fix: Apply inProperCase() to CHECK constraint names

[Rashin Arab (rasharab)]

Problem

CHECK constraint names generated for unsigned/signed integer columns (e.g. uinteger(), ushort(), ubyte(), ulong()) use tableNameWithSchemaSanitized, which preserves the raw Kotlin class name casing. On PostgreSQL, unquoted identifiers are folded to lowercase on storage, so mixed-case constraint names in DDL don't match what pg_constraint.conname stores.

For example, uinteger("onboardingStates") on OrgMemberModel generates:

chk_OrgMemberModel_unsigned_integer_onboardingStates

but PostgreSQL stores it as chk_orgmembermodel_unsigned_integer_onboardingstates.

This causes problems for any migration tooling that checks pg_constraint.conname for idempotent IF NOT EXISTS guards — the mixed-case lookup fails to find the existing constraint.

Root Cause

Other constraint types already handle casing correctly:

• FK constraints (ForeignKeyConstraint.fkName, line 118-123): applies cutIfNecessaryAndQuote(...).inProperCase()
• Index names (Index.indexName, line 280-291): applies buildString { ... }.inProperCase()
• CHECK constraints (CheckConstraint.from, line 247): only applies cutIfNecessaryAndQuote(name) — missing .inProperCase()

The CHECK constraint name is built from generatedUnsignedCheckPrefix / generatedSignedCheckPrefix, which use tableNameWithSchemaSanitized (raw tableName.unquoted()) without any casing normalization.

Fix

Apply .inProperCase() to the CHECK constraint name in CheckConstraint.from(), matching the pattern already used for FK and Index constraints:

// Before
CheckConstraint(tableName, identifierManager.cutIfNecessaryAndQuote(name), checkOpSQL)

// After  
CheckConstraint(tableName, identifierManager.cutIfNecessaryAndQuote(name).inProperCase(), checkOpSQL)

Also added a test with a mixed-case table name (MixedCaseUIntTable) that verifies the CHECK constraint name uses inProperCase(). Test passes on H2 (uppercase) and will pass on PostgreSQL (lowercase).

Fixes #2825

[Rashin Arab (rasharab)]

Chantal Loncle (@bog-walk) Can you take a look and see if this is okay (when you have time)?

[Chantal Loncle (bog-walk)]

Hi Rashin Arab (@rasharab) and thanks for catching this naming convention inconsistency. It's looking good to me so far. I was initially concerned that, while this may not be a breaking API change, that it might technically count as a behavioural breaking change. So I'm running regression tests, which so far seem to all be passing.

If you are able to, please add something like the following, to simulate a case where the user previously created a database table using the old check constraint name. In both exposed-migration-jdbc and exposed-migration-r2dbc DatabaseMigrationTests.kt. To ensure that this naming change will not trigger migration statements, for example:

@OptIn(InternalApi::class)
@Test
fun testUnsignedCheckConstraintNameCaseRegression() {
    withDb(excludeSettings = TestDB.ALL_MYSQL_MARIADB) {
        val previousConstraintName = "chk_MixedCaseUInt_unsigned_integer_unsignedCol"
        val currentDdl = MixedCaseUIntTable.createStatement().single()
        val currentCheckClause = currentDdl.substringAfter("CHECK ")
        val previousDdl = "${currentDdl.substringBefore(" CONSTRAINT ")} CONSTRAINT $previousConstraintName CHECK $currentCheckClause"

        try {
            exec(previousDdl)
            commit()

            val rerun = MigrationUtils.statementsRequiredForDatabaseMigration(MixedCaseUIntTable, withLogs = false)
            assertTrue(rerun.isEmpty())
        } finally {
            SchemaUtils.drop(MixedCaseUIntTable)
        }
    }
}

Lastly, unfortunately our GH <-> TC (CI/CD) integration is not currently working, so there are some failing tests that are not visible to you as part of the PR workflow. These are any tests that test directly for generated SQL using hard-coded strings. Please do a project search for the following tests and add .inProperCase() to the plain string constraint names:

• testDefaults01() [the datetime ones across multiple test modules]
• testTimestampWithTimeZoneDefaults()
• testCustomCheckConstraintName() <-- feel free to add @Suppress("MaximumLineLength") to avoid any detekt issues here

Edit: It's actually many many failing tests. Basically anywhere that you find a hard-coded " CONSTRAINT " in a test assert, would need to have the name chained with .inProperCase().

Let me know if anything else doesn't work or is causing problems for you.

[Chantal Loncle (bog-walk)]

Please simplify this with:

withTables(excludeSettings = TestDB.ALL_MYSQL_MARIADB, MixedCaseUIntTable) {
    val checkConstraints = MixedCaseUIntTable.checkConstraints()
    ...
}

Please also copy this test over to the same file/location in exposed-r2dbc-tests.