[sujal-maheshwari2004]

What was wrong

• promptctl diff always exited 0, so CI had to grep the output for => structural to gate a change.
• A prompt added since the ref was diffed against an empty file and reported as structural instead of new.

The fix

• New flag -fail-on (also --fail-on): a comma-separated list of verdicts (new, structural, tweak, minor). diff still prints the full diff, then exits 1 if any prompt's verdict is in the list and names the matching prompts on stderr. Without the flag the exit code stays 0 (backward compatible). An unknown verdict name exits 2, like other flag errors.
• A prompt that isn't in the ref now prints new prompt (not in <ref>) / => new instead of a fake insert hunk that always reads structural.
• Flags can come before or after the ref (promptctl diff origin/main -fail-on structural).
• The diff loop moved into runDiff, which returns each prompt's verdict (semdiff.Worst of its hunks), so it can be tested in-process.

Tests

New cmd/promptctl/diff_test.go: TestRunDiffVerdicts (real go-git repo: a rewrite reads structural, an added prompt reads new), TestRunDiffNoChanges, and TestParseFailOn.

With the new branch disabled, the test fails as on main:

--- FAIL: TestRunDiffVerdicts (0.26s)
    diff_test.go:62: runDiff = [{acme/support/added.prompt structural} {acme/support/agent.prompt structural}], want [{acme/support/added.prompt new} {acme/support/agent.prompt structural}]

Full suite: GOWORK=off go build ./... && go vet ./... && go test ./... → ok github.com/priompt/cli/cmd/promptctl

Before / after (real run, offline lexical embedder)

Repo with one committed prompt rewritten and one new prompt.

Before (main):

## acme/support/new.prompt
change @ new lines 1-1 (old 1-0): insert
  Signal 2 (point delta): 1.000
  ...
  => structural
exit=0
$ promptctl diff -fail-on structural
unknown ref "-fail-on": reference not found
exit=1

After:

## acme/support/agent.prompt
...
  => structural

## acme/support/new.prompt
new prompt (not in HEAD)
  => new

exit=0
$ promptctl diff -fail-on structural
diff: 1 prompt(s) match -fail-on structural: acme/support/agent.prompt (structural)
exit=1
$ promptctl diff HEAD --fail-on new
diff: 1 prompt(s) match -fail-on new: acme/support/new.prompt (new)
exit=1
$ promptctl diff -fail-on bogus
-fail-on: unknown verdict "bogus" (want new, structural, tweak, minor)
usage: promptctl diff [-fail-on verdicts] [ref]
exit=2

Fixes #3

🤖 Generated with Claude Code