Report plugin activation in /info at request time, not at startup

src/main/java/org/ohdsi/webapi/info/InfoService.java

@@ -34,17 +34,15 @@
 @RequestMapping("/info")
 public class InfoService {
 
-    private final Info info;
+    private final String version;
+    private final BuildInfo buildInfo;
+    private final List<ConfigurationInfo> configurationInfoList;
 
     public InfoService(BuildProperties buildProperties, BuildInfo buildInfo, List<ConfigurationInfo> configurationInfoList) {
 
-        String version = getVersion(buildProperties);
-
-        this.info = new Info(
-                version,
-                buildInfo,
-                configurationInfoList.stream().collect(Collectors.toMap(ConfigurationInfo::getKey, ConfigurationInfo::getProperties))
-        );
+        this.version = getVersion(buildProperties);
+        this.buildInfo = buildInfo;
+        this.configurationInfoList = configurationInfoList;
     }
 
     /**
@@ -53,7 +51,11 @@ public InfoService(BuildProperties buildProperties, BuildInfo buildInfo, List<Co
     @GetMapping(produces = MediaType.APPLICATION_JSON_VALUE)
     public Info getInfo() {
 
-        return info;
+        return new Info(
+                version,
+                buildInfo,
+                configurationInfoList.stream().collect(Collectors.toMap(ConfigurationInfo::getKey, ConfigurationInfo::getProperties))
+        );
     }
 
     private String getVersion(BuildProperties buildProperties) {

src/main/java/org/ohdsi/webapi/plugins/PluginsConfigurationInfo.java

@@ -7,22 +7,35 @@
 import org.springframework.beans.factory.annotation.Autowired;
 
 import java.util.Collections;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 
 @Component
 public class PluginsConfigurationInfo extends ConfigurationInfo {
     private static final String KEY = "plugins";
 
+    private final List<WebApiPlugin> plugins;
+    private final Boolean atlasgisEnabled;
+
     public PluginsConfigurationInfo(
             @Autowired(required = false) List<WebApiPlugin> plugins,
             @Value("${atlasgis.enabled}") Boolean atlasgisEnabled) {
-        if (plugins == null) {
-            plugins = Collections.emptyList();
-        }
+        this.plugins = plugins == null ? Collections.emptyList() : plugins;
+        this.atlasgisEnabled = atlasgisEnabled;
+    }
+
+    // A plugin can only report itself active once its engine has started, which
+    // may happen after this bean is built, and it can stop again at runtime.
+    // Ask on every read rather than freezing whatever was true at construction.
+    @Override
+    public Map<String, Object> getProperties() {
+        Map<String, Object> current = new LinkedHashMap<>();
         for (WebApiPlugin plugin : plugins) {
-            properties.put(plugin.getId() + "Enabled", plugin.isActive());
+            current.put(plugin.getId() + "Enabled", plugin.isActive());
         }
-        properties.put("atlasgisEnabled", atlasgisEnabled);
+        current.put("atlasgisEnabled", atlasgisEnabled);
+        return current;
     }
 
     @Override

src/test/java/org/ohdsi/webapi/info/InfoServiceTest.java

@@ -0,0 +1,38 @@
+package org.ohdsi.webapi.info;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.Collections;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.Test;
+import org.ohdsi.webapi.plugins.PluginsConfigurationInfo;
+import org.ohdsi.webapi.plugins.WebApiPlugin;
+import org.springframework.boot.info.BuildProperties;
+
+public class InfoServiceTest {
+
+    @Test
+    public void infoReflectsPluginStateAtRequestTime() {
+
+        AtomicBoolean active = new AtomicBoolean(false);
+        WebApiPlugin plugin = mock(WebApiPlugin.class);
+        when(plugin.getId()).thenReturn("trexsql");
+        when(plugin.isActive()).thenAnswer(invocation -> active.get());
+
+        BuildProperties buildProperties = mock(BuildProperties.class);
+        when(buildProperties.getVersion()).thenReturn("3.0.0-SNAPSHOT");
+
+        InfoService service = new InfoService(
+                buildProperties,
+                mock(BuildInfo.class),
+                Collections.singletonList(new PluginsConfigurationInfo(Collections.singletonList(plugin), false)));
+
+        assertEquals("3.0.0", service.getInfo().getVersion());
+        assertEquals(false, service.getInfo().getConfiguration().get("plugins").get("trexsqlEnabled"));
+
+        active.set(true);
+        assertEquals(true, service.getInfo().getConfiguration().get("plugins").get("trexsqlEnabled"));
+    }
+}

src/test/java/org/ohdsi/webapi/plugins/PluginsConfigurationInfoTest.java

@@ -0,0 +1,47 @@
+package org.ohdsi.webapi.plugins;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Collections;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.Test;
+
+public class PluginsConfigurationInfoTest {
+
+    private static WebApiPlugin plugin(String id, AtomicBoolean active) {
+
+        return new WebApiPlugin() {
+            public String getId() { return id; }
+            public String getName() { return id; }
+            public String getVersion() { return "1.0"; }
+            public boolean isActive() { return active.get(); }
+        };
+    }
+
+    @Test
+    public void reportsPluginActivationAtReadTimeNotConstructionTime() {
+
+        AtomicBoolean active = new AtomicBoolean(false);
+        PluginsConfigurationInfo info =
+                new PluginsConfigurationInfo(Collections.singletonList(plugin("trexsql", active)), false);
+
+        assertEquals(false, info.getProperties().get("trexsqlEnabled"));
+
+        active.set(true);
+        assertEquals(true, info.getProperties().get("trexsqlEnabled"));
+
+        active.set(false);
+        assertEquals(false, info.getProperties().get("trexsqlEnabled"));
+    }
+
+    @Test
+    public void omitsPluginKeysWhenNoPluginsAreRegistered() {
+
+        PluginsConfigurationInfo info = new PluginsConfigurationInfo(null, true);
+
+        assertEquals(1, info.getProperties().size());
+        assertEquals(true, info.getProperties().get("atlasgisEnabled"));
+        assertTrue(!info.getProperties().containsKey("trexsqlEnabled"));
+    }
+}