Method isUndefinedMemberAccess

lib/DefinePlugin.js:786–813

(members, deps)

						 * @returns {boolean} true when the access resolves to `undefined`
						 */
						const isUndefinedMemberAccess = (members, deps) => {
							if (members.length <= chainPrefix.length) return false;
							for (let i = 0; i < chainPrefix.length; i++) {
								if (members[i] !== chainPrefix[i]) return false;
							}
							/** @type {CodeValue} */
							let value = /** @type {CodeValue} */ (obj);
							let path = key;
							for (let i = chainPrefix.length; i < members.length; i++) {
								// a leaf with members left is a real property access on a value
								if (!isObjectDefinition(value)) return false;
								const member = members[i];
								const nextPath = `${path}.${member}`;
								if (member in value) {
									value = value[member];
								} else if (
									Object.prototype.hasOwnProperty.call(definitions, nextPath)
								) {
									// defined via a dotted sibling key, e.g. `OBJECT.SUB2`
									deps.push(nextPath);
									value = definitions[nextPath];
								} else {
									return true;
								}
								path = nextPath;
							}
							return false;
						};
						parser.hooks.expressionMemberChain
							.for(chainRoot)
							.tap(PLUGIN_NAME, (expr, members) => {