Support Arithmetic function ROUND

docs/en/jpql-with-kotlin-jdsl/expressions.md

@@ -203,6 +203,11 @@ Kotlin JDSL provides a series of functions to support built-in functions in JPA.
 | LOCATE    | support      |
 
 ### Arithmetic functions
+* round
+
+```kotlin
+round(path(Book::price), Expressions.value(Int::class))
+```
 
 | Function | DSL function |
 |----------|--------------|
@@ -213,7 +218,6 @@ Kotlin JDSL provides a series of functions to support built-in functions in JPA.
 | LN       | not yet      |
 | MOD      | not yet      |
 | POWER    | not yet      |
-| ROUND    | not yet      |
 | SIGN     | not yet      |
 | SQRT     | not yet      |
 | SIZE     | not yet      |

docs/ko/jpql-with-kotlin-jdsl/expressions.md

@@ -201,6 +201,11 @@ Kotlin JDSL은 JPA에서 제공하는 여러 함수들을 지원하기 위함 
 | LOCATE    | support      |
 
 ### Arithmetic functions
+* round
+
+```kotlin
+round(path(Book::price), Expressions.value(Int::class))
+```
 
 | Function | DSL function |
 |----------|--------------|
@@ -211,7 +216,6 @@ Kotlin JDSL은 JPA에서 제공하는 여러 함수들을 지원하기 위함 
 | LN       | not yet      |
 | MOD      | not yet      |
 | POWER    | not yet      |
-| ROUND    | not yet      |
 | SIGN     | not yet      |
 | SQRT     | not yet      |
 | SIZE     | not yet      |

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

@@ -366,6 +366,22 @@ open class Jpql : JpqlDsl {
         )
     }
 
+    /**
+     * Creates an expression that represents the rounding of the specified property's value to a specified scale.
+     */
+    @SinceJdsl("3.4.0")
+    fun <T : Any, V : Number> round(expr: KProperty1<T, @Exact V>, scale: Expression<Int>): Expression<Double> {
+        return Expressions.round(Paths.path(expr), scale.toExpression())
+    }
+
+    /**
+     * Creates an expression that represents the rounding of the specified property's value to a specified scale.
+     */
+    @SinceJdsl("3.4.0")
+    fun <T : Number> round(value: Expressionable<T>, scale: Expressionable<Int>): Expression<Double> {
+        return Expressions.round(value.toExpression(), scale.toExpression())
+    }
+
     /**
      * Creates an expression that represents the plus of values.
      *

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

@@ -0,0 +1,51 @@
+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
+
+class RoundDslTest : WithAssertions {
+    private val expression1 = Paths.path(Book::salePrice)
+    private val intExpression1: Expression<Int> = Expressions.value(3)
+    private val int1 = 3
+
+    @Test
+    fun `round() with a expression`() {
+        // when
+        val expression = queryPart {
+            round(expression1, intExpression1)
+        }.toExpression()
+
+        val actual: Expression<Double> = expression // for type check
+
+        // then
+        val expected = Expressions.round(
+            value = expression1,
+            scale = intExpression1,
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+
+    @Test
+    fun `round() with a property`() {
+        // when
+        val expression = queryPart {
+            round(Book::price, intExpression1)
+        }.toExpression()
+
+        val actual: Expression<Double> = expression // for type check
+
+        // then
+        val expected = Expressions.round(
+            value = Paths.path(Book::price),
+            scale = Expressions.value(int1),
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+}

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

@@ -38,6 +38,7 @@ import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlTrimLeading
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlTrimTrailing
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlUpper
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlValue
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlRound
 import com.linecorp.kotlinjdsl.querymodel.jpql.path.Path
 import com.linecorp.kotlinjdsl.querymodel.jpql.predicate.Predicate
 import com.linecorp.kotlinjdsl.querymodel.jpql.select.SelectQuery
@@ -246,6 +247,14 @@ object Expressions {
         return JpqlAvg(distinct, expr)
     }
 
+    /**
+     * Creates an expression that represents the rounding of the specified property's value to a specified scale.
+     */
+    @SinceJdsl("3.4.0")
+    fun <T : Number> round(value: Expression<T>, scale: Expression<Int>): Expression<Double> {
+        return JpqlRound(value, scale)
+    }
+
     /**
      * Creates an expression that represents the sum of values.
      *

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

@@ -0,0 +1,14 @@
+package com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl
+
+import com.linecorp.kotlinjdsl.Internal
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expression
+
+/**
+ * Expression that calculates the rounding of a numeric [value] to a specified [scale].
+ */
+@Internal
+data class JpqlRound<T: Number> internal constructor(
+    val value: Expression<T>,
+    val scale: Expression<Int>,
+) : Expression<Double> {
+}

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

@@ -30,6 +30,7 @@ import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlNullIf
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlParam
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlPathType
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlPlus
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlRound
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlSubquery
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlSubstring
 import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlSum
@@ -392,6 +393,20 @@ class ExpressionsTest : WithAssertions {
         assertThat(actual).isEqualTo(expected)
     }
 
+    @Test
+    fun round() {
+        // when
+        val actual = Expressions.round(doubleExpression1, intExpression1)
+
+        // then
+        val expected = JpqlRound(
+            doubleExpression1,
+            intExpression1
+        )
+
+        assertThat(actual).isEqualTo(expected)
+    }
+
     @ParameterizedTest
     @ValueSource(booleans = [true, false])
     fun `sum() with an int expression`(distinct: Boolean) {

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

@@ -93,6 +93,7 @@ import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlPathTreatSerializ
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlPathTypeSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlPlusSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlPredicateParenthesesSerializer
+import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlRoundSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlSelectQuerySerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlSortSerializer
 import com.linecorp.kotlinjdsl.render.jpql.serializer.impl.JpqlSubquerySerializer
@@ -338,6 +339,7 @@ private class DefaultModule : JpqlRenderModule {
             JpqlPathTypeSerializer(),
             JpqlPlusSerializer(),
             JpqlPredicateParenthesesSerializer(),
+            JpqlRoundSerializer(),
             JpqlSelectQuerySerializer(),
             JpqlSortSerializer(),
             JpqlSubquerySerializer(),

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

@@ -0,0 +1,29 @@
+package com.linecorp.kotlinjdsl.render.jpql.serializer.impl
+
+import com.linecorp.kotlinjdsl.Internal
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlRound
+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 JpqlRoundSerializer : JpqlSerializer<JpqlRound<*>>{
+    override fun handledType(): KClass<JpqlRound<*>> {
+        return JpqlRound::class
+    }
+
+    override fun serialize(part: JpqlRound<*>, writer: JpqlWriter, context: RenderContext) {
+        val delegate = context.getValue(JpqlRenderSerializer)
+
+        writer.write("ROUND")
+
+        writer.writeParentheses {
+            delegate.serialize(part.value, writer, context)
+
+            writer.write(", ")
+            delegate.serialize(part.scale, writer, context)
+        }
+    }
+}

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

@@ -0,0 +1,58 @@
+package com.linecorp.kotlinjdsl.render.jpql.serializer.impl
+
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.Expressions
+import com.linecorp.kotlinjdsl.querymodel.jpql.expression.impl.JpqlRound
+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.Assertions.assertThat
+import org.junit.jupiter.api.Test
+
+@JpqlSerializerTest
+class JpqlRoundSerializerTest {
+    private val sut = JpqlRoundSerializer()
+
+    @MockK
+    private lateinit var writer: JpqlWriter
+
+    @MockK
+    private lateinit var serializer: JpqlRenderSerializer
+
+    private val expression1 = Paths.path(Book::price)
+    private val expression2 = Expressions.value(3)
+
+    @Test
+    fun handledType() {
+        // when
+        val actual = sut.handledType()
+
+        // then
+        assertThat(actual).isEqualTo(JpqlRound::class)
+    }
+    @Test
+    fun serialize() {
+        // given
+        val part = Expressions.round(
+            value = expression1,
+            scale = expression2
+        )
+        val context = TestRenderContext(serializer)
+
+        // when
+        sut.serialize(part as JpqlRound<*>, writer, context)
+
+        // then
+        verifySequence {
+            writer.write("ROUND")
+            writer.writeParentheses(any())
+            serializer.serialize(expression1, writer, context)
+            writer.write(", ")
+            serializer.serialize(expression2, writer, context)
+        }
+    }
+}