Add tests for the permission serializer and deserializer

app/src/test/java/com/greenart7c3/nostrsigner/models/PermissionTest.kt

@@ -0,0 +1,85 @@
+package com.greenart7c3.nostrsigner.models
+
+import com.fasterxml.jackson.module.kotlin.readValue
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class PermissionTest {
+
+    @Test
+    fun `serializes type and kind`() {
+        val json = Permission.mapper.writeValueAsString(Permission("sign_event", 22242))
+        assertEquals("""{"type":"sign_event","kind":22242}""", json)
+    }
+
+    @Test
+    fun `omits kind when null`() {
+        val json = Permission.mapper.writeValueAsString(Permission("connect", null))
+        assertEquals("""{"type":"connect"}""", json)
+    }
+
+    @Test
+    fun `does not serialize the checked flag`() {
+        val json = Permission.mapper.writeValueAsString(Permission("sign_event", 1, checked = false))
+        assertEquals("""{"type":"sign_event","kind":1}""", json)
+    }
+
+    @Test
+    fun `deserializes type and kind`() {
+        val permission = Permission.mapper.readValue<Permission>("""{"type":"sign_event","kind":22242}""")
+        assertEquals(Permission("sign_event", 22242), permission)
+        assertTrue(permission.checked)
+    }
+
+    @Test
+    fun `deserializes missing kind as null`() {
+        val permission = Permission.mapper.readValue<Permission>("""{"type":"connect"}""")
+        assertEquals("connect", permission.type)
+        assertNull(permission.kind)
+        assertTrue(permission.checked)
+    }
+
+    @Test
+    fun `deserializes explicit null kind as null`() {
+        val permission = Permission.mapper.readValue<Permission>("""{"type":"connect","kind":null}""")
+        assertEquals(Permission("connect", null), permission)
+    }
+
+    @Test
+    fun `ignores unknown fields`() {
+        val permission = Permission.mapper.readValue<Permission>("""{"type":"connect","extra":"ignored"}""")
+        assertEquals(Permission("connect", null), permission)
+    }
+
+    @Test
+    fun `parses kind given as a string of digits`() {
+        val permission = Permission.mapper.readValue<Permission>("""{"type":"sign_event","kind":"22242"}""")
+        assertEquals(Permission("sign_event", 22242), permission)
+    }
+
+    @Test
+    fun `falls back to null kind for non numeric kind`() {
+        val permission = Permission.mapper.readValue<Permission>("""{"type":"sign_event","kind":"abc"}""")
+        assertEquals(Permission("sign_event", null), permission)
+    }
+
+    @Test
+    fun `round trips a list of permissions`() {
+        val permissions = listOf(
+            Permission("sign_event", 22242),
+            Permission("connect", null),
+            Permission("nip04_encrypt", null, checked = false),
+        )
+
+        val json = Permission.mapper.writeValueAsString(permissions)
+        val parsed = Permission.mapper.readValue<MutableList<Permission>>(json)
+
+        assertEquals(
+            listOf("sign_event" to 22242, "connect" to null, "nip04_encrypt" to null),
+            parsed.map { it.type to it.kind },
+        )
+        assertTrue(parsed.all { it.checked })
+    }
+}