milestone 21: abp list exceptions and a regex rule kind

src/web/handlers/blocklists.zig

@@ -59,6 +59,7 @@ pub const StatusView = struct {
     last_error: []const u8,
     domains: u32,
     wildcards: u32,
+    exceptions: u32,
     skipped_regex: u32,
 
     pub fn from(status: *const manager_mod.SourceStatus) StatusView {
@@ -72,6 +73,7 @@ pub const StatusView = struct {
             .last_error = status.errorText(),
             .domains = status.counts.domains,
             .wildcards = status.counts.wildcards,
+            .exceptions = status.counts.exceptions,
             .skipped_regex = status.counts.skipped_regex,
         };
     }
@@ -317,6 +319,7 @@ test "editing a blocklist keeps the counters the refresh wrote" {
         .last_updated = 1700,
         .domain_count = 42,
         .wildcard_count = 3,
+        .exception_count = 2,
         .skipped_regex_count = 1,
         .checksum = "abc",
     });
@@ -380,7 +383,7 @@ test "a status becomes the flat shape the API answers with" {
     const message = "connection refused";
     @memcpy(status.last_error[0..message.len], message);
     status.last_error_len = message.len;
-    status.counts = .{ .domains = 10, .wildcards = 2, .skipped_regex = 1 };
+    status.counts = .{ .domains = 10, .wildcards = 2, .exceptions = 4, .skipped_regex = 1 };
 
     const view: StatusView = .from(&status);
     try testing.expectEqual(@as(i64, 7), view.id);
@@ -389,4 +392,5 @@ test "a status becomes the flat shape the API answers with" {
     try testing.expectEqualStrings(url, view.url);
     try testing.expectEqualStrings(message, view.last_error);
     try testing.expectEqual(@as(u32, 10), view.domains);
+    try testing.expectEqual(@as(u32, 4), view.exceptions);
 }

src/web/handlers/lookup.zig

@@ -38,6 +38,8 @@ pub const Body = struct {
     reason: []const u8,
     /// The rule or list entry that decided it; "" when nothing matched.
     matched: []const u8,
+    /// The list that decided it, which for `blocklist_exception` is the list
+    /// whose `@@` rule lifted the block rather than one that made it.
     source_url: ?[]const u8,
     safe_search_rewrite: ?[]const u8,
 };
@@ -50,7 +52,8 @@ pub const Result = struct {
     blocked: bool,
     reason: matcher.Reason,
     matched: []const u8,
-    /// `blocklist_sources` row id of the list that matched.
+    /// `blocklist_sources` row id of the list that matched, whether it blocked
+    /// the name or lifted it through an `@@` exception.
     source_id: ?i64,
     safe_search_rewrite: ?[]const u8,
 };

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);
 }