test: add an example Bazel module that uses the jsonnet module

This is mostly so that I can set it up to be used in the module registry presubmit,
but it does also act as an example.

Author: johnbartholomew

examples/bazel/.bazelrc

@@ -0,0 +1 @@
+common --lockfile_mode=off

examples/bazel/.gitignore

@@ -0,0 +1 @@
+MODULE.bazel.lock

examples/bazel/BUILD

@@ -0,0 +1,27 @@
+load("@rules_python//python:defs.bzl", "py_binary")
+
+cc_binary(
+    name = "use_cpp_lib",
+    srcs = ["use_cpp_lib.cc"],
+    deps = ["@jsonnet//cpp:libjsonnet++"],
+)
+
+cc_binary(
+    name = "use_c_lib",
+    srcs = ["use_c_lib.c"],
+    deps = ["@jsonnet//core:libjsonnet"],
+)
+
+py_binary(
+    name = "use_py_module",
+    srcs = ["use_py_module.py"],
+    deps = ["@jsonnet//python:_jsonnet"],
+)
+
+genrule(
+    name = "use_jsonnet_cmd",
+    srcs = ["example.jsonnet"],
+    outs = ["example.out"],
+    cmd = "$(location @jsonnet//cmd:jsonnet) $< > $@",
+    tools = ["@jsonnet//cmd:jsonnet"],
+)

examples/bazel/MODULE.bazel

@@ -0,0 +1,5 @@
+# Example of using jsonnet by depending on the Bazel module.
+
+bazel_dep(name = "rules_python", version = "1.2.0")
+bazel_dep(name = "jsonnet")
+local_path_override(module_name = "jsonnet", path = "../..")

examples/bazel/example.jsonnet

@@ -0,0 +1,8 @@
+local Person(name='Alice') = {
+  name: name,
+  welcome: 'Hello ' + name + '!',
+};
+{
+  person1: Person(),
+  person2: Person('Bob'),
+}

examples/bazel/expect.out

@@ -0,0 +1,10 @@
+{
+   "person1": {
+      "name": "Alice",
+      "welcome": "Hello Alice!"
+   },
+   "person2": {
+      "name": "Bob",
+      "welcome": "Hello Bob!"
+   }
+}

examples/bazel/use_c_lib.c

@@ -0,0 +1,22 @@
+#include <libjsonnet.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv) {
+    int ret = 0;
+    fprintf(stderr, "Jsonnet version: %s\n", jsonnet_version());
+    struct JsonnetVm *vm = jsonnet_make();
+    if (!vm) { return 1; }
+
+    int err = 0;
+    char *result = jsonnet_evaluate_file(vm, "example.jsonnet", &err);
+    if (!err) {
+        fprintf(stdout, "%s\n", result ? result : "-- no output --");
+    } else {
+        fprintf(stderr, "%s\n", result ? result : "-- no output --");
+        ret = 2;
+    }
+
+    jsonnet_destroy(vm);
+    return ret;
+}

examples/bazel/use_cpp_lib.cc

@@ -0,0 +1,22 @@
+#include <libjsonnet++.h>
+#include <iostream>
+
+int main(int argc, char **argv) {
+    int ret = 0;
+    std::cerr << "Jsonnet version: " << jsonnet::Jsonnet::version() << std::endl;
+
+    jsonnet::Jsonnet vm;
+    if (!vm.init()) {
+        return 1;
+    }
+
+    std::string result;
+    bool ok = vm.evaluateFile("example.jsonnet", &result);
+    if (ok) {
+        std::cout << result << std::endl;
+    } else {
+        std::cerr << vm.lastError() << std::endl;
+        ret = 2;
+    }
+    return ret;
+}

examples/bazel/use_py_module.py

@@ -0,0 +1,5 @@
+import sys
+import _jsonnet
+
+result = _jsonnet.evaluate_file("example.jsonnet")
+sys.stdout.write(result)