Action

Action is a sealed interface representing an immutable, reusable execution unit processed by a Runner.

public sealed interface Action
        permits Assert, Conditional, Delay, Instance, Isolated, Parallel, Repeat, Scope, Sequence, Static, Step, Timeout, Until {

    String displayName();
}

Design

An Action defines structure and identity, not execution logic. The runner and scheduler own all descriptor traversal, status transitions, and listener callbacks. Actions carry only their display name; execution behavior is handled by the scheduler interpreting each sealed subtype.

All action subtypes are immutable after construction. For configurable actions, use the corresponding Builder subtype to produce an immutable action snapshot via Builder.build().

Subtypes

Type	Description
Step	Terminal action wrapping a ContextConsumer.
Assert	Terminal action evaluating a boolean condition.
Sequence	Composite: executes children sequentially. Dependent/independent modes.
Parallel	Composite: executes children concurrently with bounded admission.
Scope	Composite: before-body-after with lifecycle guarantee (after always runs).
Static	Composite: before-body-after without a fixture instance.
Instance	Composite: creates a fixture instance, runs body, destroys instance.
Isolated	Composite: executes body under a named re-entrant lock. Compose with Instance for state isolation.
Delay	Terminal: pauses for a duration.
Repeat	Decorator: executes a child action N times.
Timeout	Decorator: executes a child action with a wall-clock deadline.
Conditional	Composite: evaluates a Predicate<Context>; runs body when true, skips entire subtree when false.
Until	Decorator: executes child repeatedly until predicate satisfied, body passes, or iterations exhausted.

Composition

Build action trees by nesting actions through builders:

import org.paramixel.api.action.Action;
import org.paramixel.api.action.Scope;
import org.paramixel.api.action.Sequence;
import org.paramixel.api.action.Step;

Action test = Scope.builder("browser test")
        .before(Step.of("start browser", ctx -> startBrowser()))
        .body(Sequence.builder("scenario")
                .child(Step.of("open page", ctx -> openPage()))
                .child(Step.of("verify", ctx -> verifyPage()))
                .build())
        .after(Step.of("stop browser", ctx -> stopBrowser()))
        .build();

See Builder for the Builder sealed interface and its subtypes.