slog: add Level.MarshalJSON

Add a MarshalJSON method to Level so that it
marshals as a string.

This lets us remove special cases for Level in the handlers.

It also ensures that others who write handlers that output JSON will
get strings instead of numbers; the numbers are obscure,
uninformative, and could be confused with the values of other
level-numbering schemes.

Also, improve handler tests to check replacement.

Change-Id: Iedc7aa797469922fb9cfcc3b5d804806f3deb5d8
Run-TryBot: Jonathan Amsterdam <>
Reviewed-by: Alan Donovan <>
TryBot-Result: Gopher Robot <>
6 files changed
tree: 1855a72ffe3de39744e89429dec517b73e55b7bd
  1. apidiff/
  2. cmd/
  3. constraints/
  4. devtools/
  5. ebnf/
  6. ebnflint/
  7. errors/
  8. event/
  9. inotify/
  10. io/
  11. jsonrpc2/
  12. maps/
  13. mmap/
  14. rand/
  15. shiny/
  16. shootout/
  17. slices/
  18. slog/
  19. sumdb/
  20. typeparams/
  21. utf8string/
  22. .gitattributes
  23. .gitignore
  24. codereview.cfg
  26. go.mod
  27. go.sum



This subrepository holds experimental and deprecated (in the old directory) packages.

The idea for this subrepository originated as the pkg/exp directory of the main repository, but its presence there made it unavailable to users of the binary downloads of the Go installation. The subrepository has therefore been created to make it possible to go get these packages.

Warning: Packages here are experimental and unreliable. Some may one day be promoted to the main repository or other subrepository, or they may be modified arbitrarily or even disappear altogether.

In short, code in this subrepository is not subject to the Go 1 compatibility promise. (No subrepo is, but the promise is even more likely to be violated by go.exp than the others.)

Caveat emptor.