feat(squareblock): implement initial positions

src/main/kotlin/blocks/implementation/SquareBlock.kt

@@ -0,0 +1,26 @@
+package blocks.implementation
+
+import blocks.Block
+import blocks.Rotation
+import movements.Direction
+import movements.Position
+
+class SquareBlock(private val initialPosition: Position) : Block {
+
+    private val positions = listOf(
+        Position(0, 0), Position(0, 1), Position(1, 0), Position(1, 1)
+    )
+
+    override fun getNeededPositions(): Collection<Position> {
+        return positions.map { position -> position.addAxes(initialPosition) }
+    }
+
+    override fun rotate(degree: Rotation) {
+        TODO("Not yet implemented")
+    }
+
+    override fun move(direction: Direction) {
+        TODO("Not yet implemented")
+    }
+
+}

src/test/kotlin/blocks/SquareBlock/SquareBlockTest.kt

@@ -0,0 +1,36 @@
+package blocks.SquareBlock
+
+import blocks.implementation.SquareBlock
+import movements.Position
+import org.junit.jupiter.api.Test
+import kotlin.test.assertEquals
+
+class SquareBlockTest {
+
+    @Test
+    fun `position 0,0 needed positions are (0,0), (0,1), (1,0), (1,1)`() {
+        val squareBlock = SquareBlock(Position(0,0))
+        assertEquals(
+            listOf(Position(0, 0), Position(0, 1), Position(1, 0), Position(1, 1)),
+            squareBlock.getNeededPositions()
+        )
+    }
+
+    @Test
+    fun `position 0,1 needed positions are (0,2), (0,3), (1,1), (1,2)`() {
+        val squareBlock = SquareBlock(Position(0,1))
+        assertEquals(
+            listOf(Position(0, 1), Position(0, 2), Position(1, 1), Position(1, 2)),
+            squareBlock.getNeededPositions()
+        )
+    }
+
+    @Test
+    fun `position 1,0 needed positions are (1,1), (1,2), (2,0), (2,1)`() {
+        val squareBlock = SquareBlock(Position(1,0))
+        assertEquals(
+            listOf(Position(1, 0), Position(1, 1), Position(2, 0), Position(2, 1)),
+            squareBlock.getNeededPositions()
+        )
+    }
+}