Isolate pipeline configuration discovery

internal/app/pipeline_config_path_test.go

@@ -1,10 +1,16 @@
 package app
 
 import (
+	"bytes"
+	"context"
+	"errors"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
+
+	configkit "gitea.maximumdirect.net/eric/ConfigKit"
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
 )
 
 func TestResolvePipelineConfigPathWithCandidatesExplicitWins(t *testing.T) {
@@ -55,11 +61,57 @@ func TestResolvePipelineConfigPathWithCandidatesPrecedence(t *testing.T) {
 }
 
 func TestResolvePipelineConfigPathWithCandidatesMissing(t *testing.T) {
-	_, err := resolvePipelineConfigPathWithCandidates("", []string{"/does/not/exist/one.yml", "/does/not/exist/two.yml"})
+	directory := t.TempDir()
+	first := filepath.Join(directory, "one.yml")
+	second := filepath.Join(directory, "two.yml")
+	_, err := resolvePipelineConfigPathWithCandidates("", []string{first, second})
 	if err == nil {
 		t.Fatal("expected error, got nil")
 	}
 	if !strings.Contains(err.Error(), "no default pipeline config found") {
 		t.Fatalf("error = %q, want missing-defaults context", err.Error())
 	}
+	if !strings.Contains(err.Error(), first) || !strings.Contains(err.Error(), second) {
+		t.Fatalf("error = %q, want controlled searched paths", err.Error())
+	}
+}
+
+func TestExecuteMissingExplicitConfigDiscoversExistingDefaultBeforeLoading(t *testing.T) {
+	directory := t.TempDir()
+	missing := filepath.Join(directory, "missing.yml")
+	existing := filepath.Join(directory, "pipeline.yml")
+	if err := os.WriteFile(existing, []byte("workspace:\n  root: ./tmp\n"), 0o644); err != nil {
+		t.Fatalf("write default pipeline: %v", err)
+	}
+
+	controlledErr := errors.New("controlled pipeline loader boundary")
+	loadedPath := ""
+	deps := commandDependenciesForPipelineCandidates(missing, existing)
+	deps.loadPipelineConfig = func(path string, _ config.PipelineLoadOptions) (*config.PipelineConfig, error) {
+		loadedPath = path
+		return nil, controlledErr
+	}
+	deps.loadSecretsDir = func(string) (*configkit.SecretsReport, error) {
+		t.Fatal("absent conventional secrets directory unexpectedly invoked bootstrap loader")
+		return nil, nil
+	}
+
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	code := executeWithDependencies([]string{"config", "validate"}, &stdout, &stderr, deps, func(context.Context, *config.Config, BoundedPlan, RunOptions) (*RunSummary, error) {
+		t.Fatal("config validation unexpectedly invoked pipeline executor")
+		return nil, nil
+	})
+	if code == 0 {
+		t.Fatal("exit code = 0, want controlled loader failure")
+	}
+	if loadedPath != existing {
+		t.Fatalf("loader path = %q, want discovered default %q", loadedPath, existing)
+	}
+	if stdout.Len() != 0 {
+		t.Fatalf("stdout = %q, want empty", stdout.String())
+	}
+	if !strings.Contains(stderr.String(), controlledErr.Error()) {
+		t.Fatalf("stderr = %q, want controlled loader error", stderr.String())
+	}
 }