test: cover REPL script execution

src/test/kotlin/kestrel/ReplTest.kt

@@ -0,0 +1,57 @@
+package kestrel
+
+import kestrel.cli.Repl
+import kotlin.test.Test
+import kotlin.test.assertContains
+import kotlin.test.assertTrue
+
+class ReplTest {
+    private fun runScript(script: String): String {
+        val output = StringBuilder()
+        Repl(output, output).run(script.reader().buffered())
+        return output.toString()
+    }
+
+    @Test
+    fun gateScenarioRendersOrderedResult() {
+        val script = """
+            CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT NOT NULL, age INTEGER);
+            INSERT INTO users VALUES (1, 'ada', 36), (2, 'linus', 54), (3, 'grace', 85);
+            SELECT name, age FROM users WHERE age > 40 ORDER BY age DESC;
+        """.trimIndent()
+        val output = runScript(script)
+        assertContains(output, "3 rows inserted")
+        assertContains(output, "grace")
+        assertContains(output, "linus")
+        assertTrue(output.indexOf("grace") < output.indexOf("linus"), "grace should be listed before linus")
+    }
+
+    @Test
+    fun metaTablesListsCreatedTables() {
+        val output = runScript("CREATE TABLE alpha (id INTEGER);\nCREATE TABLE beta (id INTEGER);\n.tables\n")
+        assertContains(output, "alpha")
+        assertContains(output, "beta")
+    }
+
+    @Test
+    fun metaSchemaPrintsDefinition() {
+        val output = runScript("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT NOT NULL);\n.schema users\n")
+        assertContains(output, "CREATE TABLE users")
+        assertContains(output, "id INTEGER PRIMARY KEY")
+        assertContains(output, "name TEXT NOT NULL")
+    }
+
+    @Test
+    fun parseErrorIsReportedAndReplContinues() {
+        val output = runScript("SELCT bad;\nCREATE TABLE t (a INTEGER);\n.tables\n")
+        assertContains(output, "Error:")
+        assertContains(output, "t")
+    }
+
+    @Test
+    fun exitStopsProcessing() {
+        val output = runScript("CREATE TABLE seen (a INTEGER);\n.exit\nCREATE TABLE unseen (a INTEGER);\n")
+        assertContains(output, "Table seen created")
+        assertTrue(!output.contains("unseen"), "statements after .exit must not run")
+    }
+}