perf(js_run_devserver): run fs operations in parallel

[jbedard]

See individual commits. Primarily changing async fs operations to be run in parallel instead of sequentially.

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Changes are visible to end-users: no

Test plan

• Covered by existing test cases
• Manual testing; please provide instructions so we can reproduce:

[aspect-workflows[bot]]

Test

2 test targets passed

Targets

//js/private/test/js_run_devserver:js_run_devserver_test [k8-fastbuild]                                 392ms
//js/private/test/js_run_devserver:node_modules_symlink_to_execroot_test [k8-fastbuild]                 453ms

Total test execution time was 845ms. 201 tests (99.0%) were fully cached saving 32s.

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Test

e2e/bzlmod

All tests were cache hits

5 tests (100.0%) were fully cached saving 857ms.

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Test

e2e/gyp_no_install_script

All tests were cache hits

2 tests (100.0%) were fully cached saving 503ms.

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Test

e2e/js_image_oci

All tests were cache hits

1 test (100.0%) was fully cached saving 7s.

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Test

e2e/npm_link_package

All tests were cache hits

3 tests (100.0%) were fully cached saving 820ms.

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Test

e2e/npm_link_package-esm

All tests were cache hits

3 tests (100.0%) were fully cached saving 1s.

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Test

e2e/npm_translate_lock

All tests were cache hits

1 test (100.0%) was fully cached saving 34ms.

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Test

e2e/npm_translate_lock_empty

All tests were cache hits

1 test (100.0%) was fully cached saving 34ms.

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Test

e2e/npm_translate_lock_multi

All tests were cache hits

2 tests (100.0%) were fully cached saving 171ms.

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Test

e2e/npm_translate_lock_partial_clone

All tests were cache hits

1 test (100.0%) was fully cached saving 129ms.

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Test

e2e/npm_translate_lock_replace_packages

All tests were cache hits

3 tests (100.0%) were fully cached saving 503ms.

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Test

e2e/npm_translate_lock_subdir_patch

All tests were cache hits

1 test (100.0%) was fully cached saving 222ms.

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Test

e2e/npm_translate_package_lock

All tests were cache hits

1 test (100.0%) was fully cached saving 131ms.

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Test

e2e/npm_translate_yarn_lock

All tests were cache hits

1 test (100.0%) was fully cached saving 131ms.

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Test

e2e/package_json_module

All tests were cache hits

1 test (100.0%) was fully cached saving 590ms.

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Test

e2e/pnpm_lockfiles

All tests were cache hits

40 tests (100.0%) were fully cached saving 3s.

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Test

e2e/pnpm_workspace

All tests were cache hits

10 tests (100.0%) were fully cached saving 3s.

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Test

e2e/pnpm_workspace_rerooted

All tests were cache hits

12 tests (100.0%) were fully cached saving 2s.

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Test

e2e/repo_mapping

All tests were cache hits

2 tests (100.0%) were fully cached saving 474ms.

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Test

e2e/rules_foo

All tests were cache hits

2 tests (100.0%) were fully cached saving 470ms.

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Test

e2e/runfiles

All tests were cache hits

1 test (100.0%) was fully cached saving 443ms.

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Test

e2e/vendored_node

All tests were cache hits

1 test (100.0%) was fully cached saving 199ms.

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