Agent eval assertions

<?php
require 'examples/boot.php';

use Cognesy\Agents\Builder\AgentBuilder;
use Cognesy\Agents\Capability\Core\UseDriver;
use Cognesy\Agents\Drivers\Testing\FakeAgentDriver;
use Cognesy\Agents\Evals\EvalContext;
use Cognesy\Agents\Evals\LocalAgentTarget;

$target = LocalAgentTarget::fromFactory(static fn() => AgentBuilder::base()
    ->withCapability(new UseDriver(FakeAgentDriver::fromResponses('Verification is required for A1049.')))
    ->build());

// EvalContext collects every check so the report can show all evidence, not only the first failure.
$t = new EvalContext($target);

// Execute the agent first; subsequent assertions inspect this captured run.
$t->send('Refund A1049.');

// Require the agent loop to finish successfully.
$t->succeeded();

// These intentionally overlap to demonstrate three levels of tool-use policy:
// forbid one dangerous tool, forbid all tools, and enforce a numeric tool-call budget.
$t->notCalledTool('refunds_issue');
$t->usedNoTools();
$t->maxToolCalls(0);

// Require both tool executions and the overall agent run to be free of errors.
$t->noFailedActions();

// Start fluent assertions against the captured reply value.
$t->expect($t->run()->reply())
    // `includes` and `matches` are gating checks: either failure makes the eval fail.
    ->includes('Verification')
    ->matches('/A1049/')
    // Similarity produces a 0..1 score. The following modifiers affect only this last check.
    ->similarity('Verification is required for A1049.')
    // Similarity is soft by default; this makes the non-gating policy explicit.
    ->soft()
    // Pass this scored check when normalized text similarity is at least 0.90.
    ->atLeast(0.9);

echo "Observed trajectory: status=completed tools={$t->run()->tools()->count()} errors=0\n";
echo "Collected evidence:\n";
$passed = 0;
foreach ($t->assertions() as $result) {
    $status = $result->passed() ? 'PASS' : 'FAIL';
    echo "- {$status} [{$result->severity()->value}] {$result->name()}";
    echo ' score=' . number_format($result->score(), 2) . "\n";
    if (!$result->passed()) {
        throw new RuntimeException("Assertion {$result->name()} did not pass.");
    }
    $passed++;
}
echo "Result: {$passed}/{$t->assertions()->count()} checks passed; gates and soft scores remain visible together.\n";
?>