test: add tests for RANDOM ROWID

The test suite checks whether RANDOM ROWID keywords work
and its input is validated in the parser.

Author: psarna

test/rust_suite/src/lib.rs

@@ -1,3 +1,5 @@
+mod random_rowid;
+
 #[cfg(test)]
 mod tests {
     use rusqlite::Connection;

test/rust_suite/src/random_rowid.rs

@@ -0,0 +1,51 @@
+#[cfg(test)]
+mod tests {
+    use rusqlite::Connection;
+
+    #[test]
+    fn test_random_rowid_distribution() {
+        let conn = Connection::open_in_memory().unwrap();
+
+        conn.execute("CREATE TABLE t(id)", ()).unwrap();
+        conn.execute("CREATE TABLE tr(id) RANDOM ROWID", ())
+            .unwrap();
+        for _ in 1..=1024 {
+            conn.execute("INSERT INTO t(id) VALUES (42)", ()).unwrap();
+            conn.execute("INSERT INTO tr(id) VALUES (42)", ()).unwrap();
+        }
+
+        let seq_rowids: Vec<i64> = conn
+            .prepare("SELECT rowid FROM t")
+            .unwrap()
+            .query_map([], |row| Ok(row.get_unwrap(0)))
+            .unwrap()
+            .map(|r| r.unwrap())
+            .collect();
+        assert_eq!(seq_rowids, (1..=1024_i64).collect::<Vec<i64>>());
+
+        let random_rowids: Vec<i64> = conn
+            .prepare("SELECT rowid FROM tr")
+            .unwrap()
+            .query_map([], |row| Ok(row.get_unwrap(0)))
+            .unwrap()
+            .map(|r| r.unwrap())
+            .collect();
+        // This assertion is technically just probabilistic, but in practice
+        // precise enough to ~never cause false positives
+        assert_ne!(random_rowids, (1..=1024_i64).collect::<Vec<i64>>())
+    }
+
+    #[test]
+    fn test_random_rowid_validate_create() {
+        let conn = Connection::open_in_memory().unwrap();
+
+        for wrong in [
+            "CREATE TABLE t(id) RANDOM ROWID WITHOUT ROWID",
+            "CREATE TABLE t(id int PRIMARY KEY AUTOINCREMENT) RANDOM ROWID",
+            "CREATE TABLE t(id) RANDOM ROW_ID",
+            "CREATE TABLE t(id) RANDO ROWID",
+        ] {
+            assert!(conn.execute(wrong, ()).is_err());
+        }
+    }
+}