adjust ALTER COLUMN parsing (#1520)

* add basic TCL tests for ALTER COLUMN libsql feature

* propagate length of the new column definition directly from the parser

- this will allow libsql to automatically handle comment and space characters appended to the column definition

* small formatting fixes

* cargo xtask build-bundled

* add test against sqlite3 source in rust_suite

* fix test in rust_suite

libsql-sqlite3/test/libsql_alter.test

@@ -0,0 +1,54 @@
+set testdir [file dirname $argv0]
+
+source $testdir/tester.tcl
+
+# Test Organisation:
+# ------------------
+#
+# libsql_alter-ok.*: Test that ALTER COLUMN correctly modifies the CREATE TABLE sql.
+# libsql_alter-err.*: Test error messages.
+#
+
+do_test libsql_alter-ok.1 {
+  execsql {CREATE TABLE t1(x);}
+  execsql {ALTER TABLE t1 ALTER COLUMN x TO x;}
+  execsql {SELECT sql FROM sqlite_master WHERE tbl_name = 't1';}
+} {{CREATE TABLE t1(x)}}
+
+do_test libsql_alter-ok.2 {
+  execsql {CREATE TABLE t2(x);}
+  execsql {ALTER TABLE t2 ALTER COLUMN x TO x INTEGER DEFAULT(-1);}
+  execsql {SELECT sql FROM sqlite_master WHERE tbl_name = 't2';}
+} {{CREATE TABLE t2(x INTEGER DEFAULT(-1))}}
+
+do_test libsql_alter-ok.3 {
+  execsql {CREATE TABLE t3(x);}
+  # NOTE: extra spaces in the end of ALTER COLUMN command
+  execsql { ALTER TABLE t3 ALTER COLUMN x TO x INTEGER DEFAULT(-1);   }
+  execsql {SELECT sql FROM sqlite_master WHERE tbl_name = 't3';}
+} {{CREATE TABLE t3(x INTEGER DEFAULT(-1))}}
+
+do_test libsql_alter-ok.4 {
+  execsql {CREATE TABLE t4(x);}
+  execsql { ALTER TABLE t4 ALTER COLUMN x TO x INTEGER DEFAULT(-1); -- explain alter command }
+  execsql {SELECT sql FROM sqlite_master WHERE tbl_name = 't4';}
+} {{CREATE TABLE t4(x INTEGER DEFAULT(-1))}}
+
+reset_db
+do_test libsql_alter-err.1 {
+  execsql { CREATE TABLE t1(x); }
+  catchsql { ALTER TABLE t1 ALTER COLUMN x TO x PRIMARY KEY; }
+} {1 {error in adding x PRIMARY KEY to t1: PRIMARY KEY constraint cannot be altered}}
+
+do_test libsql_alter-err.2 {
+  execsql { CREATE TABLE t2(x); }
+  catchsql { ALTER TABLE t2 ALTER COLUMN x TO x INTEGER UNIQUE; }
+} {1 {error in adding x INTEGER UNIQUE to t2: UNIQUE constraint cannot be altered}}
+
+do_test libsql_alter-err.3 {
+  execsql { CREATE TABLE t3(x, y); }
+  catchsql { ALTER TABLE t3 ALTER COLUMN y TO y GENERATED ALWAYS AS (2 * x) VIRTUAL; }
+} {1 {error in adding y GENERATED ALWAYS AS (2 * x) VIRTUAL to t3: GENERATED constraint cannot be altered}}
+
+finish_test
+

libsql-sqlite3/test/rust_suite/src/alter_column.rs

@@ -184,3 +184,15 @@ fn test_update_view_forbidden() {
         .execute("ALTER TABLE v ALTER COLUMN id TO id", ())
         .is_err());
 }
+
+#[test]
+fn test_comment_in_the_end() {
+    let conn = Connection::open_in_memory().unwrap();
+
+    conn.execute("CREATE TABLE t(id)", ()).unwrap();
+    conn.execute(
+        "ALTER TABLE t ALTER COLUMN id TO id CHECK(id < 5); -- explanation for alter command ",
+        (),
+    )
+    .unwrap();
+}