Add unit test for GridItemDecoration

Signed-off-by: Stefan Niedermann <info@niedermann.it>

2 files changed, 106 insertions, 0 deletions

diff --git a/app/src/main/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecoration.java b/app/src/main/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecoration.java
index 2cfcee88..01743638 100644
--- a/app/src/main/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecoration.java
+++ b/app/src/main/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecoration.java
@@ -20,6 +20,9 @@ public class GridItemDecoration extends SectionItemDecoration {
 
     public GridItemDecoration(@NonNull ItemAdapter adapter, int spanCount, @Px int sectionLeft, @Px int sectionTop, @Px int sectionRight, @Px int sectionBottom, @Px int gutter) {
         super(adapter, sectionLeft, sectionTop, sectionRight, sectionBottom);
+        if(spanCount < 1) {
+            throw new IllegalArgumentException("Requires at least one span");
+        }
         this.spanCount = spanCount;
         this.adapter = adapter;
         this.gutter = gutter;
diff --git a/app/src/test/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecorationTest.java b/app/src/test/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecorationTest.java
new file mode 100644
index 00000000..8fb9ca45
--- /dev/null
+++ b/app/src/test/java/it/niedermann/owncloud/notes/main/items/grid/GridItemDecorationTest.java
@@ -0,0 +1,103 @@
+package it.niedermann.owncloud.notes.main.items.grid;
+
+import android.graphics.Rect;
+import android.os.Build;
+import android.view.View;
+
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.StaggeredGridLayoutManager;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import java.util.Arrays;
+
+import it.niedermann.owncloud.notes.main.items.ItemAdapter;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(sdk = {Build.VERSION_CODES.P})
+public class GridItemDecorationTest {
+
+    private final ItemAdapter itemAdapter = mock(ItemAdapter.class);
+    private final RecyclerView recyclerView = mock(RecyclerView.class);
+    private final View view = mock(View.class);
+    private final StaggeredGridLayoutManager.LayoutParams layoutParams = mock(StaggeredGridLayoutManager.LayoutParams.class);
+
+    @Test
+    public void getItemOffsets() {
+        when(view.getLayoutParams()).thenReturn(layoutParams);
+        when(itemAdapter.getFirstPositionOfViewType(anyInt())).thenReturn(0);
+        when(itemAdapter.getItemViewType(anyInt())).then((arg) -> Arrays.asList(0, 4, 9).contains(arg.getArgument(0, Integer.class))
+                ? ItemAdapter.TYPE_SECTION
+                : ItemAdapter.TYPE_NOTE_ONLY_TITLE);
+
+        assertThrows("Requires at least one column", IllegalArgumentException.class, () -> new GridItemDecoration(itemAdapter, 0, 5, 5, 5, 5, 5));
+
+        final GridItemDecoration oneColumn = new GridItemDecoration(itemAdapter, 1, 5, 5, 5, 5, 5);
+
+        testAssertion(oneColumn, 0, 0, true, 5, 5, 5, 5);
+        testAssertion(oneColumn, 0, 1, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 2, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 3, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 4, true, 5, 5, 5, 5);
+        testAssertion(oneColumn, 0, 5, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 6, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 7, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 8, false, 0, 5, 5, 5);
+        testAssertion(oneColumn, 0, 9, true, 5, 5, 5, 5);
+
+        final GridItemDecoration twoColumns = new GridItemDecoration(itemAdapter, 2, 5, 5, 5, 5, 5);
+
+        testAssertion(twoColumns, 0, 0, true, 5, 5, 5, 5);
+        testAssertion(twoColumns, 0, 1, false, 0, 5, 5, 5);
+        testAssertion(twoColumns, 1, 2, false, 0, 0, 5, 5);
+        testAssertion(twoColumns, 0, 3, false, 0, 5, 5, 5);
+        testAssertion(twoColumns, 0, 4, true, 5, 5, 5, 5);
+        testAssertion(twoColumns, 0, 5, false, 0, 5, 5, 5);
+        testAssertion(twoColumns, 1, 6, false, 0, 0, 5, 5);
+        testAssertion(twoColumns, 0, 7, false, 0, 5, 5, 5);
+        testAssertion(twoColumns, 0, 8, false, 0, 5, 5, 5);
+        testAssertion(twoColumns, 0, 9, true, 5, 5, 5, 5);
+
+        final GridItemDecoration threeColumns = new GridItemDecoration(itemAdapter, 3, 5, 5, 5, 5, 5);
+
+        testAssertion(threeColumns, 0, 0, true, 5, 5, 5, 5);
+        testAssertion(threeColumns, 0, 1, false, 0, 5, 5, 5);
+        testAssertion(threeColumns, 1, 2, false, 0, 0, 5, 5);
+        testAssertion(threeColumns, 2, 3, false, 0, 0, 5, 5);
+        testAssertion(threeColumns, 0, 4, true, 5, 5, 5, 5);
+        testAssertion(threeColumns, 0, 5, false, 0, 5, 5, 5);
+        testAssertion(threeColumns, 1, 6, false, 0, 0, 5, 5);
+        testAssertion(threeColumns, 2, 7, false, 0, 0, 5, 5);
+        testAssertion(threeColumns, 0, 8, false, 0, 5, 5, 5);
+        testAssertion(threeColumns, 0, 9, true, 5, 5, 5, 5);
+    }
+
+    @SuppressWarnings("SameParameterValue")
+    private void testAssertion(GridItemDecoration gid, int spanIndex, int position, boolean fullSpan, int top, int left, int right, int bottom) {
+        when(layoutParams.getSpanIndex()).thenReturn(spanIndex);
+        when(recyclerView.getChildAdapterPosition(any())).thenReturn(position);
+        final Rect result = new Rect();
+        gid.getItemOffsets(result, view, recyclerView, mock(RecyclerView.State.class));
+
+        if (fullSpan) {
+            verify(layoutParams).setFullSpan(true);
+        }
+        reset(layoutParams);
+        assertEquals(top, result.top);
+        assertEquals(left, result.left);
+        assertEquals(right, result.right);
+        assertEquals(bottom, result.bottom);
+    }
+}
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