fix(builtin): linker test should run program as an action (#1113)

We were accidentally using runfiles resolution to read all user inputs, because we ran as an sh_test

Author: alexeagle

.bazelrc

@@ -35,3 +35,20 @@ import %workspace%/third_party/github.com/bazelbuild/bazel-toolchains/bazelrc/ba
 # Remote instance, borrow the one used by Angular devs
 build:remote --remote_instance_name=projects/internal-200822/instances/default_instance
 build:remote --project_id=internal-200822
+
+# To reproduce Windows issues where there is no runfiles symlink there
+build:no-runfiles --noenable_runfiles
+# workaround https://github.com/bazelbuild/bazel/issues/7994
+build:no-runfiles --spawn_strategy=standalone
+# This config is probably only used while debugging
+build:no-runfiles --define=VERBOSE_LOG=1
+
+# Docker Sandbox Mode
+# Useful for troubleshooting Remote Build Execution problems
+# See https://docs.bazel.build/versions/master/remote-execution-sandbox.html#prerequisites
+build:docker-sandbox --spawn_strategy=docker --strategy=Javac=docker --genrule_strategy=docker
+build:docker-sandbox --define=EXECUTOR=remote
+build:docker-sandbox --experimental_docker_verbose
+build:docker-sandbox --experimental_enable_docker_sandbox
+# This is the same image used on BazelCI rbe_ubuntu1604 job
+build:docker-sandbox --experimental_docker_image=gcr.io/cloud-marketplace/google/rbe-ubuntu16-04

internal/js_library/js_library.bzl

@@ -48,7 +48,10 @@ def write_amd_names_shim(actions, amd_names_shim, targets):
 
 def _js_library(ctx):
     return [
-        DefaultInfo(files = depset(ctx.files.srcs)),
+        DefaultInfo(
+            files = depset(ctx.files.srcs),
+            runfiles = ctx.runfiles(files = ctx.files.srcs),
+        ),
         AmdNamesInfo(names = ctx.attr.amd_names),
     ]
 

internal/linker/BUILD.bazel

@@ -1,4 +1,19 @@
-exports_files(["link_node_modules.js"])
+# BEGIN-INTERNAL
+load("@npm_bazel_typescript//:index.from_src.bzl", "checked_in_ts_library")
+
+# We can't bootstrap the ts_library rule using the linker itself,
+# because the implementation of ts_library depends on the linker so that would be a cycle.
+# So we compile it to JS and check in the result as index.js
+checked_in_ts_library(
+    name = "linker_lib",
+    srcs = ["link_node_modules.ts"],
+    checked_in_js = "index.js",
+    visibility = ["//internal/linker:__subpackages__"],
+    deps = ["@npm//@types/node"],
+)
+
+# END-INTERNAL
+exports_files(["index.js"])
 
 filegroup(
     name = "package_contents",

internal/linker/README.md

@@ -12,6 +12,11 @@ Under Bazel, we have exactly this monorepo feature. But, we want users to have a
 To make this seamless, we run a linker as a separate program inside the Bazel action, right before node.
 It does essentially the same job as Lerna: make sure there is a `$PWD/node_modules` tree and that all the semantics from Bazel (such as `module_name`/`module_root` attributes) are mapped to the node module resolution algorithm, so that the node runtime behaves the same way as if the packages had been installed from npm.
 
+Note that the behavior of the linker depends on whether the package to link was declared as:
+
+1. a runtime dependency of a binary run by Bazel, which we call "statically linked", and which is resolved from Bazel's Runfiles tree or manifest
+1. a dependency declared by a user of that binary, which we call "dynamically linked", and which is resolved from the execution root
+
 In the future the linker should also generate `package.json` files so that things like `main` and `typings` fields are present and reflect the Bazel semantics, so that we can entirely eliminate custom loading and pathmapping logic from binaries we execute.
 
 [lerna]: https://github.com/lerna/lerna

internal/linker/index.js

@@ -20,7 +20,7 @@ def _debug(vars, *args):
 _ASPECT_RESULT_NAME = "link_node_modules__aspect_result"
 
 # Traverse 'srcs' in addition so that we can go across a genrule
-_MODULE_MAPPINGS_DEPS_NAMES = ["deps", "srcs"]
+_MODULE_MAPPINGS_DEPS_NAMES = ["data", "deps", "srcs"]
 
 def register_node_modules_linker(ctx, args, inputs):
     """Helps an action to run node by setting up the node_modules linker as a pre-process
@@ -55,7 +55,12 @@ def register_node_modules_linker(ctx, args, inputs):
     # Write the result to a file, and use the magic node option --bazel_node_modules_manifest
     # The node_launcher.sh will peel off this argument and pass it to the linker rather than the program.
     modules_manifest = ctx.actions.declare_file("_%s.module_mappings.json" % ctx.label.name)
-    ctx.actions.write(modules_manifest, str({"modules": mappings, "root": node_modules_root}))
+    content = {
+        "modules": mappings,
+        "root": node_modules_root,
+        "workspace": ctx.workspace_name,
+    }
+    ctx.actions.write(modules_manifest, str(content))
     args.add("--bazel_node_modules_manifest=%s" % modules_manifest.path)
     inputs.append(modules_manifest)