milestone 21: abp list exceptions and a regex rule kind

src/web/handlers/rules.zig

@@ -39,7 +39,7 @@ const Created = union(enum) { id: i64, fail: Failure };
 /// not understood.
 fn toInput(body: Body) union(enum) { input: rules_repo.RuleInput, fail: Failure } {
     const kind = model.RuleKind.fromDb(body.kind) orelse
-        return .{ .fail = .{ .invalid = "kind must be 'exact' or 'wildcard'" } };
+        return .{ .fail = .{ .invalid = "kind must be 'exact', 'wildcard' or 'regex'" } };
     const action = model.RuleAction.fromDb(body.action) orelse
         return .{ .fail = .{ .invalid = "action must be 'allow' or 'block'" } };
     return .{ .input = .{
@@ -308,7 +308,7 @@ test "an unknown kind or action is a 400 before anything is written" {
     try testing.expect(toInput(.{
         .group_id = 1,
         .pattern = "ads.example",
-        .kind = "regex",
+        .kind = "glob",
         .action = "block",
     }).fail == .invalid);
 
@@ -327,4 +327,46 @@ test "an unknown kind or action is a 400 before anything is written" {
     });
     try testing.expectEqual(model.RuleKind.wildcard, good.input.kind);
     try testing.expectEqual(model.RuleAction.allow, good.input.action);
+
+    const third = toInput(.{
+        .group_id = 1,
+        .pattern = "^ad[0-9]+-",
+        .kind = "regex",
+        .action = "block",
+    });
+    try testing.expectEqual(model.RuleKind.regex, third.input.kind);
+}
+
+test "a regex rule is stored, and a pattern the engine refuses is a 400 that names it" {
+    var bench: mutations.Bench = undefined;
+    try bench.init(testing.allocator);
+    defer bench.deinit(testing.allocator);
+
+    const created = try applyCreate(&bench.state, bench.io(), bench.arena(), .{
+        .group_id = 1,
+        .pattern = "^ad[0-9]+-",
+        .kind = .regex,
+        .action = .block,
+    });
+    const row = (try rules_repo.getRule(&bench.database, bench.arena(), created.id)).?;
+    try testing.expectEqual(model.RuleKind.regex, row.kind);
+    // Stored verbatim: a regex is not a name, so nothing lowercases or
+    // dot-strips it on the way to the table.
+    try testing.expectEqualStrings("^ad[0-9]+-", row.pattern);
+
+    const unclosed = try applyCreate(&bench.state, bench.io(), bench.arena(), .{
+        .group_id = 1,
+        .pattern = "(",
+        .kind = .regex,
+        .action = .block,
+    });
+    try testing.expectEqualStrings(
+        "rules[0].pattern: '(' is not a valid regex pattern",
+        unclosed.fail.invalid,
+    );
+
+    // The refused pattern reached no table, and the good one is still the only
+    // row: a 400 costs no write and no reload.
+    try testing.expectEqual(@as(i64, 1), try bench.queryInt("SELECT count(*) FROM rules"));
+    try testing.expectEqual(@as(usize, 1), bench.reloads);
 }