Function IsOutermostOptionalChain

internal/ast/utilities.go:375–380

Determines whether a node is the outermost `OptionalChain` in an ECMAScript `OptionalExpression`: 1. For `a?.b.c`, the outermost chain is `a?.b.c` (`c` is the end of the chain starting at `a?.`) 2. For `a?.b!`, the outermost chain is `a?.b` (`b` is the end of the chain starting at `a?.`) 3. For `(a

(node *Expression)

//  5. For `a?.(b?.c).d`, both `b?.c` and `a?.(b?.c)d` are outermost (`c` is the end of the chain starting at `b`, and `d` is
//     the end of the chain starting at `a?.`)
func IsOutermostOptionalChain(node *Expression) bool {
	parent := node.Parent
	return !IsOptionalChain(parent) || // cases 1, 2, and 3
		IsOptionalChainRoot(parent) || // case 4
		node != parent.Expression() // case 5
}

// Determines whether a node is the expression preceding an optional chain (i.e. `a` in `a?.b`).
func IsExpressionOfOptionalChainRoot(node *Node) bool {