[golden-util] Add tests, and other improvements

This CL adds unit tests to golden-util. Thinking through the correct
behavior for tests led to some changes, so this CL also:

* Makes test mode fail if there are extra files in goldens.txt that are
  no longer generated (which regen will remove). It used to succeed,
  meaning you could remove a golden_test entry and forget to regen,
  leading to a confusing unrelated change in the next CL that regens.

* Disallows golden subdirectories. This has been enforced since
  I75e36ed0cfba13a1f12f75a3ea41e1418f2becf4 by golden_test.gni because
  we didn't need it, and doing so greatly simplified path manipulations.
  This CL removes the unused functionality from golden-util.

* Tightens manifest validation (check for missing JSON fields, check for
  duplicates among the generated paths) and adds goldens.txt validation.

* Replaces uses of ioutil (see https://golang.org/doc/go1.16#ioutil).

Test: fx test golden_util_tests
Change-Id: I6eeb0c7f581b9663e12bcc784045b583086cc0a1
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/511058
Commit-Queue: Mitchell Kember <mkember@google.com>
Reviewed-by: Pascal Perez <pascallouis@google.com>
4 files changed
tree: 4550209f17106c13fd2b8dda263420fadc18e825
  1. boards/
  2. build/
  3. buildtools/
  4. bundles/
  5. docs/
  6. examples/
  7. garnet/
  8. products/
  9. scripts/
  10. sdk/
  11. src/
  12. third_party/
  13. tools/
  14. zircon/
  15. .clang-format
  16. .clang-tidy
  17. .git-blame-ignore-revs
  18. .gitattributes
  19. .gitignore
  20. .gn
  21. .style.yapf
  22. AUTHORS
  23. BUILD.gn
  24. CODE_OF_CONDUCT.md
  25. CONTRIBUTING.md
  26. LICENSE
  27. OWNERS
  28. PATENTS
  29. README.md
  30. rustfmt.toml
README.md

Fuchsia

Pink + Purple == Fuchsia (a new operating system)

What is Fuchsia?

Fuchsia is a modular, capability-based operating system. Fuchsia runs on modern 64-bit Intel and ARM processors.

Fuchsia is an open source project with a code of conduct that we expect everyone who interacts with the project to respect.

Read more about Fuchsia's principles.

How can I build and run Fuchsia?

See Getting Started.

Where can I learn more about Fuchsia?

See fuchsia.dev.