Class IfStatement

src/ast/nodes/IfStatement.ts:24–209

const unset = Symbol('unset');

export default class IfStatement extends StatementBase implements DeoptimizableEntity {
	declare alternate: StatementNode | null;
	declare consequent: StatementNode;
	declare test: ExpressionNode;
	declare type: NodeType.tIfStatement;

	declare alternateScope?: TrackingScope;
	declare consequentScope: TrackingScope;
	private testValue: LiteralValueOrUnknown | typeof unset = unset;

	deoptimizeCache(): void {
		this.testValue = UnknownValue;
	}

	hasEffects(context: HasEffectsContext): boolean {
		if (this.test.hasEffects(context)) {
			return true;
		}
		const testValue = this.getTestValue();
		if (typeof testValue === 'symbol') {
			const { brokenFlow } = context;
			if (this.consequent.hasEffects(context)) return true;
			const consequentBrokenFlow = context.brokenFlow;
			context.brokenFlow = brokenFlow;
			if (this.alternate === null) return false;
			if (this.alternate.hasEffects(context)) return true;
			context.brokenFlow = context.brokenFlow && consequentBrokenFlow;
			return false;
		}
		return testValue ? this.consequent.hasEffects(context) : !!this.alternate?.hasEffects(context);
	}

	include(context: InclusionContext, includeChildrenRecursively: IncludeChildren): void {
		this.included = true;
		if (includeChildrenRecursively) {
			this.includeRecursively(includeChildrenRecursively, context);
		} else {
			const testValue = this.getTestValue();
			if (typeof testValue === 'symbol') {
				this.includeUnknownTest(context);
			} else {
				this.includeKnownTest(context, testValue);
			}
		}
	}

	parseNode(esTreeNode: GenericEsTreeNode): this {
		this.consequent = new (this.scope.context.getNodeConstructor(esTreeNode.consequent.type))(
			this,
			(this.consequentScope = new TrackingScope(this.scope))
		).parseNode(esTreeNode.consequent);
		if (esTreeNode.alternate) {
			this.alternate = new (this.scope.context.getNodeConstructor(esTreeNode.alternate.type))(
				this,
				(this.alternateScope = new TrackingScope(this.scope))
			).parseNode(esTreeNode.alternate);
		}
		return super.parseNode(esTreeNode);