Ongoing discussion about issue when shading Project Reactor

ContextualScenarious.java

package com.example.demo;

import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.test.StepVerifier;

import java.util.NoSuchElementException;

import org.junit.Test;
import org.reactivestreams.Publisher;

/**
 * This meant to be read top to bottm. The first test is the scenario describe in the official reactor docs,
 * the second test describes a possible messy situation for the user, when the wrong Flux get's imported somehow
 * and the third one shows the usage of our API.
 * </p>
 * As we only expose reactive streams, we cannot expose our contextual information and cannot / do not expect
 * contextual information coming in.
 * </p>
 * Spring Data Neo4j wraps the reactive streams returned from the driver inside Flux' and Monos (Flux.from(Publisher)).
 * Contextual information stays on that level.
 */
public class ContextualScenarious {

	@Test
	public void normalContextualFlow() {

		// Reading about the contextual api:
		// https://projectreactor.io/docs/core/release/reference/#_the_context_api

		// One of the main takeaways is
		//
		// > Note that in your chain of operators, the relative positions of where you write to the Context and where you
		// > read from it matters: the Context is immutable and its content can only be seen by operators above it, as
		// > demonstrated in the following code example:

		// "Above" is meant pretty literally above: The usage of context elements happens in above the line were the context element is added

		Publisher<String> publisher = Mono.just("Data")
			.flatMap(s -> Mono.subscriberContext().map(ctx -> s + ctx.get("k")));

		Mono<String> r = Mono.from(publisher)
			.subscriberContext(ctx -> ctx.put("k", "'"));

		StepVerifier.create(r)
			.expectNext("Data'")
			.verifyComplete();
	}

	@Test
	public void shadedTypesAndStandardTypesGetsMixedUp() {
		// This is unlikely, but you never now
		Publisher<String> publisher = org.neo4j.driver.internal.shaded.reactor.core.publisher.Mono.just("Data")
			.flatMap(s -> org.neo4j.driver.internal.shaded.reactor.core.publisher.Mono.subscriberContext()
				.map(ctx -> s + ctx.get("k")));

		Mono<String> r = Mono.from(publisher)
			.subscriberContext(ctx -> ctx.put("k", "'"));

		StepVerifier.create(r)
			.expectErrorMatches(NoSuchElementException.class::isInstance)
			.verify();
	}

	static class FakeRxStatementResult {
		Publisher<String> records() {
			return org.neo4j.driver.internal.shaded.reactor.core.publisher.Flux.just("A", "B", "C");
		}
	}

	static class FakeRxSession {
		FakeRxStatementResult run(String statementTemplate) {
			return new FakeRxStatementResult();
		}

		<T> Publisher<T> close() {
			return org.neo4j.driver.internal.shaded.reactor.core.publisher.Mono.empty();
		}
	}

	@Test
	public void normalUsageOfOurDriverApi() {

		// Assumes a user don't want to work with raw publishers ;)
		Flux<String> strings = Flux.usingWhen(
			Mono.fromSupplier(FakeRxSession::new),
			// The user always has to wrap in a standard flux, he has no means of adding or using the
			// Project reactor context here.
			// The driver itself doesn't make use of the context and even if it would, it could not gave
			// away the information to the outside world, as our api shall be publishers alonw.
			s -> Flux.from(
				s.run("MATCH (m:Movie) RETURN m ORDER BY m.name ASC").records()
			),
			FakeRxSession::close
		);

		strings = strings
			// The user is free to do whatever he wants with the so created flux, i.e. adding contextual information
			.flatMap(s -> Mono.subscriberContext().map(ctx -> s + ctx.get("k")))
			.subscriberContext(ctx -> ctx.put("k", "'"));

		StepVerifier.create(strings)
			.expectNext("A'", "B'", "C'")
			.verifyComplete();
	}

}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- I used Spring Boot's dependency cause I'm lazy… -->
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.6.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>demo</name>
	<description>Demo project for Spring Boot</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-webflux</artifactId>
		</dependency>
		<dependency>
			<groupId>org.neo4j.driver</groupId>
			<artifactId>neo4j-java-driver</artifactId>
			<version>2.0.0-alpha03</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>io.projectreactor</groupId>
			<artifactId>reactor-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>
</project>