initial fetch in zig

Author: mookums

src/browser/env.zig

@@ -36,8 +36,9 @@ const WebApis = struct {
         @import("xhr/form_data.zig").Interfaces,
         @import("xhr/File.zig"),
         @import("xmlserializer/xmlserializer.zig").Interfaces,
-        @import("fetch/Request.zig"),
         @import("fetch/Headers.zig"),
+        @import("fetch/Request.zig"),
+        @import("fetch/Response.zig"),
     });
 };
 

src/browser/fetch/Request.zig

@@ -20,18 +20,36 @@ const std = @import("std");
 const URL = @import("../../url.zig").URL;
 const Page = @import("../page.zig").Page;
 
-// https://developer.mozilla.org/en-US/docs/Web/API/Request/Request
-const Request = @This();
+const Response = @import("./Response.zig");
 
-url: []const u8,
+const Http = @import("../../http/Http.zig");
+const HttpClient = @import("../../http/Client.zig");
+const Mime = @import("../mime.zig").Mime;
 
-const RequestInput = union(enum) {
+const v8 = @import("v8");
+const Env = @import("../env.zig").Env;
+
+pub const RequestInput = union(enum) {
     string: []const u8,
     request: Request,
 };
 
-pub fn constructor(input: RequestInput, page: *Page) !Request {
+// https://developer.mozilla.org/en-US/docs/Web/API/RequestInit
+pub const RequestInit = struct {
+    method: []const u8 = "GET",
+    body: []const u8 = "",
+};
+
+// https://developer.mozilla.org/en-US/docs/Web/API/Request/Request
+const Request = @This();
+
+method: Http.Method,
+url: []const u8,
+body: []const u8,
+
+pub fn constructor(input: RequestInput, _options: ?RequestInit, page: *Page) !Request {
     const arena = page.arena;
+    const options: RequestInit = _options orelse .{};
 
     const url = blk: switch (input) {
         .string => |str| {
@@ -42,13 +60,146 @@ pub fn constructor(input: RequestInput, page: *Page) !Request {
         },
     };
 
+    const method: Http.Method = blk: for (std.enums.values(Http.Method)) |method| {
+        if (std.ascii.eqlIgnoreCase(options.method, @tagName(method))) {
+            break :blk method;
+        }
+    } else {
+        return error.InvalidMethod;
+    };
+
+    const body = try arena.dupe(u8, options.body);
+
     return .{
+        .method = method,
         .url = url,
+        .body = body,
     };
 }
 
-pub fn get_url(self: *const Request, page: *Page) ![]const u8 {
-    return try page.arena.dupe(u8, self.url);
+pub fn get_url(self: *const Request) []const u8 {
+    return self.url;
+}
+
+pub fn get_method(self: *const Request) []const u8 {
+    return @tagName(self.method);
+}
+
+pub fn get_body(self: *const Request) []const u8 {
+    return self.body;
+}
+
+const FetchContext = struct {
+    arena: std.mem.Allocator,
+    js_ctx: *Env.JsContext,
+    promise_resolver: v8.Persistent(v8.PromiseResolver),
+
+    body: std.ArrayListUnmanaged(u8) = .empty,
+    headers: std.ArrayListUnmanaged([]const u8) = .empty,
+    status: u16 = 0,
+    mime: ?Mime = null,
+    transfer: ?*HttpClient.Transfer = null,
+
+    /// This effectively takes ownership of the FetchContext.
+    ///
+    /// We just return the underlying slices used for `headers`
+    /// and for `body` here to avoid an allocation.
+    pub fn toResponse(self: FetchContext) !Response {
+        return Response{
+            .status = self.status,
+            .headers = self.headers.items,
+            .mime = self.mime,
+            .body = self.body.items,
+        };
+    }
+};
+
+// https://developer.mozilla.org/en-US/docs/Web/API/Window/fetch
+pub fn fetch(input: RequestInput, options: ?RequestInit, page: *Page) !Env.Promise {
+    const arena = page.arena;
+
+    const req = try Request.constructor(input, options, page);
+    const resolver = Env.PromiseResolver{
+        .js_context = page.main_context,
+        .resolver = v8.PromiseResolver.init(page.main_context.v8_context),
+    };
+
+    const client = page.http_client;
+    const headers = try HttpClient.Headers.init();
+
+    const fetch_ctx = try arena.create(FetchContext);
+    fetch_ctx.* = .{
+        .arena = page.arena,
+        .js_ctx = page.main_context,
+        .promise_resolver = v8.Persistent(v8.PromiseResolver).init(page.main_context.isolate, resolver.resolver),
+    };
+
+    try client.request(.{
+        .method = req.method,
+        .url = try arena.dupeZ(u8, req.url),
+        .headers = headers,
+        .body = req.body,
+        .cookie_jar = page.cookie_jar,
+        .ctx = @ptrCast(fetch_ctx),
+
+        .start_callback = struct {
+            fn startCallback(transfer: *HttpClient.Transfer) !void {
+                const self: *FetchContext = @alignCast(@ptrCast(transfer.ctx));
+                self.transfer = transfer;
+            }
+        }.startCallback,
+        .header_callback = struct {
+            fn headerCallback(transfer: *HttpClient.Transfer, header: []const u8) !void {
+                const self: *FetchContext = @alignCast(@ptrCast(transfer.ctx));
+                try self.headers.append(self.arena, try self.arena.dupe(u8, header));
+            }
+        }.headerCallback,
+        .header_done_callback = struct {
+            fn headerDoneCallback(transfer: *HttpClient.Transfer) !void {
+                const self: *FetchContext = @alignCast(@ptrCast(transfer.ctx));
+                const header = &transfer.response_header.?;
+
+                if (header.contentType()) |ct| {
+                    self.mime = Mime.parse(ct) catch {
+                        return error.Todo;
+                    };
+                }
+
+                self.status = header.status;
+            }
+        }.headerDoneCallback,
+        .data_callback = struct {
+            fn dataCallback(transfer: *HttpClient.Transfer, data: []const u8) !void {
+                const self: *FetchContext = @alignCast(@ptrCast(transfer.ctx));
+                try self.body.appendSlice(self.arena, data);
+            }
+        }.dataCallback,
+        .done_callback = struct {
+            fn doneCallback(ctx: *anyopaque) !void {
+                const self: *FetchContext = @alignCast(@ptrCast(ctx));
+                const response = try self.toResponse();
+                const promise_resolver: Env.PromiseResolver = .{
+                    .js_context = self.js_ctx,
+                    .resolver = self.promise_resolver.castToPromiseResolver(),
+                };
+
+                try promise_resolver.resolve(response);
+            }
+        }.doneCallback,
+        .error_callback = struct {
+            fn errorCallback(ctx: *anyopaque, err: anyerror) void {
+                const self: *FetchContext = @alignCast(@ptrCast(ctx));
+                const promise_resolver: Env.PromiseResolver = .{
+                    .js_context = self.js_ctx,
+                    .resolver = self.promise_resolver.castToPromiseResolver(),
+                };
+
+                promise_resolver.reject(@errorName(err)) catch unreachable;
+            }
+        }.errorCallback,
+    });
+
+    return resolver.promise();
 }
 
 const testing = @import("../../testing.zig");
@@ -59,10 +210,44 @@ test "fetch: request" {
     try runner.testCases(&.{
         .{ "let request = new Request('flower.png')", "undefined" },
         .{ "request.url", "https://lightpanda.io/flower.png" },
+        .{ "request.method", "GET" },
     }, .{});
 
     try runner.testCases(&.{
-        .{ "let request2 = new Request('https://google.com')", "undefined" },
+        .{ "let request2 = new Request('https://google.com', { method: 'POST', body: 'Hello, World' })", "undefined" },
         .{ "request2.url", "https://google.com" },
+        .{ "request2.method", "POST" },
+        .{ "request2.body", "Hello, World" },
+    }, .{});
+}
+
+test "fetch: Browser.fetch" {
+    var runner = try testing.jsRunner(testing.tracking_allocator, .{});
+    defer runner.deinit();
+
+    try runner.testCases(&.{
+        .{
+            \\  var ok = false;
+            \\  const request = new Request("http://127.0.0.1:9582/loader");
+            \\  fetch(request).then((response) => { ok = response.ok; });
+            \\  false;
+            ,
+            "false",
+        },
+        // all events have been resolved.
+        .{ "ok", "true" },
+    }, .{});
+
+    try runner.testCases(&.{
+        .{
+            \\  var ok2 = false;
+            \\  const request2 = new Request("http://127.0.0.1:9582/loader");
+            \\  (async function () { resp = await fetch(request2); ok2 = resp.ok; }());
+            \\  false;
+            ,
+            "false",
+        },
+        // all events have been resolved.
+        .{ "ok2", "true" },
     }, .{});
 }

src/browser/fetch/Response.zig

@@ -0,0 +1,64 @@
+// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <[email protected]>
+// Pierre Tachoire <[email protected]>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const std = @import("std");
+const URL = @import("../../url.zig").URL;
+const Page = @import("../page.zig").Page;
+
+const Http = @import("../../http/Http.zig");
+const HttpClient = @import("../../http/Client.zig");
+const Mime = @import("../mime.zig").Mime;
+
+// https://developer.mozilla.org/en-US/docs/Web/API/Response
+const Response = @This();
+
+status: u16 = 0,
+headers: []const []const u8,
+mime: ?Mime = null,
+body: []const u8,
+
+const ResponseInput = union(enum) {
+    string: []const u8,
+};
+
+pub fn constructor(input: ResponseInput, page: *Page) !Response {
+    const arena = page.arena;
+
+    const body = blk: switch (input) {
+        .string => |str| {
+            break :blk try arena.dupe(u8, str);
+        },
+    };
+
+    return .{
+        .body = body,
+        .headers = &[_][]const u8{},
+    };
+}
+
+pub fn get_ok(self: *const Response) bool {
+    return self.status >= 200 and self.status <= 299;
+}
+
+const testing = @import("../../testing.zig");
+test "fetch: response" {
+    var runner = try testing.jsRunner(testing.tracking_allocator, .{ .url = "https://lightpanda.io" });
+    defer runner.deinit();
+
+    try runner.testCases(&.{}, .{});
+}

src/browser/html/window.zig

@@ -39,6 +39,9 @@ const Css = @import("../css/css.zig").Css;
 const Function = Env.Function;
 const JsObject = Env.JsObject;
 
+const v8 = @import("v8");
+const Request = @import("../fetch/Request.zig");
+
 const storage = @import("../storage/storage.zig");
 
 // https://dom.spec.whatwg.org/#interface-window-extensions
@@ -95,6 +98,10 @@ pub const Window = struct {
         self.storage_shelf = shelf;
     }
 
+    pub fn _fetch(_: *Window, input: Request.RequestInput, options: ?Request.RequestInit, page: *Page) !Env.Promise {
+        return Request.fetch(input, options, page);
+    }
+
     pub fn get_window(self: *Window) *Window {
         return self;
     }

src/http/Http.zig

@@ -339,13 +339,13 @@ pub const Opts = struct {
     proxy_bearer_token: ?[:0]const u8 = null,
 };
 
-pub const Method = enum {
-    GET,
-    PUT,
-    POST,
-    DELETE,
-    HEAD,
-    OPTIONS,
+pub const Method = enum(u8) {
+    GET = 0,
+    PUT = 1,
+    POST = 2,
+    DELETE = 3,
+    HEAD = 4,
+    OPTIONS = 5,
 };
 
 // TODO: on BSD / Linux, we could just read the PEM file directly.

src/runtime/js.zig

@@ -2178,6 +2178,17 @@ pub fn Env(comptime State: type, comptime WebApis: type) type {
                     return error.FailedToResolvePromise;
                 }
             }
+
+            pub fn reject(self: PromiseResolver, value: anytype) !void {
+                const js_context = self.js_context;
+                const js_value = try js_context.zigValueToJs(value);
+
+                // resolver.reject will return null if the promise isn't pending
+                const ok = self.resolver.reject(js_context.v8_context, js_value) orelse return;
+                if (!ok) {
+                    return error.FailedToRejectPromise;
+                }
+            }
         };
 
         pub const Promise = struct {