Add support for overrideable configuration settings such as feature flags.

.github/workflows/gradle.yml

@@ -17,4 +17,6 @@ jobs:
         distribution: 'temurin'
         java-version: 17
     - name: Build with Gradle
+      env:
+        testCONFIGIsDefault: true
       run: ./gradlew build

src/main/java/org/carlmontrobotics/Config.java

@@ -0,0 +1,99 @@
+package org.carlmontrobotics;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.List;
+
+import edu.wpi.first.util.sendable.Sendable;
+import edu.wpi.first.util.sendable.SendableBuilder;
+
+abstract class Config implements Sendable {
+    public static final Config CONFIG = new Config() {
+        {
+            // Override config settings here, like this:
+            // this.exampleFlagEnabled = true;
+
+            // NOTE: PRs with overrides will NOT be merged because we don't want them
+            // polluting the master branch.
+            // Feel free to add them when testing, but remove them before pushing.
+        }
+    };
+
+    // Add additional config settings by declaring a protected field, and...
+    protected boolean exampleFlagEnabled = false;
+
+    // ...a public getter starting with "is" for booleans or "get" for other types.
+    // Do NOT remove this example. It is used by unit tests.
+    public boolean isExampleFlagEnabled() {
+        return exampleFlagEnabled;
+    }
+
+    // --- For clarity, place additional config settings ^above^ this line ---
+
+    private static class MethodResult {
+        String methodName = null;
+        Object retVal = null;
+        Object defaultRetVal = null;
+
+        MethodResult(String name, Object retVal, Object defaultRetval) {
+            this.methodName = name;
+            this.retVal = retVal;
+            this.defaultRetVal = defaultRetval;
+        }
+    }
+
+    private List<MethodResult> getMethodResults() {
+        var methodResults = new ArrayList<MethodResult>();
+        var defaultConfig = new Config() {
+        };
+        for (Method m : Config.class.getDeclaredMethods()) {
+            var name = m.getName();
+            if (!Modifier.isPublic(m.getModifiers()) || m.isSynthetic() || m.getParameterCount() != 0
+                    || !name.matches("^(get|is)[A-Z].*")) {
+                continue;
+            }
+            Object retVal = null;
+            try {
+                retVal = m.invoke(this);
+            } catch (Exception ex) {
+                retVal = ex;
+            }
+            Object defaultRetVal = null;
+            try {
+                defaultRetVal = m.invoke(defaultConfig);
+            } catch (Exception ex) {
+                defaultRetVal = ex;
+            }
+            methodResults.add(new MethodResult(name, retVal, defaultRetVal));
+        }
+        return methodResults;
+    }
+
+    @Override
+    public void initSendable(SendableBuilder builder) {
+        getMethodResults().forEach(mr -> {
+            if (!mr.retVal.equals(mr.defaultRetVal)) {
+                builder.publishConstString("%s()".formatted(mr.methodName),
+                        String.format("%s (default is %s)", mr.retVal, mr.defaultRetVal));
+            }
+        });
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder stringBuilder = new StringBuilder();
+        getMethodResults().forEach(mr -> {
+            if (!mr.retVal.equals(mr.defaultRetVal)) {
+                stringBuilder.append(
+                        String.format("%s() returns %s (default is %s)", mr.methodName, mr.retVal, mr.defaultRetVal));
+            }
+        });
+        if (stringBuilder.isEmpty()) {
+            stringBuilder.append("Using default config values");
+        } else {
+            stringBuilder.insert(0, "WARNING: USING OVERRIDDEN CONFIG VALUES\n");
+        }
+        return stringBuilder.toString();
+    }
+}

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

@@ -119,7 +119,10 @@ public class RobotContainer {
 
   public RobotContainer() {
     {
-      // SensorFactory.configureCamera();
+      // Put any configuration overrides to the dashboard and the terminal
+      SmartDashboard.putData("CONFIG overrides", Config.CONFIG);
+      System.out.println(Config.CONFIG);
+
       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/ConfigTest.java

@@ -0,0 +1,81 @@
+package org.carlmontrobotics;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+
+import edu.wpi.first.util.sendable.SendableBuilder;
+import edu.wpi.first.wpilibj.smartdashboard.SendableBuilderImpl;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.HashMap;
+
+public class ConfigTest {
+    @Test
+    void testIsExampleFlagEnabled() {
+        assertEquals(false, new Config() {
+        }.isExampleFlagEnabled());
+        assertEquals(true, new Config() {
+            {
+                this.exampleFlagEnabled = true;
+            }
+        }.isExampleFlagEnabled());
+    }
+
+    @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);
+            }
+        }) {
+            Config testConfig = new Config() {
+            };
+            testConfig.initSendable(testBuilder);
+            assertEquals(new HashMap<String, String>(), publishedStrings,
+                    "A default config should not publish anything.");
+
+            testConfig = new Config() {
+                {
+                    this.exampleFlagEnabled = true;
+                }
+            };
+            testConfig.initSendable(testBuilder);
+            assertEquals(new HashMap<String, String>() {
+                {
+                    this.put("isExampleFlagEnabled()", "true (default is false)");
+                }
+            }, publishedStrings, "A config with overrides should publish what is overriden.");
+        }
+    }
+
+    @Test
+    public void testToString() {
+        assertEquals("Using default config values", new Config() {
+        }.toString());
+        assertEquals("WARNING: USING OVERRIDDEN CONFIG VALUES\nisExampleFlagEnabled() returns true (default is false)",
+                new Config() {
+                    {
+                        exampleFlagEnabled = true;
+                    }
+                }.toString());
+    }
+
+    @Test
+    @EnabledIfEnvironmentVariable(named = "testCONFIGIsDefault", matches = "true", disabledReason = "not trying to modify GitHub master")
+    public void testNoConfigSettingsOverridden() 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);
+            }
+        }) {
+            Config.CONFIG.initSendable(testBuilder);
+            assertEquals(new HashMap<String, String>(), publishedStrings,
+                    "Config.CONFIG must be empty to be on the master branch.");
+        }
+    }
+}