spring-ai/langchain4j-interop/src/test/java/com/ankurm/interop/BothStartersTest.java

package com.ankurm.interop;

import static org.assertj.core.api.Assertions.assertThat;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.junit.jupiter.api.Test;
import org.springframework.boot.WebApplicationType;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Configuration;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.context.ConfigurableApplicationContext;

class BothStartersTest {

    @Configuration
    @EnableAutoConfiguration
    static class BothApp { }

    record Outcome(String result, List<String> beans) { }

    static Outcome start(FakeOpenAi fake, String... extra) {
        List<String> props = new ArrayList<>(List.of(
                "spring.ai.openai.base-url=" + fake.url(), "spring.ai.openai.api-key=k",
                "spring.ai.openai.chat.options.model=gpt-6.1-sol",
                "spring.ai.mcp.client.enabled=false", "spring.ai.mcp.server.enabled=false",
                "langchain4j.open-ai.chat-model.base-url=" + fake.url() + "/v1",
                "langchain4j.open-ai.chat-model.api-key=k",
                "langchain4j.open-ai.chat-model.model-name=gpt-6.1-sol"));
        props.addAll(List.of(extra));
        try (ConfigurableApplicationContext ctx = new SpringApplicationBuilder(BothApp.class)
                .web(WebApplicationType.NONE).properties(props.toArray(String[]::new)).run()) {
            List<String> beans = new ArrayList<>();
            for (String n : ctx.getBeanDefinitionNames()) {
                Class<?> c = null;
                try {
                    c = ctx.getType(n);
                } catch (Exception ignored) {
                    // not resolvable without creating it
                }
                if (c != null && (c.getName().endsWith("OpenAiChatModel") || c.getName().endsWith("ChatClient$Builder")))
                    beans.add(n + " -> " + c.getName());
            }
            beans.add("(count) beans of type dev.langchain4j.model.chat.ChatModel: " + ctx.getBeanNamesForType(dev.langchain4j.model.chat.ChatModel.class).length);
            beans.add("(count) beans of type org.springframework.ai.chat.model.ChatModel: " + ctx.getBeanNamesForType(org.springframework.ai.chat.model.ChatModel.class).length);
            return new Outcome("context started", beans);
        } catch (Exception e) {
            Throwable root = e;
            while (root.getCause() != null) root = root.getCause();
            String msg = root.getMessage();
            if (root.getClass().getSimpleName().equals("BeanDefinitionOverrideException")) {
                Matcher m = Pattern.compile("factoryBeanName=([\\w.$]+)").matcher(msg);
                List<String> owners = new ArrayList<>();
                while (m.find()) owners.add(m.group(1));
                msg = "bean 'openAiChatModel' is defined twice, by " + String.join(" and by ", owners);
            }
            return new Outcome("FAILED: " + root.getClass().getSimpleName() + ": " + msg, List.of());
        }
    }

    @Test
    void bothStartersInOneApplication() throws Exception {
        try (FakeOpenAi fake = new FakeOpenAi()) {
            Outcome both = start(fake);
            Outcome excluded = start(fake, "spring.autoconfigure.exclude=dev.langchain4j.openai.spring.OpenAiAutoConfiguration");
            Outcome overriding = start(fake, "spring.main.allow-bean-definition-overriding=true");
            try (var t = new Transcript("01-both-starters.txt", "Both starters in one Spring Boot 4.1.1 application")) {
                t.line("Spring AI: spring-ai-starter-model-openai 2.0.1.  LangChain4j: langchain4j-open-ai-spring-boot4-starter 1.22.0-beta32.");
                t.blank();
                t.line("1. Both starters, nothing else:");
                t.line("   %s", both.result());
                t.blank();
                t.line("2. spring.autoconfigure.exclude=dev.langchain4j.openai.spring.OpenAiAutoConfiguration:");
                t.line("   %s", excluded.result());
                excluded.beans().forEach(b -> t.line("   %s", b.startsWith("(count)") ? b.substring(8) : "bean " + b));
                t.blank();
                t.line("3. spring.main.allow-bean-definition-overriding=true:");
                t.line("   %s", overriding.result());
                overriding.beans().forEach(b -> t.line("   %s", b.startsWith("(count)") ? b.substring(8) : "bean " + b));
            }
            assertThat(both.result()).startsWith("FAILED: BeanDefinitionOverrideException");
            assertThat(excluded.result()).isEqualTo("context started");
            assertThat(overriding.result()).isEqualTo("context started");
        }
    }
}