Ensure at least one trigger is present and triggers are followed by actions

[MAILPOET-4700]

mailpoet/lib/Automation/Engine/Validation/WorkflowRules/AtLeastOneTriggerRule.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace MailPoet\Automation\Engine\Validation\WorkflowRules;
+
+use MailPoet\Automation\Engine\Data\Workflow;
+use MailPoet\Automation\Engine\Exceptions;
+use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowNode;
+use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowNodeVisitor;
+
+class AtLeastOneTriggerRule implements WorkflowNodeVisitor {
+  public const RULE_ID = 'at-least-one-trigger';
+
+  public function initialize(Workflow $workflow): void {
+    foreach ($workflow->getSteps() as $step) {
+      if ($step->getType() === 'trigger') {
+        return;
+      }
+    }
+
+    throw Exceptions::workflowStructureNotValid(__('There must be at least one trigger in the workflow.', 'mailpoet'), self::RULE_ID);
+  }
+
+  public function visitNode(Workflow $workflow, WorkflowNode $node): void {
+  }
+
+  public function complete(Workflow $workflow): void {
+  }
+}

mailpoet/lib/Automation/Engine/Validation/WorkflowRules/TriggerNeedsToBeFollowedByActionRule.php

@@ -0,0 +1,37 @@
+<?php declare(strict_types = 1);
+
+namespace MailPoet\Automation\Engine\Validation\WorkflowRules;
+
+use MailPoet\Automation\Engine\Data\Step;
+use MailPoet\Automation\Engine\Data\Workflow;
+use MailPoet\Automation\Engine\Exceptions;
+use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowNode;
+use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowNodeVisitor;
+
+class TriggerNeedsToBeFollowedByActionRule implements WorkflowNodeVisitor {
+  public const RULE_ID = 'trigger-needs-to-be-followed-by-action';
+
+  public function initialize(Workflow $workflow): void {
+  }
+
+  public function visitNode(Workflow $workflow, WorkflowNode $node): void {
+    $step = $node->getStep();
+    if ($step->getType() !== Step::TYPE_TRIGGER) {
+      return;
+    }
+    $nextSteps = $step->getNextSteps();
+    if (!count($nextSteps)) {
+      throw Exceptions::workflowStructureNotValid(__('A trigger needs to be followed by an action.', 'mailpoet'), self::RULE_ID);
+    }
+    foreach ($nextSteps as $step) {
+      $step = $workflow->getStep($step->getId());
+      if ($step && $step->getType() === Step::TYPE_ACTION) {
+        continue;
+      }
+      throw Exceptions::workflowStructureNotValid(__('A trigger needs to be followed by an action.', 'mailpoet'), self::RULE_ID);
+    }
+  }
+
+  public function complete(Workflow $workflow): void {
+  }
+}

mailpoet/lib/Automation/Engine/Validation/WorkflowValidator.php

@@ -4,12 +4,14 @@ namespace MailPoet\Automation\Engine\Validation;
 
 use MailPoet\Automation\Engine\Data\Workflow;
 use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowWalker;
+use MailPoet\Automation\Engine\Validation\WorkflowRules\AtLeastOneTriggerRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\ConsistentStepMapRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\NoCycleRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\NoDuplicateEdgesRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\NoJoinRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\NoSplitRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\NoUnreachableStepsRule;
+use MailPoet\Automation\Engine\Validation\WorkflowRules\TriggerNeedsToBeFollowedByActionRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\TriggersUnderRootRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\UnknownStepRule;
 use MailPoet\Automation\Engine\Validation\WorkflowRules\ValidStepArgsRule;
@@ -53,6 +55,8 @@ class WorkflowValidator {
       new ConsistentStepMapRule(),
       new NoDuplicateEdgesRule(),
       new TriggersUnderRootRule(),
+      new AtLeastOneTriggerRule(),
+      new TriggerNeedsToBeFollowedByActionRule(),
       new NoCycleRule(),
       new NoJoinRule(),
       new NoSplitRule(),

mailpoet/tests/unit/Automation/Engine/Validation/WorkflowRules/AtLeastOnTriggerTest.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace MailPoet\Automation\Engine\Validation\WorkflowRules;
+
+use MailPoet\Automation\Engine\Data\Step;
+use MailPoet\Automation\Engine\Data\Workflow;
+use MailPoet\Automation\Engine\Exceptions\UnexpectedValueException;
+use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowWalker;
+
+require_once __DIR__ . '/WorkflowRuleTest.php';
+
+class AtLeastOnTriggerTest extends WorkflowRuleTest
+{
+  public function testItPassesWhenTriggerExists(): void {
+    $steps = [
+      'root' => $this->createStep('root', Step::TYPE_ROOT, ['t']),
+      't' => $this->createStep('t', Step::TYPE_TRIGGER),
+    ];
+    $workflow = $this->make(Workflow::class, ['getSteps' => $steps, 'getStep' => function($id) use ($steps) { return $steps[$id]??null; }]);
+
+    (new WorkflowWalker())->walk($workflow, [new AtLeastOneTriggerRule()]);
+    //no exception thrown.
+  }
+
+  public function testItFailsWhenNoTriggerExists(): void {
+    $steps = [
+      'root' => $this->createStep('root', Step::TYPE_ROOT)
+    ];
+    $workflow = $this->make(Workflow::class, ['getSteps' => $steps, 'getStep' => function($id) use ($steps) { return $steps[$id]??null; }]);
+
+
+    $this->expectException(UnexpectedValueException::class);
+    $this->expectExceptionMessage('Invalid workflow structure: There must be at least one trigger in the workflow.');
+    (new WorkflowWalker())->walk($workflow, [new AtLeastOneTriggerRule()]);
+  }
+}

mailpoet/tests/unit/Automation/Engine/Validation/WorkflowRules/TriggerNeedsNextStepsRuleTest.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace MailPoet\Automation\Engine\Validation\WorkflowRules;
+
+require_once __DIR__ . '/WorkflowRuleTest.php';
+
+use MailPoet\Automation\Engine\Data\Step;
+use MailPoet\Automation\Engine\Data\Workflow;
+use MailPoet\Automation\Engine\Exceptions\UnexpectedValueException;
+use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowWalker;
+
+class TriggerNeedsNextStepsRuleTest extends WorkflowRuleTest
+{
+  public function testItPassesWhenActionFollows(): void {
+    $steps = [
+      'root' => $this->createStep('root', Step::TYPE_ROOT, ['t']),
+      't' => $this->createStep('t', Step::TYPE_TRIGGER, ['a']),
+      'a' => $this->createStep('a', Step::TYPE_ACTION, []),
+    ];
+    $workflow = $this->make(Workflow::class, ['getSteps' => $steps, 'getStep' => function($id) use ($steps) { return $steps[$id]??null; }]);
+
+    (new WorkflowWalker())->walk($workflow, [new TriggerNeedsToBeFollowedByActionRule()]);
+    //no exception thrown.
+  }
+
+  public function testItFailsWhenNoActionIsFollowed(): void {
+    $steps = [
+      'root' => $this->createStep('root', Step::TYPE_ROOT, ['t']),
+      't' => $this->createStep('t', Step::TYPE_TRIGGER, []),
+    ];
+    $workflow = $this->make(Workflow::class, ['getSteps' => $steps, 'getStep' => function($id) use ($steps) { return $steps[$id]??null; }]);
+
+    $this->expectException(UnexpectedValueException::class);
+    $this->expectExceptionMessage('Invalid workflow structure: A trigger needs to be followed by an action.');
+    (new WorkflowWalker())->walk($workflow, [new TriggerNeedsToBeFollowedByActionRule()]);
+  }
+
+  public function testItFailsWhenFollowedByAStepNotBeingAnAction(): void {
+    $steps = [
+      'root' => $this->createStep('root', Step::TYPE_ROOT, ['t1']),
+      't1' => $this->createStep('t1', Step::TYPE_TRIGGER, ['a', 't2']),
+      'a' => $this->createStep('a', Step::TYPE_ACTION, []),
+      't2' => $this->createStep('t2', Step::TYPE_TRIGGER, ['a']),
+    ];
+    $workflow = $this->make(Workflow::class, ['getSteps' => $steps, 'getStep' => function($id) use ($steps) { return $steps[$id]??null; }]);
+
+
+    $this->expectException(UnexpectedValueException::class);
+    $this->expectExceptionMessage('Invalid workflow structure: A trigger needs to be followed by an action.');
+    (new WorkflowWalker())->walk($workflow, [new TriggerNeedsToBeFollowedByActionRule()]);
+  }
+}