polyfill: first draft to polyfill fetch api

src/polyfill/polyfill.zig

@@ -0,0 +1,38 @@
+const std = @import("std");
+const builtin = @import("builtin");
+
+const jsruntime = @import("jsruntime");
+const Env = jsruntime.Env;
+
+const fetch = @import("fetch.zig").fetch_polyfill;
+
+const log = std.log.scoped(.polyfill);
+
+const modules = [_]struct {
+    name: []const u8,
+    source: []const u8,
+}{
+    .{ .name = "polyfill-fetch", .source = @import("fetch.zig").source },
+};
+
+pub fn load(alloc: std.mem.Allocator, env: Env) !void {
+    var try_catch: jsruntime.TryCatch = undefined;
+    try_catch.init(env);
+    defer try_catch.deinit();
+
+    for (modules) |m| {
+        const res = env.exec(m.source, m.name) catch {
+            if (try try_catch.err(alloc, env)) |msg| {
+                defer alloc.free(msg);
+                log.err("load {s}: {s}", .{ m.name, msg });
+            }
+            return;
+        };
+
+        if (builtin.mode == .Debug) {
+            const msg = try res.toString(alloc, env);
+            defer alloc.free(msg);
+            log.debug("load {s}: {s}", .{ m.name, msg });
+        }
+    }
+}