Add build info to SmartDashboard.

Includes build date, current branch, and most recent commit hash.

.gitignore

@@ -224,3 +224,4 @@ simgui-ds.json
 simgui.json
 *.wpilog
 *.dat
+src/main/deploy/BuildInfo.properties

build.gradle

@@ -1,6 +1,7 @@
 plugins {
     id "java"
     id "edu.wpi.first.GradleRIO" version "2024.3.2"
+    id "com.peterabeles.gversion" version "1.10"    
 }
 
 java {
@@ -110,3 +111,13 @@ wpi.java.configureTestTasks(test)
 tasks.withType(JavaCompile) {
     options.compilerArgs.add '-XDstringConcat=inline'
 }
+
+project.compileJava.dependsOn(createVersionFile)
+gversion {
+    language = "Properties"
+    srcDir       = "src/main/deploy/"
+    className    = "BuildInfo.properties"
+    dateFormat   = "yyyy-MM-dd HH:mm:ss z"
+    timeZone     = "America/Los_Angeles"
+    indent       = "  "
+}

src/main/java/org/carlmontrobotics/BuildInfo.java

@@ -0,0 +1,45 @@
+package org.carlmontrobotics;
+
+import java.util.Properties;
+import java.io.File;
+import java.io.InputStream;
+import java.nio.file.Path;
+import java.nio.file.Files;
+
+import edu.wpi.first.util.sendable.Sendable;
+import edu.wpi.first.util.sendable.SendableBuilder;
+import edu.wpi.first.wpilibj.Filesystem;
+
+public class BuildInfo implements Sendable {
+    private Properties props = new Properties();
+
+    static private BuildInfo instance = null;
+
+    public static BuildInfo getInstance() {
+        if (instance == null) {
+            instance = new BuildInfo();
+        }
+        return instance;
+    }
+
+    private BuildInfo() {
+        Path path = Path
+                .of(Filesystem.getDeployDirectory().getAbsolutePath() + File.separator + "BuildInfo.properties");
+        try (InputStream is = Files.newInputStream(path)) {
+            props.load(is);
+        } catch (Exception ex) {
+            System.err.println("Error reading build properties from %s".formatted(path));
+        }
+    }
+
+    @Override
+    public void initSendable(SendableBuilder builder) {
+        props.stringPropertyNames().forEach(name -> {
+            var value = props.getProperty(name);
+            // Workaround bug (https://github.com/lessthanoptimal/gversion-plugin/pull/14)
+            // where the gversion plugin surrounds values with quotes.
+            value = value.replaceAll("\"", "");
+            builder.publishConstString(name, value);
+        });
+    }
+}

src/main/java/org/carlmontrobotics/RobotContainer.java

@@ -123,6 +123,8 @@ public RobotContainer() {
       SmartDashboard.putData("CONFIG overrides", Config.CONFIG);
       System.out.println(Config.CONFIG);
 
+      SmartDashboard.putData("BuildConstants", BuildInfo.getInstance());
+
       SmartDashboard.setDefaultBoolean("babymode", babyMode);
       SmartDashboard.setPersistent("babymode");
       //safe auto setup... stuff in setupAutos() is not safe to run here - will break robot

src/test/java/org/carlmontrobotics/BuildInfoTest.java

@@ -0,0 +1,37 @@
+package org.carlmontrobotics;
+
+import java.util.HashMap;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import edu.wpi.first.util.sendable.SendableBuilder;
+import edu.wpi.first.wpilibj.smartdashboard.SendableBuilderImpl;
+
+public class BuildInfoTest {
+    @Test
+    void testGetInstance() {
+        assertNotNull(BuildInfo.getInstance());
+    }
+
+    @Test
+    void testInitSendable() throws Exception {
+        var publishedStrings = new HashMap<String, String>();
+        try (SendableBuilder testBuilder = new SendableBuilderImpl() {
+            @Override
+            public void publishConstString(String key, String value) {
+                publishedStrings.put(key, value);
+            }
+        }) {
+            BuildInfo.getInstance().initSendable(testBuilder);
+            String actualBuildDate = publishedStrings.get("build_date");
+            assertNotNull(actualBuildDate);
+            assertTrue(actualBuildDate.matches("[^\"']+"),
+                    "build_date (%s) must not contain quotes".formatted(actualBuildDate));
+            String actualSha = publishedStrings.get("sha");
+            assertNotNull(actualSha);
+            assertTrue(actualSha.matches("(UNKNOWN|[a-f0-9]+)"), "sha (%s) is not valid".formatted(actualSha));
+        }
+    }
+}