package com.peachpasswords.sync

import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Test

/** Pure failure-injection coverage for the real SharedPreferences transaction helper. */
class RegistryTransactionTest {
    @Test
    fun failed_forward_commit_explicitly_restores_prior_state() {
        var state = "prior"
        val writes = mutableListOf<String>()

        val applied = commitWithRollback("prior", "next", commit = { candidate ->
            writes += candidate
            state = candidate
            candidate != "next"
        })

        assertFalse(applied)
        assertEquals("prior", state)
        assertEquals(listOf("next", "prior"), writes)
    }

    @Test
    fun successful_forward_commit_does_not_run_rollback() {
        var state = "prior"
        val writes = mutableListOf<String>()

        val applied = commitWithRollback("prior", "next", commit = { candidate ->
            writes += candidate
            state = candidate
            true
        })

        assertTrue(applied)
        assertEquals("next", state)
        assertEquals(listOf("next"), writes)
    }
}