Add WebApplicationTest.testPlaceholder w/ Selenium

Uses Selenium WebDriver and headless Chrome. Adds the "placeholder" class to the <p> element enclosing "Hello, World!" to enable the test assertion. If this passes in Github Actions, we're ready to start adding and testing actual web UI elements.
mbland · Nov 7, 2023 · e09d051 · e09d051
1 parent acb6d03
commit e09d051
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Showing 4 changed files with 71 additions and 1 deletion.
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
@@ -4,6 +4,7 @@ tomcatVer = "10.1.15"
 junitVer = "5.10.0"
 hamcrestVer = "2.2"
 antJunitVer = "1.10.14"
+seleniumVer = "4.15.0"
 
 [libraries.servlet]
 module = "jakarta.servlet:jakarta.servlet-api"
@@ -28,3 +29,7 @@ version.ref = "hamcrestVer"
 [libraries.antJunit]
 module = "org.apache.ant:ant-junit"
 version.ref = "antJunitVer"
+
+[libraries.selenium]
+module = "org.seleniumhq.selenium:selenium-java"
+version.ref = "seleniumVer"
diff --git a/strcalc/build.gradle.kts b/strcalc/build.gradle.kts
@@ -21,6 +21,7 @@ dependencies {
     testImplementation(libs.hamcrest)
     testImplementation(libs.tomcat)
     testImplementation(libs.jasper)
+    testImplementation(libs.selenium)
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
 

diff --git a/strcalc/src/main/webapp/index.html b/strcalc/src/main/webapp/index.html
@@ -5,6 +5,6 @@
     <title>String Calculator - Mike Bland Training</title>
 </head>
 <body>
-<p>Hello, World!</p>
+<p class="placeholder">Hello, World!</p>
 </body>
 </html>
diff --git a/...lc/src/test/java/com/mike_bland/training/testing/stringcalculator/WebApplicationTest.java b/...lc/src/test/java/com/mike_bland/training/testing/stringcalculator/WebApplicationTest.java
@@ -7,8 +7,66 @@
 package com.mike_bland.training.testing.stringcalculator;
 
 import com.mike_bland.training.testing.annotations.LargeTest;
+import com.mike_bland.training.testing.utils.LocalServer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.chrome.ChromeDriver;
+import org.openqa.selenium.chrome.ChromeOptions;
+
+import java.io.IOException;
+import java.net.URI;
+import java.time.Duration;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class WebApplicationTest {
+    private static LocalServer app;
+    private static URI appUri;
+    private WebDriver driver;
+
+    @BeforeAll
+    static void setUpClass() throws IOException, InterruptedException {
+        app = new LocalServer(
+                "dockerfiles/Dockerfile.tomcat-test", 8080
+        );
+        appUri = app.start(2500);
+    }
+
+    @BeforeEach
+    void setUp() {
+        // - https://www.selenium.dev/documentation/webdriver/browsers/chrome/
+        // - https://github.com/GoogleChrome/chrome-launcher/blob/main/docs/chrome-flags-for-tools.md
+        // - https://peter.sh/experiments/chromium-command-line-switches/
+        var options = new ChromeOptions();
+        options.addArguments("--headless");
+        driver = new ChromeDriver(options);
+    }
+
+    @AfterEach
+    void tearDown() {
+        driver.quit();
+    }
+
+    @AfterAll
+    static void tearDownClass() throws IOException, InterruptedException {
+        app.stop(2500);
+    }
+
+    String endpoint(String relPath) {
+        if (!relPath.startsWith("/")) {
+            final var msg = "endpoint path should begin with '/', got: \"%s\"";
+            throw new IllegalArgumentException(msg.formatted(relPath));
+        }
+        return appUri
+                .resolve("%s%s".formatted(Servlet.DEFAULT_ROOT, relPath))
+                .toString();
+    }
+
     // This placeholder test exists solely to allow the Gradle "test" task to
     // pass until actual @SmallTests are present:
     //
@@ -17,5 +75,11 @@ public class WebApplicationTest {
     //  Please replace or delete it when you're ready to add actual tests.
     @LargeTest
     void testPlaceholder() {
+        driver.get(endpoint("/"));
+        driver.manage().timeouts().implicitlyWait(Duration.ofMillis(500));
+
+        WebElement body = driver.findElement(By.cssSelector("p.placeholder"));
+
+        assertEquals("Hello, World!", body.getText());
     }
 }