feat: implement phase 5 bun_bundle bootstrap

tests/bundle_test/BUILD.bazel

@@ -0,0 +1,48 @@
+load("//bun:defs.bzl", "bun_bundle")
+
+bun_bundle(
+    name = "simple_bundle",
+    entry_points = ["main.ts"],
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+)
+
+bun_bundle(
+    name = "minified_bundle",
+    entry_points = ["main.ts"],
+    minify = True,
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+)
+
+sh_test(
+    name = "bundle_output_test",
+    srcs = ["verify_bundle.sh"],
+    args = ["$(location :simple_bundle)"],
+    data = [":simple_bundle"],
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+)
+
+sh_test(
+    name = "bundle_minify_test",
+    srcs = ["verify_minify.sh"],
+    args = [
+        "$(location :simple_bundle)",
+        "$(location :minified_bundle)",
+    ],
+    data = [
+        ":simple_bundle",
+        ":minified_bundle",
+    ],
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+)

tests/bundle_test/main.ts

@@ -0,0 +1,5 @@
+export function greet(name: string): string {
+  return `Hello ${name}`;
+}
+
+console.log(greet("bundle"));

tests/bundle_test/verify_bundle.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+bundle="$1"
+
+if [[ ! -f "${bundle}" ]]; then
+  echo "Bundle output not found: ${bundle}" >&2
+  exit 1
+fi
+
+if [[ ! -s "${bundle}" ]]; then
+  echo "Bundle output is empty: ${bundle}" >&2
+  exit 1
+fi

tests/bundle_test/verify_minify.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+bundle="$1"
+minified="$2"
+
+bundle_size="$(wc -c < "${bundle}")"
+minified_size="$(wc -c < "${minified}")"
+
+if (( minified_size >= bundle_size )); then
+  echo "Expected minified bundle (${minified_size}) to be smaller than regular bundle (${bundle_size})" >&2
+  exit 1
+fi