Drop function if already exists and conflict

src/main/kotlin/fr/postgresjson/migration/Function.kt

@@ -1,9 +1,11 @@
 package fr.postgresjson.migration
 
+import com.github.jasync.sql.db.postgresql.exceptions.GenericDatabaseException
 import fr.postgresjson.connexion.Connection
 import fr.postgresjson.migration.Migration.Action
 import fr.postgresjson.migration.Migration.Status
 import java.util.*
+import java.util.concurrent.CompletionException
 import fr.postgresjson.definition.Function as DefinitionFunction
 
 data class Function(
@@ -34,7 +36,15 @@ data class Function(
     )
 
     override fun up(): Status {
-        connection.sendQuery(up.script)
+        try {
+            connection.sendQuery(up.script)
+        } catch (e: CompletionException) {
+            val cause = e.cause
+            if (cause is GenericDatabaseException && cause.errorMessage.fields['C'] == "42P13") {
+                connection.sendQuery("drop function ${down.getDefinition()}")
+                connection.sendQuery(up.script)
+            }
+        }
 
         this::class.java.classLoader.getResource("sql/migration/insertFunction.sql")!!.readText().let {
             connection.selectOne<MigrationEntity>(it, listOf(up.name, up.getDefinition(), up.script, down.script))?.let { function ->

src/main/kotlin/fr/postgresjson/migration/Migrations.kt

@@ -137,7 +137,8 @@ data class Migrations private constructor(
     fun addFunction(newDefinition: DefinitionFunction, callback: (Function) -> Unit = {}): Migrations {
         val currentFunction = functions[newDefinition.name]
         if (currentFunction === null || currentFunction `is different from` newDefinition) {
-            functions[newDefinition.name] = Function(newDefinition, newDefinition, connection).apply {
+            val oldDefinition = functions[newDefinition.name]?.up ?: newDefinition
+            functions[newDefinition.name] = Function(newDefinition, oldDefinition, connection).apply {
                 doExecute = Action.UP
             }
         } else {

src/test/kotlin/fr/postgresjson/MigrationTest.kt

@@ -79,7 +79,7 @@ class MigrationTest(): TestAbstract() {
     @Test
     fun `run migrations force down`() {
         val resources = File(this::class.java.getResource("/sql/real_migrations").toURI())
-        val resourcesFunctions = File(this::class.java.getResource("/sql/function").toURI())
+        val resourcesFunctions = File(this::class.java.getResource("/sql/function/Test").toURI())
         Migrations(listOf(resources, resourcesFunctions), connection).apply {
             up().apply {
                 size `should be equal to` 6
@@ -94,7 +94,7 @@ class MigrationTest(): TestAbstract() {
 
     @Test
     fun `run functions migrations`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         Migrations(resources, connection).apply {
             run().size `should be equal to` 5
         }
@@ -107,4 +107,26 @@ class MigrationTest(): TestAbstract() {
         Assertions.assertEquals(objTest!!.id, 3)
         Assertions.assertEquals(objTest.name, "test")
     }
+
+    @Test
+    fun `run functions migrations and drop if exist`() {
+        val resources = File(this::class.java.getResource("/sql/function/Test1").toURI())
+        Migrations(resources, connection).apply {
+            run().size `should be equal to` 1
+        }
+
+        val objTest: RequesterTest.ObjTest? = Requester(connection)
+            .addFunction(resources)
+            .getFunction("test_function_duplicate")
+            .selectOne(listOf("test"))
+
+        Assertions.assertEquals(objTest!!.id, 3)
+        Assertions.assertEquals(objTest.name, "test")
+
+
+        val resources2 = File(this::class.java.getResource("/sql/function/Test2").toURI())
+        Migrations(resources2, connection).apply {
+            run().size `should be equal to` 1
+        }
+    }
 }

src/test/kotlin/fr/postgresjson/RequesterTest.kt

@@ -25,7 +25,7 @@ class RequesterTest: TestAbstract() {
 
     @Test
     fun `get function from file`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         val objTest: ObjTest? = Requester(connection)
             .addFunction(resources)
             .getFunction("test_function")
@@ -48,7 +48,7 @@ class RequesterTest: TestAbstract() {
 
     @Test
     fun `call exec on function`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         val result = Requester(connection)
             .addFunction(resources)
             .getFunction("test_function")
@@ -70,7 +70,7 @@ class RequesterTest: TestAbstract() {
 
     @Test
     fun `call sendQuery on function`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         val result = Requester(connection)
             .addFunction(resources)
             .getFunction("function_void")
@@ -81,7 +81,7 @@ class RequesterTest: TestAbstract() {
 
     @Test
     fun `call selectOne on function`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         val obj: ObjTest = Requester(connection)
             .addFunction(resources)
             .getFunction("test_function")
@@ -92,7 +92,7 @@ class RequesterTest: TestAbstract() {
 
     @Test
     fun `call selectOne on function with object`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         val obj2 = ObjTest("original")
         val obj: ObjTest = Requester(connection)
             .addFunction(resources)
@@ -116,7 +116,7 @@ class RequesterTest: TestAbstract() {
 
     @Test
     fun `call select (multiple) on function`() {
-        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val resources = File(this::class.java.getResource("/sql/function/Test").toURI())
         val obj: List<ObjTest>? = Requester(connection)
             .addFunction(resources)
             .getFunction("test_function_multiple")

src/test/kotlin/fr/postgresjson/TestAbstract.kt

@@ -9,7 +9,7 @@ import java.io.File
 
 @TestInstance(PER_CLASS)
 abstract class TestAbstract {
-    protected val connection = Connection(database = "test", username = "test", password = "test")
+    protected val connection = Connection(database = "test_json", username = "test", password = "test")
 
     @BeforeEach
     fun beforeAll() {

src/test/resources/sql/function/Test1/function_test_duplicate.sql

@@ -0,0 +1,8 @@
+CREATE OR REPLACE FUNCTION test_function_duplicate (name text default 'plop', out result json)
+LANGUAGE plpgsql
+AS
+$$
+BEGIN
+    result = json_build_object('id', 3, 'name', name);
+END;
+$$

src/test/resources/sql/function/Test2/function_test_duplicate.sql

@@ -0,0 +1,8 @@
+CREATE OR REPLACE FUNCTION test_function_duplicate (name text default 'plop') returns text
+    LANGUAGE plpgsql
+AS
+$$
+BEGIN
+    return name;
+END;
+$$