From 00af05d840b44e80a8ace9756e49cb86ea19cdd8 Mon Sep 17 00:00:00 2001
From: Eric <eric@dgren.dev>
Date: Wed, 4 Mar 2026 03:05:01 +0000
Subject: [PATCH] feat: add phase 2 bun_install repository rule bootstrap

---
 README.md                            |  6 ++
 bun/defs.bzl                         |  2 +
 internal/BUILD.bazel                 |  1 +
 internal/bun_install.bzl             | 95 +++++++++++++++++++++++++++-
 tests/install_test/BUILD.bazel       | 21 ++++++
 tests/install_test/clean_install.sh  | 22 +++++++
 tests/install_test/stale_lockfile.sh | 41 ++++++++++++
 7 files changed, 186 insertions(+), 2 deletions(-)
 create mode 100644 internal/BUILD.bazel
 create mode 100644 tests/install_test/BUILD.bazel
 create mode 100755 tests/install_test/clean_install.sh
 create mode 100755 tests/install_test/stale_lockfile.sh

diff --git a/README.md b/README.md
index 7f3275d..a07dae7 100644
--- a/README.md
+++ b/README.md
@@ -10,3 +10,9 @@ Phase 1 bootstrap is in place:
 - Platform-specific Bun repository downloads (`/bun/repositories.bzl`)
 - Toolchain declarations and registration targets (`/bun/BUILD.bazel`)
 - Smoke test for `bun --version` (`//tests/toolchain_test:bun_version_test`)
+
+Phase 2 bootstrap is in place:
+
+- Repository-rule based `bun_install` (`/internal/bun_install.bzl`)
+- Public export via `bun/defs.bzl`
+- Focused install behavior tests (`//tests/install_test:all`)
diff --git a/bun/defs.bzl b/bun/defs.bzl
index bfca96a..220f084 100644
--- a/bun/defs.bzl
+++ b/bun/defs.bzl
@@ -1,8 +1,10 @@
+load("//internal:bun_install.bzl", "bun_install")
 load(":repositories.bzl", "bun_register_toolchains", "bun_repositories")
 load(":toolchain.bzl", "BunToolchainInfo", "bun_toolchain")
 
 __all__ = [
     "BunToolchainInfo",
+    "bun_install",
     "bun_register_toolchains",
     "bun_repositories",
     "bun_toolchain",
diff --git a/internal/BUILD.bazel b/internal/BUILD.bazel
new file mode 100644
index 0000000..ffd0fb0
--- /dev/null
+++ b/internal/BUILD.bazel
@@ -0,0 +1 @@
+package(default_visibility = ["//visibility:public"])
diff --git a/internal/bun_install.bzl b/internal/bun_install.bzl
index b7e5080..9cb4646 100644
--- a/internal/bun_install.bzl
+++ b/internal/bun_install.bzl
@@ -1,2 +1,93 @@
-def bun_install(**_kwargs):
-    fail("bun_install is not implemented yet")
+"""Repository-rule based bun_install implementation."""
+
+def _select_bun_binary(repository_ctx):
+    os_name = repository_ctx.os.name.lower()
+    arch = repository_ctx.os.arch.lower()
+
+    if "linux" in os_name:
+        if arch in ["aarch64", "arm64"]:
+            return repository_ctx.path(repository_ctx.attr.bun_linux_aarch64)
+        return repository_ctx.path(repository_ctx.attr.bun_linux_x64)
+
+    if "mac" in os_name or "darwin" in os_name:
+        if arch in ["aarch64", "arm64"]:
+            return repository_ctx.path(repository_ctx.attr.bun_darwin_aarch64)
+        return repository_ctx.path(repository_ctx.attr.bun_darwin_x64)
+
+    if "windows" in os_name:
+        return repository_ctx.path(repository_ctx.attr.bun_windows_x64)
+
+    fail("Unsupported host platform: os={}, arch={}".format(repository_ctx.os.name, repository_ctx.os.arch))
+
+
+def _bun_install_repository_impl(repository_ctx):
+    package_json = repository_ctx.path(repository_ctx.attr.package_json)
+    bun_lockfile = repository_ctx.path(repository_ctx.attr.bun_lockfile)
+
+    if not package_json.exists:
+        fail("bun_install: package_json not found: {}".format(repository_ctx.attr.package_json))
+
+    if not bun_lockfile.exists:
+        fail("bun_install: bun_lockfile not found: {}".format(repository_ctx.attr.bun_lockfile))
+
+    bun_bin = _select_bun_binary(repository_ctx)
+
+    repository_ctx.symlink(package_json, "package.json")
+    repository_ctx.symlink(bun_lockfile, "bun.lockb")
+
+    result = repository_ctx.execute(
+        [str(bun_bin), "install", "--frozen-lockfile", "--no-progress"],
+        timeout = 600,
+        quiet = False,
+        environment = {"HOME": str(repository_ctx.path("."))},
+    )
+
+    if result.return_code:
+        fail("""bun_install failed running `bun install --frozen-lockfile`.
+stdout:
+{}
+stderr:
+{}
+""".format(result.stdout, result.stderr))
+
+    repository_ctx.file(
+        "BUILD.bazel",
+        """filegroup(
+    name = "node_modules",
+    srcs = glob(["node_modules/**"], allow_empty = False),
+    visibility = ["//visibility:public"],
+)
+""",
+    )
+
+
+_bun_install_repository = repository_rule(
+    implementation = _bun_install_repository_impl,
+    attrs = {
+        "package_json": attr.label(mandatory = True, allow_single_file = True),
+        "bun_lockfile": attr.label(mandatory = True, allow_single_file = True),
+        "bun_linux_x64": attr.label(default = "@bun_linux_x64//:bun", allow_single_file = True),
+        "bun_linux_aarch64": attr.label(default = "@bun_linux_aarch64//:bun", allow_single_file = True),
+        "bun_darwin_x64": attr.label(default = "@bun_darwin_x64//:bun", allow_single_file = True),
+        "bun_darwin_aarch64": attr.label(default = "@bun_darwin_aarch64//:bun", allow_single_file = True),
+        "bun_windows_x64": attr.label(default = "@bun_windows_x64//:bun", allow_single_file = True),
+    },
+)
+
+
+def bun_install(name, package_json, bun_lockfile):
+    """Create an external repository containing installed node_modules.
+
+    Usage (WORKSPACE):
+      bun_install(
+          name = "node_modules",
+          package_json = "//:package.json",
+          bun_lockfile = "//:bun.lockb",
+      )
+    """
+
+    _bun_install_repository(
+        name = name,
+        package_json = package_json,
+        bun_lockfile = bun_lockfile,
+    )
diff --git a/tests/install_test/BUILD.bazel b/tests/install_test/BUILD.bazel
new file mode 100644
index 0000000..f23b708
--- /dev/null
+++ b/tests/install_test/BUILD.bazel
@@ -0,0 +1,21 @@
+sh_test(
+    name = "bun_install_clean_install_test",
+    srcs = ["clean_install.sh"],
+    args = ["$(location @bun_linux_x64//:bun)"],
+    data = ["@bun_linux_x64//:bun"],
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+)
+
+sh_test(
+    name = "bun_install_stale_lockfile_test",
+    srcs = ["stale_lockfile.sh"],
+    args = ["$(location @bun_linux_x64//:bun)"],
+    data = ["@bun_linux_x64//:bun"],
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:linux",
+    ],
+)
diff --git a/tests/install_test/clean_install.sh b/tests/install_test/clean_install.sh
new file mode 100755
index 0000000..93647f9
--- /dev/null
+++ b/tests/install_test/clean_install.sh
@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+bun_path="$1"
+workdir="$(mktemp -d)"
+trap 'rm -rf "${workdir}"' EXIT
+
+cat > "${workdir}/package.json" <<'JSON'
+{
+  "name": "clean-install-test",
+  "version": "1.0.0"
+}
+JSON
+
+"${bun_path}" install --cwd "${workdir}" >/dev/null
+rm -rf "${workdir}/node_modules"
+"${bun_path}" install --cwd "${workdir}" --frozen-lockfile >/dev/null
+
+if [[ ! -d "${workdir}/node_modules" ]]; then
+  echo "Expected node_modules to be created" >&2
+  exit 1
+fi
diff --git a/tests/install_test/stale_lockfile.sh b/tests/install_test/stale_lockfile.sh
new file mode 100755
index 0000000..e21cfd2
--- /dev/null
+++ b/tests/install_test/stale_lockfile.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+bun_path="$1"
+workdir="$(mktemp -d)"
+trap 'rm -rf "${workdir}"' EXIT
+
+cat > "${workdir}/package.json" <<'JSON'
+{
+  "name": "stale-lockfile-test",
+  "version": "1.0.0"
+}
+JSON
+
+"${bun_path}" install --cwd "${workdir}" >/dev/null
+
+cat > "${workdir}/package.json" <<'JSON'
+{
+  "name": "stale-lockfile-test",
+  "version": "1.0.0",
+  "dependencies": {
+    "left-pad": "1.3.0"
+  }
+}
+JSON
+
+set +e
+output="$(${bun_path} install --cwd "${workdir}" --frozen-lockfile 2>&1)"
+code=$?
+set -e
+
+if [[ ${code} -eq 0 ]]; then
+  echo "Expected frozen lockfile install to fail when package.json changes" >&2
+  exit 1
+fi
+
+if [[ "${output}" != *"lockfile"* && "${output}" != *"frozen"* ]]; then
+  echo "Expected lockfile-related error, got:" >&2
+  echo "${output}" >&2
+  exit 1
+fi