From 99229513ba5ec6f668951bbbfe6e5e0217087235 Mon Sep 17 00:00:00 2001
From: Pierre Tachoire <pierre@lightpanda.io>
Date: Sat, 10 May 2025 17:00:57 +0200
Subject: [PATCH] implement TextEncoder

---
 src/browser/encoding/text_encoder.zig | 64 +++++++++++++++++++++++++++
 src/browser/env.zig                   |  1 +
 2 files changed, 65 insertions(+)
 create mode 100644 src/browser/encoding/text_encoder.zig

diff --git a/src/browser/encoding/text_encoder.zig b/src/browser/encoding/text_encoder.zig
new file mode 100644
index 00000000..5bf9b7d7
--- /dev/null
+++ b/src/browser/encoding/text_encoder.zig
@@ -0,0 +1,64 @@
+// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// 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 Env = @import("../env.zig").Env;
+
+pub const Interfaces = .{
+    TextEncoder,
+};
+
+// https://encoding.spec.whatwg.org/#interface-textencoder
+pub const TextEncoder = struct {
+    pub fn constructor() !TextEncoder {
+        return .{};
+    }
+
+    pub fn get_encoding(_: *const TextEncoder) []const u8 {
+        return "utf-8";
+    }
+
+    pub fn _encode(_: *const TextEncoder, v: []const u8) !Env.TypedArray(u8) {
+        // Ensure the input is a valid utf-8
+        // It seems chrome accepts invalid utf-8 sequence.
+        //
+        if (!std.unicode.utf8ValidateSlice(v)) {
+            return error.InvalidUtf8;
+        }
+
+        return .{ .values = v };
+    }
+};
+
+const testing = @import("../../testing.zig");
+test "Browser.Encoding.TextEncoder" {
+    var runner = try testing.jsRunner(testing.tracking_allocator, .{});
+    defer runner.deinit();
+
+    try runner.testCases(&.{
+        .{ "var encoder = new TextEncoder();", "undefined" },
+        .{ "encoder.encoding;", "utf-8" },
+        .{ "encoder.encode('€');", "226,130,172" },
+
+        // Invalid utf-8 sequence.
+        // Result with chrome:
+        // .{ "encoder.encode(new Uint8Array([0xE2,0x28,0xA1]))", "50,50,54,44,52,48,44,49,54,49" },
+        .{ "try {encoder.encode(new Uint8Array([0xE2,0x28,0xA1])) } catch (e) { e };", "Error: InvalidUtf8" },
+    }, .{});
+}
diff --git a/src/browser/env.zig b/src/browser/env.zig
index 3f04ff09..8d3e253b 100644
--- a/src/browser/env.zig
+++ b/src/browser/env.zig
@@ -28,6 +28,7 @@ const WebApis = struct {
         @import("crypto/crypto.zig").Crypto,
         @import("console/console.zig").Console,
         @import("dom/dom.zig").Interfaces,
+        @import("encoding/text_encoder.zig").Interfaces,
         @import("events/event.zig").Interfaces,
         @import("html/html.zig").Interfaces,
         @import("iterator/iterator.zig").Interfaces,