Files
sanderling/internal/verifier/verifier_test.go
T
pj 25e6725f91 fix(folio-spec): pick account card via seeded from(), not Math.random
Math.random() breaks --seed reproducibility. The verifier's seeded
RNG flows through from(), so re-running a seed now produces the
same card pick sequence.
2026-04-26 23:57:43 +07:00

336 lines
10 KiB
Go

package verifier
import (
"encoding/json"
"errors"
"math/rand/v2"
"strings"
"testing"
"github.com/priyanshujain/sanderling/internal/ltl"
)
func newVerifier(t *testing.T, options ...Option) *Verifier {
t.Helper()
verifier, err := New(options...)
if err != nil {
t.Fatal(err)
}
return verifier
}
func mustLoad(t *testing.T, verifier *Verifier, source string) {
t.Helper()
if err := verifier.Load(source); err != nil {
t.Fatalf("Load: %v", err)
}
}
const helloSpec = `
const screen = __sanderling__.extract(state => state.snapshots.screen ?? "");
const balance = __sanderling__.extract(state => state.snapshots["ledger.balance"] ?? 0);
globalThis.screen = screen;
globalThis.balance = balance;
globalThis.properties = {
balanceNonNegative: __sanderling__.always(() => balance.current >= 0),
};
globalThis.actions = __sanderling__.actions(() => [
__sanderling__.tap({ on: "id:home_button" }),
]);
`
func TestLoad_ExposesRuntimeBindings(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, helloSpec)
if len(verifier.extractors) != 2 {
t.Errorf("extractors registered: got %d, want 2", len(verifier.extractors))
}
if len(verifier.formulas) != 1 {
t.Errorf("formulas registered: got %d, want 1", len(verifier.formulas))
}
if _, ok := verifier.properties["balanceNonNegative"]; !ok {
t.Errorf("balanceNonNegative property missing: %+v", verifier.properties)
}
}
func TestPushSnapshot_UpdatesExtractorCurrentAndPrevious(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, helloSpec)
if err := verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{
"screen": json.RawMessage(`"customer_ledger"`),
"ledger.balance": json.RawMessage(`1500`),
}}); err != nil {
t.Fatal(err)
}
screenValue := verifier.runtime.GlobalObject().Get("screen").ToObject(verifier.runtime)
if screenValue.Get("current").String() != "customer_ledger" {
t.Errorf("screen.current wrong: %v", screenValue.Get("current"))
}
balanceValue := verifier.runtime.GlobalObject().Get("balance").ToObject(verifier.runtime)
if balanceValue.Get("current").ToInteger() != 1500 {
t.Errorf("balance.current wrong: %v", balanceValue.Get("current"))
}
// Push again: previous should mirror the prior current.
if err := verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{"ledger.balance": json.RawMessage(`2000`)}}); err != nil {
t.Fatal(err)
}
balanceValue = verifier.runtime.GlobalObject().Get("balance").ToObject(verifier.runtime)
if balanceValue.Get("previous").ToInteger() != 1500 {
t.Errorf("balance.previous wrong: %v", balanceValue.Get("previous"))
}
if balanceValue.Get("current").ToInteger() != 2000 {
t.Errorf("balance.current wrong: %v", balanceValue.Get("current"))
}
}
func TestEvaluateProperties_HoldsThenViolates(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, helloSpec)
cases := []struct {
balance int
want ltl.Verdict
}{
{1500, ltl.VerdictHolds},
{0, ltl.VerdictHolds},
{-1, ltl.VerdictViolated},
{500, ltl.VerdictViolated}, // sticky
}
for index, testCase := range cases {
raw, _ := json.Marshal(testCase.balance)
if err := verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{"ledger.balance": raw}}); err != nil {
t.Fatal(err)
}
verdicts := verifier.EvaluateProperties()
if got := verdicts["balanceNonNegative"]; got != testCase.want {
t.Errorf("step %d (balance=%d): got %v, want %v", index, testCase.balance, got, testCase.want)
}
}
}
func TestNextAction_FromActionsGenerator(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, helloSpec)
_ = verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{}})
action, err := verifier.NextAction()
if err != nil {
t.Fatal(err)
}
if action.Kind != ActionKindTap {
t.Errorf("kind: got %v, want Tap", action.Kind)
}
if action.On != "id:home_button" {
t.Errorf("selector: got %q, want id:home_button", action.On)
}
}
func TestNextAction_WeightedSelectsByWeight(t *testing.T) {
verifier := newVerifier(t, WithRand(rand.New(rand.NewPCG(42, 0))))
mustLoad(t, verifier, `
const tapHome = __sanderling__.actions(() => [__sanderling__.tap({ on: "id:home" })]);
const tapAway = __sanderling__.actions(() => [__sanderling__.tap({ on: "id:away" })]);
globalThis.actions = __sanderling__.weighted(
[1, tapHome],
[99, tapAway],
);
`)
_ = verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{}})
awayCount := 0
homeCount := 0
for range 200 {
action, err := verifier.NextAction()
if err != nil {
t.Fatal(err)
}
switch action.On {
case "id:home":
homeCount++
case "id:away":
awayCount++
}
}
if awayCount <= homeCount {
t.Errorf("expected away-skewed distribution, got home=%d away=%d", homeCount, awayCount)
}
}
func TestNextAction_EmptyGeneratorReturnsErrNoAction(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, `
globalThis.actions = __sanderling__.actions(() => []);
`)
_ = verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{}})
_, err := verifier.NextAction()
if !errors.Is(err, ErrNoAction) {
t.Errorf("expected ErrNoAction, got %v", err)
}
}
func TestInputText_RoundTrip(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, `
globalThis.actions = __sanderling__.actions(() => [
__sanderling__.inputText({ into: "id:phone", text: "+919876543210" }),
]);
`)
_ = verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{}})
action, err := verifier.NextAction()
if err != nil {
t.Fatal(err)
}
if action.Kind != ActionKindInputText {
t.Errorf("kind: %v", action.Kind)
}
if action.On != "id:phone" || action.Text != "+919876543210" {
t.Errorf("payload wrong: %+v", action)
}
}
func TestPushSnapshot_FeedsSnapshotsToExtractorState(t *testing.T) {
verifier := newVerifier(t)
mustLoad(t, verifier, `
globalThis.captured = __sanderling__.extract(state => state.snapshots["k"]);
`)
if err := verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{"k": json.RawMessage(`"hello"`)}}); err != nil {
t.Fatal(err)
}
value := verifier.runtime.GlobalObject().Get("captured").ToObject(verifier.runtime).Get("current")
if value.String() != "hello" {
t.Errorf("snapshot value not propagated: %v", value)
}
}
func TestLoad_PropagatesSyntaxError(t *testing.T) {
verifier := newVerifier(t)
err := verifier.Load(`const x = ;`)
if err == nil || !strings.Contains(err.Error(), "run spec") {
t.Errorf("expected run-spec error, got %v", err)
}
}
func TestEvaluateProperties_ThrowingPredicateDoesNotPanic(t *testing.T) {
const spec = `
globalThis.properties = {
broken: __sanderling__.always(() => { throw new Error("bad predicate"); }),
};
`
verifier := newVerifier(t)
mustLoad(t, verifier, spec)
if err := verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{}}); err != nil {
t.Fatal(err)
}
verdicts := verifier.EvaluateProperties()
if got := verdicts["broken"]; got != ltl.VerdictViolated {
t.Errorf("verdict: got %v, want %v", got, ltl.VerdictViolated)
}
predicateErr := verifier.PredicateError("broken")
if predicateErr == nil {
t.Fatal("PredicateError: got nil, want non-nil")
}
if !strings.Contains(predicateErr.Error(), "bad predicate") {
t.Errorf("PredicateError message: got %q, want to contain %q", predicateErr.Error(), "bad predicate")
}
}
func TestLoad_AcceptsSpecWithoutPropertiesOrActions(t *testing.T) {
verifier := newVerifier(t)
if err := verifier.Load(`const noop = 1;`); err != nil {
t.Fatal(err)
}
if got := verifier.EvaluateProperties(); len(got) != 0 {
t.Errorf("no properties expected, got %v", got)
}
if _, err := verifier.NextAction(); !errors.Is(err, ErrNoAction) {
t.Errorf("expected ErrNoAction, got %v", err)
}
}
// TestFrom_SeededReplayIsDeterministic guarantees `from()` over a per-step
// dynamic array picks the same element under the same seed across runs. The
// folio spec relies on this to replace Math.random() in account-card taps.
func TestFrom_SeededReplayIsDeterministic(t *testing.T) {
pickedSequence := func(seed uint64) []string {
verifier := newVerifier(t, WithRand(rand.New(rand.NewPCG(seed, 0))))
mustLoad(t, verifier, `
globalThis.actions = __sanderling__.actions(() => {
const cards = ["card_a", "card_b", "card_c", "card_d"];
return [__sanderling__.tap({ on: __sanderling__.from(cards).generate() })];
});
`)
_ = verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{}})
var picks []string
for range 20 {
action, err := verifier.NextAction()
if err != nil {
t.Fatal(err)
}
picks = append(picks, action.On)
}
return picks
}
first := pickedSequence(1234)
second := pickedSequence(1234)
for i := range first {
if first[i] != second[i] {
t.Fatalf("step %d: %q != %q (replay not deterministic)", i, first[i], second[i])
}
}
other := pickedSequence(5678)
identical := true
for i := range first {
if first[i] != other[i] {
identical = false
break
}
}
if identical {
t.Fatal("expected different seeds to produce different pick sequences")
}
}
// PredicateError must reflect the most recent step's predicate result, not a
// latched first-step error. The runner logs PredicateError once per step; if it
// stays pinned to step 1 forever, downstream debugging looks frozen even though
// the underlying state is changing.
func TestPredicateError_ReflectsCurrentStepNotFirstStep(t *testing.T) {
const spec = `
globalThis.counter = __sanderling__.extract(state => state.snapshots["count"]);
globalThis.properties = {
reportsCounter: __sanderling__.always(() => { throw new Error("count=" + counter.current); }),
};
`
verifier := newVerifier(t)
mustLoad(t, verifier, spec)
for step := 1; step <= 3; step++ {
raw := json.RawMessage([]byte{'"', byte('0' + step), '"'})
if err := verifier.PushSnapshot(SnapshotInput{Snapshots: Snapshots{"count": raw}}); err != nil {
t.Fatal(err)
}
_ = verifier.EvaluateProperties()
got := verifier.PredicateError("reportsCounter")
if got == nil {
t.Fatalf("step %d: PredicateError = nil, want non-nil", step)
}
want := "count=" + string(rune('0'+step))
if !strings.Contains(got.Error(), want) {
t.Errorf("step %d: PredicateError = %q, want to contain %q", step, got.Error(), want)
}
}
}