Merge pull request #3654 from lightpanda-io/cors-by-default

Enable CORS by default

.github/workflows/e2e-integration-test.yml

@@ -69,7 +69,7 @@ jobs:
       - name: run end to end integration tests
         continue-on-error: true
         run: |
-          ./lightpanda serve --experimental-features cors --http-cache-dir /tmp/lp-cache --http-proxy ${{ secrets.MASSIVE_PROXY_RESIDENTIAL_US }} --log-level error & echo $! > LPD.pid
+          ./lightpanda serve --http-cache-dir /tmp/lp-cache --http-proxy ${{ secrets.MASSIVE_PROXY_RESIDENTIAL_US }} --log-level error & echo $! > LPD.pid
           go run integration/main.go |tee result.log
           kill `cat LPD.pid`
 

.github/workflows/e2e-test.yml

@@ -117,7 +117,7 @@ jobs:
           echo "value=$args" >> "$GITHUB_OUTPUT"
 
       - run: |
-          ./lightpanda serve --experimental-features cors --port 9222 ${{ steps.args.outputs.value }} &
+          ./lightpanda serve --port 9222 ${{ steps.args.outputs.value }} &
 
       - run: |
           go run runner/main.go
@@ -163,7 +163,7 @@ jobs:
       - id: args
         name: build LP args
         run: |
-          args="--experimental-features cors --http-cache-dir /tmp/lp-cache --load-resources worker --load-resources iframe"
+          args="--http-cache-dir /tmp/lp-cache --load-resources worker --load-resources iframe"
           args="$args --protocol cdp --protocol webdriver"
           [ "${{ matrix.robotstxt }}" = "true" ] && args="$args --obey-robots"
           [ "${{ matrix.wba }}" = "true" ] && args="$args --web-bot-auth-key-file private_key.pem"
@@ -227,7 +227,6 @@ jobs:
           exec 3<<< "${{ secrets.WBA_PRIVATE_KEY_PEM }}"
 
           ./lightpanda fetch --dump http://127.0.0.1:8989/ \
-            --experimental-features cors \
             --web-bot-auth-key-file /proc/self/fd/3 \
             --web-bot-auth-keyid ${{ vars.WBA_KEY_ID }} \
             --web-bot-auth-domain ${{ vars.WBA_DOMAIN }}
@@ -251,7 +250,6 @@ jobs:
           exec 3<<< "${{ secrets.WBA_PRIVATE_KEY_PEM }}"
 
           ./lightpanda fetch --dump "http://127.0.0.1:8989/redirect?to=http://127.0.0.1:8990/" \
-            --experimental-features cors \
             --web-bot-auth-key-file /proc/self/fd/3 \
             --web-bot-auth-keyid ${{ vars.WBA_KEY_ID }} \
             --web-bot-auth-domain ${{ vars.WBA_DOMAIN }}
@@ -430,7 +428,7 @@ jobs:
 
       - run: chmod a+x ./lightpanda
 
-      - run: ./lightpanda fetch --experimental-features cors  "https://demo-browser.lightpanda.io/campfire-commerce/"
+      - run: ./lightpanda fetch  "https://demo-browser.lightpanda.io/campfire-commerce/"
 
   agent-deterministic:
     name: agent deterministic replay
@@ -483,7 +481,7 @@ jobs:
 
           jq --version
 
-          timeout 30 ./lightpanda mcp --experimental-features cors > mcp.out <<'JSONRPC'
+          timeout 30 ./lightpanda mcp > mcp.out <<'JSONRPC'
           {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"ci","version":"1.0.0"}}}
           {"jsonrpc":"2.0","method":"notifications/initialized"}
           {"jsonrpc":"2.0","id":2,"method":"tools/list"}

README.md

@@ -258,7 +258,7 @@ Set `LIGHTPANDA_DISABLE_CORE_DUMP` (to any value) to suppress crash core dumps b
 Here are the key features we have implemented.
 For full details, see our [Web Platform Tests results](https://perf.lightpanda.io/wpt).
 
-- [x] CORS (enable with `--experimental-features cors`)
+- [x] CORS
 - [x] HTTP loader ([Libcurl](https://curl.se/libcurl/))
 - [x] HTML parser ([html5ever](https://github.com/servo/html5ever))
 - [x] DOM tree
@@ -421,8 +421,7 @@ zig build -Dwpt_extensions run -- serve \
     --load-resources iframe \
     --load-resources image \
     --load-resources worker \
-    --load-resources stylesheet \
-    --experimental-features cors
+    --load-resources stylesheet
 ```
 
 Then you can start the wptrunner from the demo's clone dir:

src/Config.zig

@@ -239,10 +239,14 @@ pub const LoadResources = packed struct(u4) {
 };
 
 pub const ExperimentalFeatures = packed struct(u2) {
-    cors: bool = false,
+    cors: bool = false, // ignored, kept only for backward compatibility.
     serviceworker: bool = false,
 };
 
+pub const DisabledFeatures = packed struct(u1) {
+    cors: bool = false,
+};
+
 /// Common CLI args.
 const CommonOptions = .{
     .{ .name = "obey_robots", .type = bool },
@@ -283,6 +287,7 @@ const CommonOptions = .{
     .{ .name = "disable_subframes", .type = bool, .deprecated = "subframes are now disabled by default, use \"--load-resources iframe\" to enable" },
     .{ .name = "disable_workers", .type = bool, .deprecated = "workers are now disabled by default, use \"--load-resources worker\" to enable" },
     .{ .name = "enable_external_stylesheets", .type = bool, .deprecated = "use \"--load-resources stylesheet\" to enable" },
+    .{ .name = "disable_features", .type = DisabledFeatures, .default = DisabledFeatures{} },
     .{ .name = "experimental_features", .type = ExperimentalFeatures, .default = ExperimentalFeatures{} },
     .{ .name = "load_resources", .type = LoadResources, .default = LoadResources{} },
     .{ .name = "v8_flags_unsafe", .type = ?[]const u8 },
@@ -552,6 +557,13 @@ pub fn tlsVerifyHost(self: *const Config) bool {
     };
 }
 
+pub fn obeyCors(self: *const Config) bool {
+    return switch (self.mode) {
+        inline .serve, .fetch, .mcp, .agent => |opts| opts.disable_features.cors == false,
+        else => unreachable,
+    };
+}
+
 pub fn obeyRobots(self: *const Config) bool {
     return switch (self.mode) {
         inline .serve, .fetch, .mcp, .agent => |opts| opts.obey_robots,

src/browser/js/Env.zig

@@ -844,6 +844,10 @@ test "Env: Worker context " {
     const frame = try testing.createFrame();
     defer testing.test_session.closeAllPages();
 
+    // Navigate the frame first to avoid CORS blocking request for the worker.
+    try frame.navigate("http://localhost:9582/", .{});
+    try testing.waitForFrame();
+
     const worker = try @import("../webapi/Worker.zig").init("http://localhost:9582/src/browser/tests/testing.js", null, frame);
 
     var ls: js.Local.Scope = undefined;

src/cli.zig

@@ -766,6 +766,8 @@ pub fn Builder(comptime commands: anytype) type {
 
                 break :blk command.options;
             };
+            // toKebabCase walks every byte of every name.
+            @setEvalBranchQuota(50_000);
             iter_args: while (args.next()) |option_name| {
                 inline for (options) |option| {
                     const name = option.name;

src/help.zon

@@ -409,14 +409,15 @@
     \\  --cors-store-entry-limit <INT>
     \\          Maximum number of entries kept in the CorsStore. 0 means no limit.
     \\          Defaults to 1000.
+    \\  --disable-features <FEATURE>
+    \\          Disable a feature that is on by default. Can be passed multiple times.
+    \\          Defaults to none disabled.
+    \\          Allowed values:
+    \\             cors        Skip CORS checks on fetch/XHR requests.
     \\  --experimental-features <FEATURE>
     \\          Enable an experimental, unstable feature. Can be passed multiple times.
     \\          Behavior may change or be removed without notice.
     \\          Defaults to none enabled.
-    \\          Allowed values:
-    \\              cors      Obey CORS (cross-origin resource sharing) checks
-    \\                        on fetch/XHR requests instead of allowing them
-    \\                        unconditionally.
     \\  --load-resources <RESOURCE>
     \\          Sub-resource to actually request. Can be passed multiple times.
     \\          Defaults to requesting none of them.

src/network/HttpClient.zig

@@ -244,7 +244,7 @@ pub fn init(self: *Client, app: *lp.App) !void {
         .serve_mode = config.mode == .serve,
         .obey_robots = config.obeyRobots(),
         .http_version = config.httpVersion(),
-        .obey_cors = config.experimentalFeatures().cors,
+        .obey_cors = config.obeyCors(),
         .robots = .{
             .network = network,
             .single_flight = .init(allocator),

src/testing.zig

@@ -635,9 +635,28 @@ var serve_counts = [_]struct { name: []const u8, count: u32 = 0 }{
     .{ .name = "prescan_module" },
 };
 
+fn origin(req: *std.http.Server.Request) ?[]const u8 {
+    var it = req.iterateHeaders();
+    while (it.next()) |h| {
+        if (std.mem.eql(u8, "origin", h.name)) {
+            return h.value;
+        }
+    }
+
+    return null;
+}
+
 fn testHTTPHandler(req: *std.http.Server.Request) !void {
     const path = req.head.target;
 
+    if (std.mem.eql(u8, path, "/")) {
+        return req.respond("<html><head></head><body></body></html>", .{
+            .extra_headers = &.{
+                .{ .name = "Content-Type", .value = "text/html; charset=utf-8" },
+            },
+        });
+    }
+
     if (std.mem.eql(u8, path, "/xhr")) {
         return req.respond("1234567890" ** 10, .{
             .extra_headers = &.{
@@ -1155,6 +1174,7 @@ fn testHTTPHandler(req: *std.http.Server.Request) !void {
         return req.respond(html, .{
             .extra_headers = &.{
                 .{ .name = "Content-Type", .value = "text/html; charset=utf-8" },
+                .{ .name = "Access-Control-Allow-Origin", .value = origin(req) orelse "*" },
             },
         });
     }
@@ -1201,6 +1221,16 @@ fn testHTTPHandler(req: *std.http.Server.Request) !void {
     }
 
     if (std.mem.eql(u8, path, "/echo_headers")) {
+        if (req.head.method == .OPTIONS) {
+            return req.respond("", .{
+                .extra_headers = &.{
+                    .{ .name = "Access-Control-Allow-Origin", .value = origin(req) orelse "*" },
+                    .{ .name = "Access-Control-Allow-Methods", .value = "GET" },
+                    .{ .name = "Access-Control-Allow-Headers", .value = "x-hop" },
+                },
+            });
+        }
+
         // Echo every request header back as "name: value" lines, so tests
         // can assert on the headers a request actually sent.
         var buf: [8192]u8 = undefined;
@@ -1213,6 +1243,7 @@ fn testHTTPHandler(req: *std.http.Server.Request) !void {
         return req.respond(buf[0..pos], .{
             .extra_headers = &.{
                 .{ .name = "Content-Type", .value = "text/plain; charset=utf-8" },
+                .{ .name = "Access-Control-Allow-Origin", .value = origin(req) orelse "*" },
             },
         });
     }