Introduce the AbstractArrayCodecUnitTests class

The AbstractArrayCodecUnitTests class helps testing array codecs by
providing generic tests.

[pgjdbc#394][pgjdbc#403]

Author: Francisco Guerrero

src/test/java/io/r2dbc/postgresql/codec/AbstractArrayCodecUnitTests.java

@@ -0,0 +1,169 @@
+package io.r2dbc.postgresql.codec;
+
+import io.netty.buffer.ByteBuf;
+import io.r2dbc.postgresql.client.EncodedParameter;
+import io.r2dbc.postgresql.client.ParameterAssert;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static io.r2dbc.postgresql.client.EncodedParameter.NULL_VALUE;
+import static io.r2dbc.postgresql.message.Format.FORMAT_BINARY;
+import static io.r2dbc.postgresql.message.Format.FORMAT_TEXT;
+import static io.r2dbc.postgresql.util.ByteBufUtils.encode;
+import static io.r2dbc.postgresql.util.TestByteBufAllocator.TEST;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+
+/**
+ * Abstract class for unit testing {@link ArrayCodec}s. It provides
+ * generic tests for array codecs.
+ */
+abstract class AbstractArrayCodecUnitTests<T> {
+
+    ArrayCodec<T> codec;
+
+    abstract ArrayCodec<T> createInstance();
+
+    @BeforeEach
+    void setUp() {
+        codec = createInstance();
+    }
+
+    abstract PostgresqlObjectId getPostgresqlObjectId();
+
+    abstract PostgresqlObjectId getArrayPostgresqlObjectId();
+
+    abstract ByteBuf getSingleDimensionBinaryArray();
+
+    abstract ByteBuf getTwoDimensionBinaryArray();
+
+    abstract Class<? extends T[]> getSingleDimensionArrayType();
+
+    abstract Class<? extends T[][]> getTwoDimensionArrayType();
+
+    abstract T[] getExpectedSingleDimensionArray();
+
+    abstract T[][] getExpectedTwoDimensionArray();
+
+    abstract String getSingleDimensionStringInput();
+
+    abstract String getTwoDimensionStringInput();
+
+    @Test
+    void decodeItem() {
+        T[] expected = getExpectedSingleDimensionArray();
+        assertThat(codec.decode(getSingleDimensionBinaryArray(), getArrayPostgresqlObjectId().getObjectId(), FORMAT_BINARY, getSingleDimensionArrayType()))
+            .isEqualTo(expected);
+        assertThat(codec.decode(encode(TEST, getSingleDimensionStringInput()), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, getSingleDimensionArrayType()))
+            .isEqualTo(expected);
+    }
+
+    @Test
+    void decodeItem_textArray() {
+        assertThat(codec.decode(encode(TEST, getSingleDimensionStringInput()), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, getSingleDimensionArrayType()))
+            .isEqualTo(getExpectedSingleDimensionArray());
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    void decodeItem_emptyArray() {
+        T[][] empty = (T[][]) new Object[][]{};
+        assertThat(codec.decode(encode(TEST, "{}"), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, getTwoDimensionArrayType()))
+            .isEqualTo(empty);
+    }
+
+    @Test
+    @SuppressWarnings("unchecked")
+    void decodeItem_emptyBinaryArray() {
+        ByteBuf buf = TEST
+            .buffer()
+            .writeInt(0)
+            .writeInt(0)
+            .writeInt(getPostgresqlObjectId().getObjectId());
+
+        T[][] empty = (T[][]) new Object[][]{};
+        assertThat(codec.decode(buf, getArrayPostgresqlObjectId().getObjectId(), FORMAT_BINARY, getTwoDimensionArrayType()))
+            .isEqualTo(empty);
+    }
+
+    @Test
+    void decodeItem_expectedLessDimensionsInArray() {
+        assertThatIllegalArgumentException()
+            .isThrownBy(() -> codec.decode(encode(TEST, "{" + getSingleDimensionStringInput() + "}"), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, getSingleDimensionArrayType()))
+            .withMessage("Dimensions mismatch: 1 expected, but 2 returned from DB");
+    }
+
+    @Test
+    void decodeItem_expectedLessDimensionsInBinaryArray() {
+        assertThatIllegalArgumentException()
+            .isThrownBy(() -> codec.decode(getTwoDimensionBinaryArray(), getArrayPostgresqlObjectId().getObjectId(), FORMAT_BINARY, getSingleDimensionArrayType()))
+            .withMessage("Dimensions mismatch: 1 expected, but 2 returned from DB");
+    }
+
+    @Test
+    void decodeItem_expectedMoreDimensionsInArray() {
+        assertThatIllegalArgumentException()
+            .isThrownBy(() -> codec.decode(encode(TEST, getSingleDimensionStringInput()), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, getTwoDimensionArrayType()))
+            .withMessage("Dimensions mismatch: 2 expected, but 1 returned from DB");
+    }
+
+    @Test
+    void decodeItem_expectedMoreDimensionsInBinaryArray() {
+        assertThatIllegalArgumentException()
+            .isThrownBy(() -> codec.decode(getSingleDimensionBinaryArray(), getArrayPostgresqlObjectId().getObjectId(), FORMAT_BINARY, getTwoDimensionArrayType()))
+            .withMessage("Dimensions mismatch: 2 expected, but 1 returned from DB");
+    }
+
+    @Test
+    void decodeItem_twoDimensionalArrayWithNull() {
+        assertThat(codec.decode(encode(TEST, getTwoDimensionStringInput()), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, getTwoDimensionArrayType()))
+            .isEqualTo(getExpectedTwoDimensionArray());
+    }
+
+    @Test
+    void decodeItem_twoDimensionalBinaryArrayWithNull() {
+        assertThat(codec.decode(getTwoDimensionBinaryArray(), getArrayPostgresqlObjectId().getObjectId(), FORMAT_BINARY, getTwoDimensionArrayType()))
+            .isEqualTo(getExpectedTwoDimensionArray());
+    }
+
+    @Test
+    @SuppressWarnings({"rawtypes", "unchecked"})
+    void decodeObject() {
+        Codec genericCodec = codec;
+        assertThat(genericCodec.canDecode(getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, Object.class)).isTrue();
+        T[] expected = getExpectedSingleDimensionArray();
+
+        assertThat(genericCodec.decode(getSingleDimensionBinaryArray(), getArrayPostgresqlObjectId().getObjectId(), FORMAT_BINARY, Object.class))
+            .isEqualTo(expected);
+        assertThat(genericCodec.decode(encode(TEST, getSingleDimensionStringInput()), getArrayPostgresqlObjectId().getObjectId(), FORMAT_TEXT, Object.class))
+            .isEqualTo(expected);
+    }
+
+    @Test
+    void doCanDecode() {
+        assertThat(codec.doCanDecode(getPostgresqlObjectId(), FORMAT_TEXT)).isFalse();
+        assertThat(codec.doCanDecode(getArrayPostgresqlObjectId(), FORMAT_TEXT)).isTrue();
+        assertThat(codec.doCanDecode(getArrayPostgresqlObjectId(), FORMAT_BINARY)).isTrue();
+    }
+
+    @Test
+    void doCanDecodeNoType() {
+        assertThatIllegalArgumentException().isThrownBy(() -> codec.doCanDecode(null, null))
+            .withMessage("type must not be null");
+    }
+
+    @Test
+    void encodeArray() {
+        ParameterAssert.assertThat(codec.encodeArray(() -> encode(TEST, getSingleDimensionStringInput()), getArrayPostgresqlObjectId()))
+            .hasFormat(FORMAT_TEXT)
+            .hasType(getArrayPostgresqlObjectId().getObjectId())
+            .hasValue(encode(TEST, getSingleDimensionStringInput()));
+    }
+
+    @Test
+    void encodeNull() {
+        ParameterAssert.assertThat(codec.encodeNull())
+            .isEqualTo(new EncodedParameter(FORMAT_BINARY, getArrayPostgresqlObjectId().getObjectId(), NULL_VALUE));
+    }
+
+}