Show configuration findings when processing cannot start

internal/cli/process_command_integration_test.go

@@ -3,14 +3,50 @@ package cli
 import (
 	"bytes"
 	"context"
+	"errors"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
 	commandkit "go.maximumdirect.net/commandkit"
+	ck "go.maximumdirect.net/configkit"
 )
 
+func TestProcessShowsConfigurationLoadDiagnostics(t *testing.T) {
+	app, err := buildApplication()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, tc := range []struct {
+		name, config, finding string
+	}{
+		{"obsolete version", "version: 2\n", "docs/migrations/v3.md"},
+		{"invalid retry budget", "version: 3\nllm: {transient_retries: -1}\n", "retry budget must be non-negative"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			dir := t.TempDir()
+			configPath := filepath.Join(dir, "config.yml")
+			if err := os.WriteFile(configPath, []byte(tc.config), 0600); err != nil {
+				t.Fatal(err)
+			}
+			output := filepath.Join(dir, "out.json")
+			var out, stderr bytes.Buffer
+			args := []string{"process", "--quiet", "--config", configPath, "--output", output, filepath.Join(dir, "transcript.json")}
+			result := app.Execute(context.Background(), args, commandkit.Streams{Out: &out, Err: &stderr})
+			var loadErr *ck.LoadError
+			if result.Status != 2 || !errors.As(result.Cause, &loadErr) || out.Len() != 0 ||
+				!strings.Contains(stderr.String(), tc.finding) || !strings.Contains(stderr.String(), configPath) {
+				t.Fatalf("status=%d cause=%v out=%q err=%q", result.Status, result.Cause, out.String(), stderr.String())
+			}
+			entries, err := os.ReadDir(dir)
+			if err != nil || len(entries) != 1 {
+				t.Fatalf("outputs created on load failure: %v, err=%v", entries, err)
+			}
+		})
+	}
+}
+
 func TestProcessUsesResolvedReportingMode(t *testing.T) {
 	dir := t.TempDir()
 	for name, contents := range map[string]string{