Add tests

examples/.bazelrc

@@ -1,3 +1,5 @@
+common --tool_java_runtime_version=remotejdk_17
+
 # These settings make it harder for bazel_env to do its job and are here to
 # verify it still works.
 common --incompatible_disallow_empty_glob

examples/BUILD.bazel

@@ -1,5 +1,5 @@
-load("@bazel_env.bzl", "bazel_env")
 load("@buildozer//:buildozer.bzl", "BUILDOZER_LABEL")
+load("@bazel_env.bzl", "bazel_env")
 
 bazel_env(
     name = "bazel_env",
@@ -14,5 +14,34 @@ bazel_env(
         "go": "@rules_go//go",
         "jar": "$(JAVABASE)/bin/jar",
         "java": "$(JAVA)",
+        "jq": ":jq",
     },
 )
+
+alias(
+    name = "jq",
+    actual = select({
+        "@platforms//os:linux": "@jq_linux_amd64//file",
+        "@platforms//os:macos": "@jq_macos_amd64//file",
+        "@platforms//os:windows": "@jq_windows_amd64//file",
+    }),
+)
+
+# Lines below are not part of the example, they are used to test the example.
+
+sh_test(
+    name = "bazel_env_test",
+    srcs = ["bazel_env_test.sh"],
+    data = [
+        # Used to cd into the workspace directory.
+        "MODULE.bazel",
+        # Enforces that the bazel_env has been built.
+        ":bazel_env",
+    ],
+    tags = [
+        # The test only depends on the bazel_env fake outputs, not the individual tools.
+        "external",
+        # The test cd's into the workspace directory and expects the bazel_env to be present.
+        "local",
+    ],
+)

examples/MODULE.bazel

@@ -10,7 +10,35 @@ local_path_override(
 )
 
 bazel_dep(name = "buildifier_prebuilt", version = "6.4.0")
-bazel_dep(name = "buildozer", version = "7.1.1.1")
+bazel_dep(name = "buildozer", version = "7.1.2")
 bazel_dep(name = "rules_go", version = "0.47.1")
 bazel_dep(name = "rules_java", version = "7.5.0")
 bazel_dep(name = "platforms", version = "0.0.10")
+
+# Don't update the versions below, they are only used to verify the hermeticity of bazel_env.
+
+go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")
+go_sdk.download(version = "1.20.14")
+
+http_file = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_file")
+
+http_file(
+    name = "jq_linux_amd64",
+    executable = True,
+    integrity = "sha256-xrOn19PntwxvUbcGo7kL0BgzhGxU0yyjLwAn8AIm/20=",
+    urls = ["https://github.com/jqlang/jq/releases/download/jq-1.5/jq-linux64"],
+)
+
+http_file(
+    name = "jq_macos_amd64",
+    executable = True,
+    integrity = "sha256-OG6SyYKlb+SFFGjXqTHfyilWDO4wag5mxqG9QGXT2sU=",
+    urls = ["https://github.com/jqlang/jq/releases/download/jq-1.5/jq-osx-amd64"],
+)
+
+http_file(
+    name = "jq_windows_amd64",
+    executable = True,
+    integrity = "sha256-6+zYQLpH779mgihoF4zHIaFRBgk396xAbj0xvQFb3pQ=",
+    urls = ["https://github.com/jqlang/jq/releases/download/jq-1.5/jq-win64.exe"],
+)

examples/bazel_env_test.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+build_workspace_directory="$(dirname "$(readlink -f MODULE.bazel)")"
+
+# Run a command with a minimal PATH including the bazel_env and assert its
+# output, possibly with wildcards.
+function assert_cmd_output() {
+  local -r cmd="$1"
+  local -r expected_output="$2"
+
+  local -r bazel_env="$build_workspace_directory/bazel-out/bazel_env-opt/bin/bazel_env/bin"
+  local -r actual_output="$(PATH="$bazel_env:/bin" $cmd 2>&1 | head -n 1 || true)"
+
+  # Allow for wildcard matching first.
+  if [[ $actual_output == $expected_output ]]; then
+    return
+  fi
+  diff <(echo "$expected_output") <(echo "$actual_output") || exit 1
+}
+
+function assert_contains() {
+  local -r pattern="$1"
+  local -r content="$2"
+
+  echo "$content" | grep -sqF -- "$pattern" || {
+    echo "Expected to find '$pattern' in:"
+    echo "$content"
+    exit 1
+  }
+}
+
+#### Status script ####
+
+# Place a fake direnv tool on the PATH.
+tmpdir=$(mktemp -d 2>/dev/null || mktemp -d -t 'tmpdir')
+trap 'rm -rf "$tmpdir"' EXIT
+touch "$tmpdir/direnv"
+chmod +x "$tmpdir/direnv"
+
+# Imitate a bazel run environment for the status script.
+status_out=$(PATH="$tmpdir:$build_workspace_directory/bazel-out/bazel_env-opt/bin/bazel_env/bin:/bin:/usr/bin" \
+BUILD_WORKSPACE_DIRECTORY="$build_workspace_directory" \
+  ./bazel_env.sh)
+
+assert_contains "direnv is installed" "$status_out"
+
+#### Tools ####
+
+assert_cmd_output "bazel-cc" "* error: no input files"
+assert_cmd_output "buildifier --version" "buildifier version: 6.4.0 "
+assert_cmd_output "buildozer --version" "buildozer version: 7.1.2 "
+case "$(arch)" in
+  x86_64) goarch="amd64";;
+  *) goarch="$(arch)";;
+esac
+assert_cmd_output "go version" "go version go1.20.14 $(uname|tr '[:upper:]' '[:lower:]')/$goarch"
+assert_cmd_output "jar --version" "jar 17.0.8.1"
+assert_cmd_output "java --version" "openjdk 17.0.8.1 2023-08-24 LTS"
+assert_cmd_output "jq --version" "jq-1.5"
+
+#### Toolchains ####
+
+[[ -d "$build_workspace_directory/bazel-out/bazel_env-opt/bin/bazel_env/toolchains/cc_toolchain" ]]
+assert_cmd_output "$build_workspace_directory/bazel-out/bazel_env-opt/bin/bazel_env/toolchains/jdk/bin/java --version" "openjdk 17.0.8.1 2023-08-24 LTS"

status.sh.tpl

@@ -36,7 +36,7 @@ cleaned=0
 for f in '{{bin_dir}}'/*;
 do
   if basename "$f" | grep -q -v '{{tools_regex}}'; then
-    rm -rf "$f"
+    rm -rf ./"$f"
     cleaned=1
   fi
 done