fix building

Author: JasperGeurtz

src/main/java/bwapi/Game.java

@@ -267,7 +267,7 @@ public void enableFlag(final Flag flag) {
 //
     //TODO
      public Set<Unit> getUnitsInRectangle(int left, int top, int right, int bottom, final UnitFilter filter) {
-        return null;
+        return new HashSet<>();
      }
 
     public Set<Unit> getUnitsInRectangle(final Position leftTop, final Position rightBottom, final UnitFilter filter) {
@@ -473,7 +473,7 @@ else if (!builder.getType().isFlyingBuilding() && type != Zerg_Nydus_Canal && !t
          // Ground getUnit dimension check
          if (type != Special_Start_Location) {
              final Position targPos = lt.toPosition().add(type.tileSize().toPosition().divide(2));
-             Set<Unit> unitsInRect = getUnitsInRectangle(lt.toPosition(), rb.toPosition(),
+             final Set<Unit> unitsInRect = getUnitsInRectangle(lt.toPosition(), rb.toPosition(),
                      (u -> !u.isFlying() && !u.isLoaded() && builder != null || type == Zerg_Nydus_Canal
                              && u.getLeft() <= targPos.x + type.dimensionRight()
                              && u.getTop() <= targPos.y + type.dimensionDown()

src/test/java/PlayTestListener.java

@@ -33,7 +33,7 @@ public void onFrame() {
                 .findFirst().get();
 
         // train workers
-        if (depot.isIdle()) {
+        if (depot.isIdle() && self.minerals() >= race.getWorker().mineralPrice()) {
             depot.train(race.getWorker());
         }
 
@@ -53,7 +53,7 @@ public void onFrame() {
 
         // make workers gather minerals if idle
         self.getUnits().stream()
-                .filter(u -> u.getType().isWorker() && u.isIdle())
+                .filter(u -> u.getType().isWorker() && u.isIdle() && u.isCompleted())
                 .forEach(u -> u.gather(minerals.poll()));