Merge pull request #4 from lensesio/feat/NGN-1216_DocumentUdfInstalla…

…tion

NGN-1216: Added test example for udafs

src/test/java/io/lenses/sql/udaf/count_doubleTest.java

@@ -0,0 +1,46 @@
+package io.lenses.sql.udaf;
+
+import io.lenses.sql.udf.UdfException;
+import io.lenses.sql.udf.datatype.DataType;
+import io.lenses.sql.udf.value.LongValue;
+import io.lenses.sql.udf.value.Value;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class count_doubleTest {
+    private count_double func = new count_double();
+
+    @Test
+    public void typesTheUdaf() throws UdfException {
+        assertTrue(func.typer(DataType.ltDouble()).isLong());
+        assertTrue(func.typer(DataType.ltFloat()).isLong());
+        assertTrue(func.typer(DataType.ltInt()).isLong());
+        assertTrue(func.typer(DataType.ltLong()).isLong());
+
+        assertTrue(func.typer(DataType.ltOptional(DataType.ltDouble())).isLong());
+        assertTrue(func.typer(DataType.ltOptional(DataType.ltFloat())).isLong());
+        assertTrue(func.typer(DataType.ltOptional(DataType.ltInt())).isLong());
+        assertTrue(func.typer(DataType.ltOptional(DataType.ltLong())).isLong());
+    }
+
+    @Test
+    public void correctlyCalculatesEmpty() throws UdfException {
+        assertEquals(func.empty().get(), 0L);
+    }
+
+    @Test
+    public void correctlyAddsElements() throws UdfException {
+        Value added1  = func.add(func.empty(), func.empty(), null);
+        assertEquals(added1.get(), 2L);
+    }
+
+    @Test
+    public void correctlyMergesElements() throws UdfException {
+        Value merge  = func.merge(null, new LongValue(3), new LongValue(2));
+        assertEquals(merge.get(), 5L);
+    }
+
+
+}