CLI --reporter

chef commands accept the --reporter <name> option to switch output format. Available reporters:

• default — human-readable output (used when nothing is passed).
• json — structured JSON to stdout. Format is documented in Response format.
• teamcity — TeamCity service messages, only for chef test.

chef build main.core --reporter json
chef lint 'ui.*' --reporter json
chef test main.core --reporter json
chef typecheck main.core --reporter json
chef diag top-used --limit 10 --reporter json
chef diag circular-deps --reporter json

When to use json

• You already have a shell-based pipeline — adding --reporter json is easier than parsing human output.
• You need to feed results into another tool (jq, dashboard, Slack notifier).
• You want to diff results between runs — JSON diffs cleanly.

Supported commands

Command	--reporter json
chef build	✓
chef lint	✓
chef test	✓
chef typecheck	✓
chef diag top-used	✓
chef diag top-deps	✓
chef diag top-deps-tree	✓
chef diag top-bundle-size	✓
chef diag top-total-size	✓
chef diag config	✓
chef diag unused-deps	✓
chef diag unused	✓
chef diag circular-deps	✓
chef diag circular-imports	✓
chef diag find-usages	✓
chef diag find-loaders	✓
chef diag deps-tree	✓
chef diag bundle-size	✓
chef diag baseline	not yet
chef create, init, aliases	not needed in CI

Exit codes

• 0 — success: true
• 1 — success: false (build/lint/test errors)
• 2 — incompatible flags (e.g. --watch with --reporter json)

Incompatible flags

--watch is incompatible with --reporter json — watch mode implies a continuous stream, which doesn't fit a one-shot JSON document.

$ chef build main.core --watch --reporter json
{ "success": false, "command": "build", "error": { "code": "CF2001", "message": "--watch is not supported with --reporter json" }, ... }
$ echo $?
2

What ends up in stdout

In --reporter json mode stdout contains only JSON. All human-readable output (greetings, progress bars, tables) is suppressed so the output can be piped straight into a parser. If you ever see anything else there, that's a bug — please file an issue.

Stderr stays free for unexpected Node.js crash dumps; under normal operation it's silent too.

Examples

Pipe into jq

chef diag top-bundle-size --limit 5 --reporter json | jq '.data.results[] | {name, total}'

Fail the pipeline on errors

chef build 'ui.*' --reporter json | jq -e '.success' > /dev/null \
  || { echo 'Build failed'; exit 1; }

Extract failed extension names

chef lint 'ui.*' --reporter json \
  | jq -r '.extensions[] | select(.success == false) | .name'

Read a specific bundle size

chef build main.core --reporter json | jq '.extensions[0].details.bundles[0].size'

List failing tests with file:line

chef test 'ui.*' --reporter json \
  | jq -r '.extensions[].errors[] | "\(.file):\(.line)  \(.message)"'

Reporter teamcity

For chef test only. Instead of JSON it prints TeamCity service messages (##teamcity[testStarted ...]). Used in TeamCity CI.

chef test main.core --reporter teamcity