Fix Hot Reload (#1045)

pom.xml

@@ -77,13 +77,6 @@
             <artifactId>spring-boot-starter-actuator</artifactId>
         </dependency>
 
-        <!-- hot swapping, disable cache for template, enable live reload -->
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-devtools</artifactId>
-            <optional>true</optional>
-        </dependency>
-
         <!-- More Spring pieces. -->
         <dependency>
             <groupId>org.springframework.security</groupId>

src/main/java/edu/hawaii/its/groupings/configuration/LocalDevHotReloadConfig.java

@@ -0,0 +1,32 @@
+package edu.hawaii.its.groupings.configuration;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Objects;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.core.io.ClassPathResource;
+import org.thymeleaf.TemplateEngine;
+import org.thymeleaf.templateresolver.FileTemplateResolver;
+
+@Configuration
+@Profile({"localhost", "dockerhost"})
+public class LocalDevHotReloadConfig {
+    public LocalDevHotReloadConfig(final TemplateEngine templateEngine) throws IOException {
+        final ClassPathResource applicationProp = new ClassPathResource("application.properties");
+        if (applicationProp.isFile()) {
+            File sourceRoot = applicationProp.getFile().getParentFile();
+            while (Objects.requireNonNull(sourceRoot.listFiles((dir, name) -> name.equals("mvnw"))).length != 1) {
+                sourceRoot = sourceRoot.getParentFile();
+            }
+            final FileTemplateResolver fileTemplateResolver = new FileTemplateResolver();
+            fileTemplateResolver.setPrefix(sourceRoot.getPath() + "/src/main/resources/templates/");
+            fileTemplateResolver.setSuffix(".html");
+            fileTemplateResolver.setCacheable(false);
+            fileTemplateResolver.setCharacterEncoding("UTF-8");
+            fileTemplateResolver.setCheckExistence(true);
+            templateEngine.setTemplateResolver(fileTemplateResolver);
+        }
+    }
+}

src/test/java/edu/hawaii/its/groupings/configuration/LocalDevHotReloadConfigTest.java

@@ -0,0 +1,50 @@
+package edu.hawaii.its.groupings.configuration;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.context.ActiveProfiles;
+import org.thymeleaf.TemplateEngine;
+import org.thymeleaf.templateresolver.FileTemplateResolver;
+import org.thymeleaf.templateresolver.ITemplateResolver;
+
+import java.io.IOException;
+
+@ActiveProfiles({ "localhost", "dockerhost" })
+public class LocalDevHotReloadConfigTest {
+
+    @MockBean
+    LocalDevHotReloadConfig localDevHotReloadConfig;
+
+    @Test
+    public void testConstructorWithValidTemplateEngine() throws IOException {
+        TemplateEngine templateEngine = spy(new TemplateEngine());
+        localDevHotReloadConfig = new LocalDevHotReloadConfig(templateEngine);
+        verify(templateEngine, times(1)).setTemplateResolver(any(ITemplateResolver.class));
+    }
+
+    @Test
+    public void testConstructorWithNullTemplateEngine() {
+        assertThrows(NullPointerException.class, () -> new LocalDevHotReloadConfig(null));
+    }
+
+    @Test
+    public void testConstructorConfiguresCorrectTemplateResolverProperties() throws IOException {
+        TemplateEngine templateEngine = new TemplateEngine();
+        localDevHotReloadConfig = new LocalDevHotReloadConfig(templateEngine);
+        ITemplateResolver resolver = templateEngine.getTemplateResolvers().iterator().next();
+        assertTrue(resolver instanceof FileTemplateResolver);
+        FileTemplateResolver fileResolver = (FileTemplateResolver) resolver;
+        assertFalse(fileResolver.isCacheable());
+        assertEquals("UTF-8", fileResolver.getCharacterEncoding());
+        assertTrue(fileResolver.getCheckExistence());
+    }
+}