test: cover worktree disk pressure gate (#840)

Co-authored-by: homeboy-ci[bot] <266378653+homeboy-ci[bot]@users.noreply.github.com>

Author: chubes4

tests/worktree-add-lifecycle.php

@@ -42,7 +42,13 @@ function is_wp_error( mixed $value ): bool {
 	return $value instanceof WP_Error;
 }
 
+$GLOBALS['datamachine_code_test_filters'] = array();
 function apply_filters( string $hook_name, mixed $value, mixed ...$args ): mixed {
+	$callback = $GLOBALS['datamachine_code_test_filters'][ $hook_name ] ?? null;
+	if ( is_callable($callback) ) {
+		return $callback($value, ...$args);
+	}
+
 	return $value;
 }
 
@@ -232,10 +238,31 @@ function create_primary_checkout( string $workspace_root ): void {
 	$GLOBALS['wpdb'] = $wpdb;
 
 	$workspace = new Workspace();
+	$GLOBALS['datamachine_code_test_filters']['datamachine_worktree_disk_budget_thresholds'] = static function ( array $thresholds ) use ( $workspace_root ): array {
+		$free = disk_free_space($workspace_root);
+		assert_true(false !== $free, 'fixture workspace free space is not measurable');
+		$thresholds['refuse_free_bytes']   = (int) $free + 1;
+		$thresholds['warn_free_bytes']     = (int) $free + 1;
+		$thresholds['refuse_free_percent'] = 0.0;
+		$thresholds['warn_free_percent']   = 0.0;
+		return $thresholds;
+	};
+	$refused = $workspace->worktree_add('homeboy', 'audit-primitives-disk-refused', 'origin/main', false, false, false, false, false);
+	unset($GLOBALS['datamachine_code_test_filters']['datamachine_worktree_disk_budget_thresholds']);
+	assert_true(is_wp_error($refused), 'disk pressure below the hard floor reported success');
+	assert_true('worktree_disk_budget_exceeded' === $refused->get_error_code(), 'unexpected disk pressure refusal error code');
+	$refusal_data = (array) $refused->get_error_data();
+	$disk_budget  = (array) ( $refusal_data['disk_budget'] ?? array() );
+	assert_true('refused' === ( $disk_budget['status'] ?? '' ), 'disk pressure refusal did not include refused budget status');
+	assert_true(isset($disk_budget['free_bytes'], $disk_budget['effective_refuse_bytes']), 'disk pressure refusal must include exact free and required bytes');
+	assert_true(str_contains($refused->get_error_message(), 'studio wp datamachine-code workspace worktree bounded-cleanup-eligible-apply --dry-run --limit=25'), 'disk pressure refusal must include the next cleanup command');
+	assert_true(! is_dir($workspace_root . '/homeboy@audit-primitives-disk-refused'), 'disk pressure refusal left a worktree directory behind');
+
 	$result    = $workspace->worktree_add('homeboy', 'audit-primitives-20260616', 'origin/main', false, false, false, false, true);
 	assert_true(! is_wp_error($result), is_wp_error($result) ? $result->get_error_message() : 'worktree_add failed');
 	assert_true(is_dir($result['path']), 'successful worktree_add path is not accessible');
 	assert_true(isset($wpdb->rows['homeboy@audit-primitives-20260616']), 'successful worktree_add was not persisted');
+	assert_true('refused' !== ( $result['disk_budget']['status'] ?? '' ), 'normal worktree_add should pass the disk budget gate without hard refusal');
 
 	$show = $workspace->show_repo('homeboy@audit-primitives-20260616');
 	assert_true(! is_wp_error($show), 'persisted worktree is not visible to show_repo');

tests/worktree-disk-budget.php

@@ -50,6 +50,25 @@ function assert_true( bool $condition, string $message ): void {
 	assert_true('studio wp datamachine-code workspace worktree bounded-cleanup-eligible-apply --limit=25' === $bounded['apply_command'], 'bounded cleanup apply command is missing');
 	assert_true(str_contains($bounded['apply_note'], 'may skip rows'), 'bounded cleanup apply note must explain dirty/unpushed revalidation can block removal');
 
+	$healthy = WorktreeDiskBudget::evaluate(
+		array(
+			'workspace_path' => '/tmp/dmc-test-workspace',
+			'free_bytes'     => 40 * $gib,
+			'total_bytes'    => 100 * $gib,
+			'worktree_count' => 12,
+		),
+		array(
+			'warn_free_bytes'     => 20 * $gib,
+			'refuse_free_bytes'   => 10 * $gib,
+			'warn_free_percent'   => 15.0,
+			'refuse_free_percent' => 10.0,
+			'warn_worktree_count' => 100,
+		)
+	);
+
+	assert_true('ok' === $healthy['status'], 'healthy free space should pass the worktree disk budget gate');
+	assert_true(array() === $healthy['warnings'], 'healthy free space should not emit disk budget warnings');
+
 	fwrite(STDOUT, "worktree-disk-budget ok\n");
 } catch (Throwable $e) {
 	fwrite(STDERR, $e->getMessage() . "\n");