milestone 27: diagnostics — operational failures land in one curated log, resolved history purgeable

src/config/import.zig

@@ -151,6 +151,7 @@ fn reportDeletes(diags: *validate.Diagnostics, summary: reconcile.Summary) error
 
 const testing = std.testing;
 const config_schema = @import("../storage/config_schema.zig");
+const export_mod = @import("export.zig");
 const migrations = @import("../storage/migrations.zig");
 
 fn openMigrated() !db.Db {
@@ -282,6 +283,55 @@ test "importSource converges a migrated database and group 'default' keeps id 1"
     );
 }
 
+test "an export and re-import leaves the operational_events log untouched" {
+    // `operational_events` is runtime state, not configuration: it is out of
+    // `table_names` and out of `delete_order`, so an export must not emit it and
+    // an import's wipe must not reach it. A diagnostics log destroyed by a
+    // routine `nxdns import` would take the record of what the box has been
+    // doing with it.
+    var threaded: std.Io.Threaded = .init(testing.allocator, .{});
+    defer threaded.deinit();
+    const io = threaded.io();
+    const gpa = testing.allocator;
+
+    var database = try openMigrated();
+    defer database.close();
+    try importText(io, &database, full_source, .{});
+    try database.exec(
+        \\INSERT INTO operational_events
+        \\  (code, subject_key, subject_label, severity, first_seen, last_seen, occurrences, resolved_at)
+        \\VALUES ('disk.space', 'data', 'data', 'warning', 100, 200, 3, NULL),
+        \\       ('blocklist.refresh', 'https://a.example', 'A', 'warning', 100, 150, 1, 300);
+    );
+
+    var rendered: std.Io.Writer.Allocating = .init(gpa);
+    defer rendered.deinit();
+    try export_mod.writeToWriter(gpa, &database, &rendered.writer);
+    const source = try gpa.dupeZ(u8, rendered.written());
+    defer gpa.free(source);
+
+    // The export is the whole declared configuration and says nothing about
+    // the log.
+    try testing.expect(!std.mem.containsAtLeast(u8, source, 1, "operational_events"));
+    try testing.expect(!std.mem.containsAtLeast(u8, source, 1, "disk.space"));
+
+    // A round trip is by definition delete-free for the config tables, and the
+    // events survive it untouched, resolved and active alike.
+    try importText(io, &database, source, .{ .allow_delete = true });
+    var stmt = try database.prepare(
+        "SELECT code, occurrences, resolved_at FROM operational_events ORDER BY id",
+    );
+    defer stmt.deinit();
+    try testing.expect(try stmt.step());
+    try testing.expectEqualStrings("disk.space", stmt.columnText(0));
+    try testing.expectEqual(@as(i64, 3), stmt.columnInt(1));
+    try testing.expect(stmt.isNull(2));
+    try testing.expect(try stmt.step());
+    try testing.expectEqualStrings("blocklist.refresh", stmt.columnText(0));
+    try testing.expectEqual(@as(i64, 300), stmt.columnInt(2));
+    try testing.expect(!try stmt.step());
+}
+
 test "an import whose diff deletes rows is refused, names the tables, and changes nothing" {
     // Ruling 6: the emptiness guard is gone, so this is what stops
     // `nxdns import ./wrong.zon` from emptying a configured database.