feat: implement floor function expression

dsl/jpql/src/main/kotlin/com/linecorp/kotlinjdsl/dsl/jpql/Jpql.kt

@@ -568,6 +568,22 @@ open class Jpql : JpqlDsl {
         return Expressions.ceiling(value.toExpression())
     }
 
+    /**
+     * Creates an expression that is enclosed in floor
+     */
+    @SinceJdsl("3.4.0")
+    fun <T : Any, V : Number> floor(expr: KProperty1<T, @Exact V>): Expression<V> {
+        return Expressions.floor(Paths.path(expr))
+    }
+
+    /**
+     * Creates an expression that is enclosed in floor
+     */
+    @SinceJdsl("3.4.0")
+    fun <T : Number> floor(value: Expressionable<T>): Expression<T> {
+        return Expressions.floor(value.toExpression())
+    }
+
     /**
      * Creates an expression that represents the count of non-null values.
      *

dsl/jpql/src/test/kotlin/com/linecorp/kotlinjdsl/dsl/jpql/expression/FloorDslTest.kt

@@ -0,0 +1,48 @@
+package com.linecorp.kotlinjdsl.dsl.jpql.expression
+
+import com.linecorp.kotlinjdsl.dsl.jpql.entity.book.Book
+import com.linecorp.kotlinjdsl.dsl.jpql.queryPart
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expression
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expressions
+import com.linecorp.kotlinjdsl.querymodel.jpql.path.Paths
+import org.assertj.core.api.WithAssertions
+import org.junit.jupiter.api.Test
+import java.math.BigDecimal
+
+class FloorDslTest : WithAssertions {
+    private val expression1 = Paths.path(Book::salePrice)
+
+    @Test
+    fun `floor() with a property`() {
+        // when
+        val expression = queryPart {
+            floor(Book::price)
+        }.toExpression()
+
+        val actual: Expression<BigDecimal> = expression // for type check
+
+        // then
+        val expected = Expressions.floor(
+            value = Paths.path(Book::price),
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+
+    @Test
+    fun `floor() with a expression`() {
+        // when
+        val expression = queryPart {
+            floor(expression1)
+        }.toExpression()
+
+        val actual: Expression<BigDecimal> = expression // for type check
+
+        // then
+        val expected = Expressions.floor(
+            value = expression1,
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+}

query-model/jpql/src/main/kotlin/com/linecorp/kotlinjdsl/querymodel/jpql/expression/Expressions.kt

@@ -16,6 +16,7 @@ import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlDivide
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlEntityType
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlExpression
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlExpressionParentheses
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlFloor
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlFunctionExpression
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlLength
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlLiteral
@@ -204,6 +205,14 @@ object Expressions {
         return JpqlCeiling(value)
     }
 
+    /**
+     * Creates an expression that is enclosed in floor
+     */
+    @SinceJdsl("3.4.0")
+    fun <T : Number> floor(value: Expression<T>): Expression<T> {
+        return JpqlFloor(value)
+    }
+
     /**
      * Creates an expression that represents the times of values.
      *

query-model/jpql/src/main/kotlin/com/linecorp/kotlinjdsl/querymodel/jpql/expression/impl/JpqlFloor.kt

@@ -0,0 +1,12 @@
+package com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl
+
+import com.linecorp.kotlinjdsl.Internal
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expression
+
+/**
+ * Expression that applies the floor function to [value].
+ */
+@Internal
+data class JpqlFloor<T : Number> internal constructor(
+    val value: Expression<T>,
+) : Expression<T>

query-model/jpql/src/test/kotlin/com/linecorp/kotlinjdsl/querymodel/jpql/expression/ExpressionsTest.kt

@@ -18,6 +18,7 @@ import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlDivide
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlEntityType
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlExpression
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlExpressionParentheses
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlFloor
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlFunctionExpression
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlLength
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlLiteral
@@ -915,4 +916,17 @@ class ExpressionsTest : WithAssertions {
 
         assertThat(actual).isEqualTo(expected)
     }
+
+    @Test
+    fun floor() {
+        // when
+        val actual = Expressions.floor(doubleExpression1)
+
+        // then
+        val expected = JpqlFloor(
+            doubleExpression1,
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
 }

render/jpql/src/main/kotlin/com/linecorp/kotlinjdsl/render/jpql/JpqlRenderContext.kt

@@ -39,6 +39,7 @@ import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlEqualSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlExistsSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlExpressionParenthesesSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlExpressionSerializer
+import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlFloorSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlFunctionExpressionSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlFunctionPredicateSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlGreaterThanAllSerializer
@@ -286,6 +287,7 @@ private class DefaultModule : JpqlRenderModule {
             JpqlExistsSerializer(),
             JpqlExpressionParenthesesSerializer(),
             JpqlExpressionSerializer(),
+            JpqlFloorSerializer(),
             JpqlFunctionExpressionSerializer(),
             JpqlFunctionPredicateSerializer(),
             JpqlGreaterThanAllSerializer(),

render/jpql/src/main/kotlin/com/linecorp/kotlinjdsl/render/jpql/serializer/impl/JpqlFloorSerializer.kt

@@ -0,0 +1,26 @@
+package com.linecorp.kotlinjdsl.render.jpql.serializer.impl
+
+import com.linecorp.kotlinjdsl.Internal
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlFloor
+import com.linecorp.kotlinjdsl.render.RenderContext
+import com.linecorp.kotlinjdsl.render.jpql.serializer.JpqlRenderSerializer
+import com.linecorp.kotlinjdsl.render.jpql.serializer.JpqlSerializer
+import com.linecorp.kotlinjdsl.render.jpql.writer.JpqlWriter
+import kotlin.reflect.KClass
+
+@Internal
+class JpqlFloorSerializer : JpqlSerializer<JpqlFloor<*>> {
+    override fun handledType(): KClass<JpqlFloor<*>> {
+        return JpqlFloor::class
+    }
+
+    override fun serialize(part: JpqlFloor<*>, writer: JpqlWriter, context: RenderContext) {
+        val delegate = context.getValue(JpqlRenderSerializer)
+
+        writer.write("FLOOR")
+
+        writer.writeParentheses {
+            delegate.serialize(part.value, writer, context)
+        }
+    }
+}

render/jpql/src/test/kotlin/com/linecorp/kotlinjdsl/render/jpql/serializer/impl/JpqlFloorSerializerTest.kt

@@ -0,0 +1,55 @@
+package com.linecorp.kotlinjdsl.render.jpql.serializer.impl
+
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expressions
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlFloor
+import com.linecorp.kotlinjdsl.querymodel.jpql.path.Paths
+import com.linecorp.kotlinjdsl.render.TestRenderContext
+import com.linecorp.kotlinjdsl.render.jpql.entity.book.Book
+import com.linecorp.kotlinjdsl.render.jpql.serializer.JpqlRenderSerializer
+import com.linecorp.kotlinjdsl.render.jpql.serializer.JpqlSerializerTest
+import com.linecorp.kotlinjdsl.render.jpql.writer.JpqlWriter
+import io.mockk.impl.annotations.MockK
+import io.mockk.verifySequence
+import org.assertj.core.api.WithAssertions
+import org.junit.jupiter.api.Test
+
+@JpqlSerializerTest
+class JpqlFloorSerializerTest : WithAssertions {
+    private val sut = JpqlFloorSerializer()
+
+    @MockK
+    private lateinit var writer: JpqlWriter
+
+    @MockK
+    private lateinit var serializer: JpqlRenderSerializer
+
+    private val expression1 = Paths.path(Book::price)
+
+    @Test
+    fun handledType() {
+        // when
+        val actual = sut.handledType()
+
+        // then
+        assertThat(actual).isEqualTo(JpqlFloor::class)
+    }
+
+    @Test
+    fun serialize() {
+        // given
+        val part = Expressions.floor(
+            value = expression1,
+        )
+        val context = TestRenderContext(serializer)
+
+        // when
+        sut.serialize(part as JpqlFloor<*>, writer, context)
+
+        // then
+        verifySequence {
+            writer.write("FLOOR")
+            writer.writeParentheses(any())
+            serializer.serialize(expression1, writer, context)
+        }
+    }
+}