Duplicate module mapping

[m0ar]

Hi!

Thanks for a great project! We are in the process of migrating build system to Bazel, but I'm facing some problems regarding local typescript dependencies in combination with nodejs_binary. Two local libs have some overlapping dependencies, which seems to trip build_bazel_rules_nodejs/internal/common/module_mappings.bzl.

I'll describe the setup:
libs/auth, libs/compiler, and app have a package.json each, and a corresponding npm_install(...) in the workspace root.
app has the following build declaration:

ts_project(
    name = "cli",
    srcs = glob(["src/**/*.ts"]),
    tsconfig = ":tsconfig",
    args = [
      '--downlevelIteration'
    ],
    declaration = True,
    link_workspace_root = True,
    deps = [
      "//libs/auth",
      "//libs/compiler",
      "@cli_deps//@google-cloud/bigquery",
      "@cli_deps//@types/node",
      "etc"
    ],
)

nodejs_binary(
    name = "evl",
    data = [
        ":cli",
    ],
    entry_point = ":src/index.ts",

The ts_project target builds just fine, but the binary evl fails with the following error, hinting that the overlap in dependencies is an issue even though they are referred to through different repos (cli_deps, auth_deps, and compiler_deps):

ERROR: /home/m0ar/dev/nortical/evl/cli/BUILD.bazel:12:11: in @build_bazel_rules_nodejs//internal/common:module_mappings.bzl%module_mappings_runtime_aspect aspect on ts_project rule //cli:cli: 
Traceback (most recent call last):
        File "/home/m0ar/.cache/bazel/_bazel_m0ar/cb47b4cd868d3f4af276b5193d26e88c/external/build_bazel_rules_nodejs/internal/common/module_mappings.bzl", line 106, column 36, in _module_mappings_runtime_aspect_impl
                mappings = _get_module_mappings(target, ctx)
        File "/home/m0ar/.cache/bazel/_bazel_m0ar/cb47b4cd868d3f4af276b5193d26e88c/external/build_bazel_rules_nodejs/internal/common/module_mappings.bzl", line 67, column 21, in _get_module_mappings
                fail(("duplicate module mapping at %s: %s maps to both %s and %s" %
Error in fail: duplicate module mapping at //cli:cli: @types/node maps to both compiler_deps/node_modules/@types/node and auth_deps/node_modules/@types/node deps
ERROR: Analysis of target '//cli:evl' failed; build aborted: 
INFO: Elapsed time: 0.061s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (0 packages loaded, 0 targets configured)

Any advice for making sense of this?

[m0ar]

When removing @types/node from all but one of the projects, it moves on to the next overlapping dependency. This is still very problematic though since it leads to manual dependency management hell. It even triggers on overlapping transient dependencies. Surely there must be something that I am missing?

I have also tried swapping npm for yarn but the same issue persists.

[m0ar]

Thanks to @duarten , this was resolved by adding exports_directories_only = False in the calls to npm_install 🎊

( see #3067 (comment) )