atproto utils for zig
zat.dev
atproto
sdk
zig
feat: extractAt ignores unknown JSON fields by default
enables partial extraction from JSON with extra fields, which is common
when parsing external API responses (e.g., TAP firehose messages have
live, rev, cid fields we don't need).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
+36
-1
+36
-1
src/internal/json.zig
+36
-1
src/internal/json.zig
···
125
125
},
126
126
};
127
127
}
128
-
return std.json.parseFromValueLeaky(T, allocator, current, .{}) catch |err| {
128
+
return std.json.parseFromValueLeaky(T, allocator, current, .{ .ignore_unknown_fields = true }) catch |err| {
129
129
log.debug("extractAt: parse failed for {s} at path {any}: {s} (json type: {s})", .{
130
130
@typeName(T),
131
131
path,
···
347
347
const result = extractAtOptional(Thing, arena.allocator(), parsed.value, .{ "data", "missing" });
348
348
try std.testing.expect(result == null);
349
349
}
350
+
351
+
test "extractAt ignores unknown fields" {
352
+
// real-world case: TAP messages have extra fields (live, rev, cid) that we don't need
353
+
const json_str =
354
+
\\{
355
+
\\ "record": {
356
+
\\ "live": true,
357
+
\\ "did": "did:plc:abc123",
358
+
\\ "rev": "3mbspmpaidl2a",
359
+
\\ "collection": "pub.leaflet.document",
360
+
\\ "rkey": "xyz789",
361
+
\\ "action": "create",
362
+
\\ "cid": "bafyreitest"
363
+
\\ }
364
+
\\}
365
+
;
366
+
var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
367
+
defer arena.deinit();
368
+
369
+
const parsed = try std.json.parseFromSlice(std.json.Value, arena.allocator(), json_str, .{});
370
+
371
+
// only extract the fields we care about
372
+
const Record = struct {
373
+
collection: []const u8,
374
+
action: []const u8,
375
+
did: []const u8,
376
+
rkey: []const u8,
377
+
};
378
+
379
+
const rec = try extractAt(Record, arena.allocator(), parsed.value, .{"record"});
380
+
try std.testing.expectEqualStrings("pub.leaflet.document", rec.collection);
381
+
try std.testing.expectEqualStrings("create", rec.action);
382
+
try std.testing.expectEqualStrings("did:plc:abc123", rec.did);
383
+
try std.testing.expectEqualStrings("xyz789", rec.rkey);
384
+
}