Strip fx call-chain noise from startup errors; clarify file:// error

internal/cli/app_test.go

@@ -0,0 +1,39 @@
+package cli
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestCleanStartupError(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "real fx error chain",
+			in:   `could not build arguments for function "sneak.berlin/go/vaultik/internal/cli".newSnapshotCreateCommand.func1.1 (/Users/user/dev/vaultik/internal/cli/snapshot.go:71): failed to build *vaultik.Vaultik: could not build arguments for function "sneak.berlin/go/vaultik/internal/vaultik".New (/Users/user/dev/vaultik/internal/vaultik/vaultik.go:59): failed to build storage.Storer: received non-nil error from function "sneak.berlin/go/vaultik/internal/storage".NewStorer (/Users/user/dev/vaultik/internal/storage/module.go:23): creating base path: mkdir /Volumes/BACKUPS: permission denied`,
+			want: `creating base path: mkdir /Volumes/BACKUPS: permission denied`,
+		},
+		{
+			name: "no fx wrapping",
+			in:   "plain error",
+			want: "plain error",
+		},
+		{
+			name: "single fx wrapping",
+			in:   `received non-nil error from function "foo" (file.go:1): underlying problem`,
+			want: "underlying problem",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := cleanStartupError(errors.New(tt.in)).Error()
+			if got != tt.want {
+				t.Errorf("got %q, want %q", got, tt.want)
+			}
+		})
+	}
+}