feat: add JSON output to taskrun delete

[Debashich]

Closes #2850

Changes

Add --output json/yaml (-o) structured output support to tkn taskrun delete.

When specified, the command returns machine-readable output in JSON or YAML format. Using -o json or -o yaml skips the interactive confirmation prompt, allowing non-interactive usage.

Example:

$ tkn taskrun delete foo bar -n ns -o json
{
    "deleted": [
        "foo",
        "bar"
    ]
}

$ tkn taskrun delete foo -n ns -o yaml
deleted:
- foo

• Supports both JSON and YAML output formats.
• Uses the shared structured-output formatter for consistent output.
• Preserves safeguards around TaskRuns associated with running PipelineRuns.
• Includes tests for structured output and deletion behavior.

Submitter Checklist

• Includes tests for the functionality added.
• Run the code checkers with make check.
• Regenerate the manpages, docs and Go formatting with make generated.
• Commit messages follow [commit message best practices](https://github.com/tektoncd/community/blob/master/standards.md#commit-messages).

See [the contribution guide](https://github.com/tektoncd/cli/blob/master/CONTRIBUTING.md) for more details.

Release Notes

Add --output json/yaml support to taskrun delete.
Using -o skips the confirmation prompt.

[tekton-robot]

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[Copilot]

Pull request overview

This PR adds -o/--output json support to tkn taskrun delete, enabling machine-readable output of deleted TaskRuns and extending the shared pkg/deleter helper with accessors for successful deletions (plus unit tests).

Changes:

• Added JSON output path for taskrun delete, and suppressed interactive confirmation when JSON is requested.
• Extended pkg/deleter with accessors for successful deletes / related deletes.
• Added unit tests for the new deleter accessors and JSON output for taskrun delete.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 7 comments.

File	Description
pkg/deleter/deleter.go	Adds accessors for successful deletes and successful related deletes.
pkg/deleter/deleter_test.go	Adds unit tests validating the new deleter accessors.
pkg/cmd/taskrun/delete.go	Implements JSON output mode and adjusts delete flow to suppress prompts in JSON mode.
pkg/cmd/taskrun/delete_test.go	Adds tests asserting JSON output for taskrun delete.

Suppressed comments (1)

pkg/deleter/deleter.go:113

• SuccessfulRelatedDeletes also returns the backing slice directly, which allows external mutation of Deleter state. Returning a copy prevents subtle bugs when callers append/modify the returned slice.

func (d *Deleter) SuccessfulRelatedDeletes() []string {
	return d.successfulRelatedDeletes
}

---

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

Suppressed comments (5)

pkg/cmd/taskrun/delete.go:135

• JSON mode skips CheckOptions entirely, but that method performs validation before prompting. As a result, -o json accepts invalid destructive combinations such as named TaskRuns with --all/--keep, and even an invocation with neither names nor --all succeeds with an empty result. Keep the validation and suppress only the confirmation prompt.

			if output != "json" {
				if err := opts.CheckOptions(s, availableTrs, p.Namespace()); err != nil {
					return err
				}
			}

pkg/cmd/taskrun/delete.go:190

• With --force -o json, a TaskRun owned by a running PipelineRun writes this warning to stdout before the JSON document, making stdout invalid JSON. Send the warning to stderr so stdout remains machine-readable.

			if !prFinished && !opts.ForceDelete && output != "json" {

pkg/cmd/taskrun/delete.go:240

• This returns success immediately after encoding and drops any deletion errors accumulated by Deleter. A delete that fails after lookup (for example, due to a race or API error) is therefore reported as a successful command with only the failed name omitted; encode the result, then return d.Errors().

		return json.NewEncoder(s.Out).Encode(result)

pkg/cmd/taskrun/delete.go:233

• The JSON branch is unreachable for the two no-op --task --keep cases above because they return after printing human-readable status text. For example, when --keep equals the number of matching TaskRuns, -o json does not produce JSON at all. Route those early exits through the JSON renderer and return an empty deleted array.

	if output == "json" {

pkg/cmd/taskrun/delete.go:237

• The --task deletion path records deleted TaskRun names in successfulRelatedDeletes, so this field becomes null even when TaskRuns were successfully deleted. Include both direct and related successes in the JSON result.

			Deleted: d.SuccessfulDeletes(),

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

Suppressed comments (1)

pkg/cmd/taskrun/delete.go:243

• In -o json mode this function currently returns after encoding JSON, so any accumulated deletion errors from d.Errors() are dropped (command can exit 0 even when deletes failed). Also, some early returns in the --task/--keep paths print human output and bypass JSON entirely, and when nothing is deleted the current slice construction can encode as null instead of []. Consider (1) emitting JSON for the early-return paths, (2) always encoding an empty array when nothing was deleted, and (3) returning d.Errors() after successfully writing JSON.

	if output == "json" {
		result := struct {
			Deleted []string `json:"deleted"`
		}{
			Deleted: append(append([]string(nil), d.SuccessfulRelatedDeletes()...), d.SuccessfulDeletes()...),

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

Suppressed comments (1)

pkg/cmd/taskrun/delete.go:246

• When neither accessor contains an item, these nested appends preserve a nil slice, so encoding/json emits {"deleted":null} rather than the {"deleted":[]} contract asserted by the new no-op test. Initialize the accumulation with a non-nil empty slice so no-op deletions still produce an array.

			Deleted: append(append([]string(nil), d.SuccessfulRelatedDeletes()...), d.SuccessfulDeletes()...),

[divyansh42]

@Debashich do you have any updates on this PR?

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[divyansh42]

@Debashich could you please add release notes in the PR description and also add a sample output.

[divyansh42]

/retest

[Copilot]

🟡 Changes recommended

The CLI advertises several output formats while the implementation accepts only JSON.

Get a fresh assessment by requesting another Copilot review.

Review details

• Files reviewed: 4/4 changed files
• Comments generated: 1
• Review effort level: Balanced

[Debashich]

@divyansh42 Quick update on what happened after your requested changes:

I implemented all 3 review changes, added the release note + sample output, removed the generic output flags so only json is advertised, ran gofmt, regenerated the docs, and pushed the updated commit.

During testing, one existing TaskRun delete unit test was failing due to a fixture/expected-output mismatch. I reproduced the same failure on the base branch, so I confirmed it wasn't caused by this PR, then fixed the test fixture and amended the commit.

After the latest push, build, lint, unit tests, generated code, multi-arch, CodeQL and k8s-plus-one E2E are passing. The only remaining failure is k8s-oldest E2E.

I checked the full E2E logs, and the failure is actually TestPipelineInteractiveStartE2E, which times out after 10 minutes in the go-expect interactive test path. The PipelineRun itself starts successfully before the test hangs. The TaskRun/Pipeline deletion E2Es are passing.

So I haven't changed anything in the E2E tests/infrastructure since the remaining failure appears unrelated to this PR.

[pratap0007]

/retest

[pratap0007]

@Debashich Could you please add support for the -o yaml format as well? We are adding support for both -o yaml and -o json to the other commands for consistency.

[divyansh42]

@Debashich a recent PR #3318 has been merged, which covers other commands.
Could you please refer to the same and rebase your PR? Thanks!

[Debashich]

@divyansh42 @pratap0007 I've made the requested changes, added validation for unsupported output formats, and updated the docs for JSON/YAML output. Everything is pushed now. Could you take another look when you get a chance? Thanks!