Reorganized power tests ...

... and changed creation of fake tiles so update() implementations have all required dependencies

tests/src/test/java/power/PowerTestFixture.java

@@ -0,0 +1,84 @@
+package power;
+
+import io.anuke.mindustry.Vars;
+import io.anuke.mindustry.content.blocks.Blocks;
+import io.anuke.mindustry.core.ContentLoader;
+import io.anuke.mindustry.world.Block;
+import io.anuke.mindustry.world.Tile;
+import io.anuke.mindustry.world.blocks.PowerBlock;
+import io.anuke.mindustry.world.blocks.power.Battery;
+import io.anuke.mindustry.world.blocks.power.PowerGenerator;
+import io.anuke.mindustry.world.modules.PowerModule;
+import org.junit.jupiter.api.BeforeAll;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+/** This class provides objects commonly used by power related unit tests.
+ *  For now, this is a helper with static methods, but this might change.
+ * */
+public class PowerTestFixture{
+
+    @BeforeAll
+    static void initializeDependencies(){
+        Vars.content = new ContentLoader();
+        Vars.content.load();
+        Vars.threads = new FakeThreadHandler();
+    }
+
+    protected static PowerGenerator createFakeProducerBlock(float producedPower){
+        return new PowerGenerator("fakegen"){{
+            powerProduction = producedPower;
+        }};
+    }
+
+    protected static Battery createFakeBattery(float capacity, float ticksToFill){
+        return new Battery("fakebattery"){{
+            consumes.powerBuffered(capacity, ticksToFill);
+        }};
+    }
+
+    protected static Block createFakeDirectConsumer(float powerPerTick, float minimumSatisfaction){
+        return new PowerBlock("fakedirectconsumer"){{
+            consumes.powerDirect(powerPerTick, minimumSatisfaction);
+        }};
+    }
+
+    protected static Block createFakeBufferedConsumer(float capacity, float ticksToFill){
+        return new PowerBlock("fakebufferedconsumer"){{
+            consumes.powerBuffered(capacity, ticksToFill);
+        }};
+    }
+    /**
+     * Creates a fake tile on the given location using the given block.
+     * @param x     The X coordinate.
+     * @param y     The y coordinate.
+     * @param block The block on the tile.
+     * @return The created tile or null in case of exceptions.
+     */
+    protected static Tile createFakeTile(int x, int y, Block block){
+        try{
+            Tile tile = new Tile(x, y);
+
+            // Using the Tile(int, int, byte, byte) constructor would require us to register any fake block or tile we create
+            // Since this part shall not be part of the test and would require more work anyway, we manually set the block and floor
+            // and call the private changed() method through reflections.
+
+            Field field = Tile.class.getDeclaredField("wall");
+            field.setAccessible(true);
+            field.set(tile, block);
+
+            field = Tile.class.getDeclaredField("floor");
+            field.setAccessible(true);
+            field.set(tile, Blocks.sand);
+
+            Method method = Tile.class.getDeclaredMethod("changed");
+            method.setAccessible(true);
+            method.invoke(tile);
+
+            return tile;
+        }catch(Exception ex){
+            return null;
+        }
+    }
+}