ -0,0 +1,11 @@
+bcr_test_module:
+  module_path: ""
+  matrix:
+    platform: ["macos", "ubuntu2004"]
+  tasks:
+    run_tests:
+      working_directory: bzlmod/hello_world
+      name: "Run test module"
+      platform: ${{ platform }}
+      test_targets:
+        - "//..."

.gitignore

@@ -5,6 +5,7 @@
 
 # bazel
 /bazel-*
+/bzlmod/hello_world/bazel-*
 /examples/bazel-*
 /examples/cargo_manifest_dir/external_crate/bazel-*
 /examples/crate_universe/bazel-*

bzlmod/hello_world/.bazelrc

@@ -0,0 +1,6 @@
+# Required on windows
+common --enable_platform_specific_config
+startup --windows_enable_symlinks
+build:windows --enable_runfiles
+
+build --experimental_enable_bzlmod

bzlmod/hello_world/BUILD.bazel

@@ -0,0 +1,27 @@
+load("@rules_rust//rust:defs.bzl", "rust_binary", "rust_doc")
+
+package(default_visibility = ["//visibility:public"])
+
+rust_binary(
+    name = "hello_world",
+    srcs = ["src/main.rs"],
+)
+
+rust_doc(
+    name = "hello_world_doc",
+    crate = ":hello_world",
+)
+
+sh_test(
+    name = "hello_world_test",
+    srcs = ["hello_world_test.sh"],
+    args = [
+        "$(rootpath :hello_world)",
+    ],
+    data = [
+        ":hello_world",
+    ],
+    deps = [
+        "@bazel_tools//tools/bash/runfiles",
+    ],
+)

bzlmod/hello_world/MODULE.bazel

@@ -0,0 +1,19 @@
+module(
+    name = "hello_world_example",
+    version = "0.0.0",
+)
+
+bazel_dep(name = "rules_rust", version = "0.0.0")
+local_path_override(
+    module_name = "rules_rust",
+    path = "../..",
+)
+
+rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
+rust.toolchain(edition = "2021")
+use_repo(
+    rust,
+    "rust_toolchains",
+)
+
+register_toolchains("@rust_toolchains//:all")