Vendor dependencies

Let's see how I like this workflow.

vendor/cxx/tools/buck/prelude/sh_test.bzl

@@ -0,0 +1,60 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under both the MIT license found in the
+# LICENSE-MIT file in the root directory of this source tree and the Apache
+# License, Version 2.0 found in the LICENSE-APACHE file in the root directory
+# of this source tree.
+
+load("@prelude//test/inject_test_run_info.bzl", "inject_test_run_info")
+
+def sh_test_impl(ctx: "context") -> ["provider"]:
+    # This does not exist in v1 either, but v1 has those attributes presumably
+    # to be compatible with this. We just fail if they're passed.
+    if ctx.attrs.list_args or ctx.attrs.list_env or ctx.attrs.run_args or ctx.attrs.run_env:
+        fail("An unsupported attribute was passed")
+
+    args = cmd_args()
+
+    if ctx.attrs.test != None:
+        if type(ctx.attrs.test) == "artifact":
+            args.add(ctx.attrs.test)
+        elif type(ctx.attrs.test) == "dependency":
+            run_info = ctx.attrs.test.get(RunInfo)
+            if run_info != None:
+                args.add(run_info.args)
+            else:
+                info = ctx.attrs.test[DefaultInfo]
+                args.add(info.default_outputs).hidden(info.other_outputs)
+        else:
+            fail("Unexpected type for test attribute")
+
+    args.hidden(ctx.attrs.resources)
+
+    deps = []
+    for dep in ctx.attrs.deps:
+        info = dep[DefaultInfo]
+        deps.extend(info.default_outputs)
+        deps.extend(info.other_outputs)
+
+    args.hidden(deps)
+
+    command = [args] + ctx.attrs.args
+
+    run_from_project_root = "buck2_run_from_project_root" in (ctx.attrs.labels or [])
+
+    # TODO support default info and runinfo properly by writing a sh script that invokes the command properly
+
+    return inject_test_run_info(
+        ctx,
+        ExternalRunnerTestInfo(
+            type = ctx.attrs.type or "custom",
+            command = command,
+            env = ctx.attrs.env,
+            labels = ctx.attrs.labels,
+            contacts = ctx.attrs.contacts,
+            run_from_project_root = run_from_project_root,
+            use_project_relative_paths = run_from_project_root,
+        ),
+    ) + [
+        DefaultInfo(),
+    ]