From d7036970e853489de0f81c0b26429833d178eef6 Mon Sep 17 00:00:00 2001
From: Sebastiaan van Stijn <github@gone.nl>
Date: Thu, 3 Sep 2026 21:49:09 +0200
Subject: [PATCH] cmd/docker-trust: fix tests

Some test-files were missing.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
---
 cmd/docker-trust/internal/test/cmd.go    | 81 ++++++++++++++++++++++++
 cmd/docker-trust/internal/test/writer.go | 25 ++++++++
 cmd/docker-trust/trust/inspect.go        |  2 +-
 3 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 cmd/docker-trust/internal/test/cmd.go
 create mode 100644 cmd/docker-trust/internal/test/writer.go

diff --git a/cmd/docker-trust/internal/test/cmd.go b/cmd/docker-trust/internal/test/cmd.go
new file mode 100644
index 0000000000..8b98d2df62
--- /dev/null
+++ b/cmd/docker-trust/internal/test/cmd.go
@@ -0,0 +1,81 @@
+package test
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/docker/cli/cli/streams"
+	"github.com/docker/cli/internal/prompt"
+	"github.com/spf13/cobra"
+	"gotest.tools/v3/assert"
+)
+
+func TerminatePrompt(ctx context.Context, t *testing.T, cmd *cobra.Command, cli *FakeCli) {
+	t.Helper()
+
+	errChan := make(chan error)
+	defer close(errChan)
+
+	// wrap the out stream to detect when the prompt is ready
+	writerHookChan := make(chan struct{})
+	defer close(writerHookChan)
+
+	outStream := streams.NewOut(NewWriterWithHook(cli.OutBuffer(), func(p []byte) {
+		writerHookChan <- struct{}{}
+	}))
+	cli.SetOut(outStream)
+
+	r, _, err := os.Pipe()
+	assert.NilError(t, err)
+	cli.SetIn(streams.NewIn(r))
+
+	notifyCtx, notifyCancel := context.WithCancel(ctx)
+	t.Cleanup(notifyCancel)
+
+	go func() {
+		errChan <- cmd.ExecuteContext(notifyCtx)
+	}()
+
+	writeCtx, writeCancel := context.WithTimeout(ctx, 100*time.Millisecond)
+	defer writeCancel()
+
+	// wait for the prompt to be ready
+	select {
+	case <-writeCtx.Done():
+		t.Fatalf("command %s did not write prompt to stdout", cmd.Name())
+	case <-writerHookChan:
+		// drain the channel for future buffer writes
+		go func() {
+			for {
+				select {
+				case <-ctx.Done():
+					return
+				case <-writerHookChan:
+				}
+			}
+		}()
+	}
+
+	assert.Check(t, cli.OutBuffer().Len() > 0)
+
+	// a small delay to ensure the plugin is prompting
+	time.Sleep(100 * time.Microsecond)
+
+	errCtx, errCancel := context.WithTimeout(ctx, 100*time.Millisecond)
+	defer errCancel()
+
+	// sigint and sigterm are caught by the prompt
+	// this allows us to gracefully exit the prompt with a 0 exit code
+	notifyCancel()
+
+	select {
+	case <-errCtx.Done():
+		t.Logf("command stdout:\n%s\n", cli.OutBuffer().String())
+		t.Logf("command stderr:\n%s\n", cli.ErrBuffer().String())
+		t.Fatalf("command %s did not return after SIGINT", cmd.Name())
+	case err := <-errChan:
+		assert.ErrorIs(t, err, prompt.ErrTerminated)
+	}
+}
diff --git a/cmd/docker-trust/internal/test/writer.go b/cmd/docker-trust/internal/test/writer.go
new file mode 100644
index 0000000000..3d922fb57a
--- /dev/null
+++ b/cmd/docker-trust/internal/test/writer.go
@@ -0,0 +1,25 @@
+package test
+
+import (
+	"io"
+)
+
+type writerWithHook struct {
+	actualWriter io.Writer
+	hook         func([]byte)
+}
+
+func (w *writerWithHook) Write(p []byte) (n int, err error) {
+	defer w.hook(p)
+	return w.actualWriter.Write(p)
+}
+
+var _ io.Writer = (*writerWithHook)(nil)
+
+// NewWriterWithHook returns a io.Writer that still
+// writes to the actualWriter but also calls the hook function
+// after every write. It is useful to use this function when
+// you need to wait for a writer to complete writing inside a test.
+func NewWriterWithHook(actualWriter io.Writer, hook func([]byte)) *writerWithHook {
+	return &writerWithHook{actualWriter: actualWriter, hook: hook}
+}
diff --git a/cmd/docker-trust/trust/inspect.go b/cmd/docker-trust/trust/inspect.go
index 74240b61ad..fe16121ce7 100644
--- a/cmd/docker-trust/trust/inspect.go
+++ b/cmd/docker-trust/trust/inspect.go
@@ -81,7 +81,7 @@ func getRepoTrustInfo(ctx context.Context, dockerCLI command.Cli, remote string)
 		}
 	}
 
-	var signerList []trustSigner
+	signerList := []trustSigner{}
 	for signerName, signerKeys := range getDelegationRoleToKeyMap(delegationRoles) {
 		signerKeyList := make([]trustKey, 0, len(signerKeys))
 		for _, keyID := range signerKeys {