Add JSValue.typeOf

Signed-off-by: Francis Bouvier <francis@lightpanda.io>

Author: francisbouvier

src/api.zig

@@ -41,6 +41,17 @@ pub const test_utils = @import("tests/test_utils.zig");
 // JS types
 // --------
 
+pub const JSTypes = enum {
+    object,
+    function,
+    string,
+    number,
+    boolean,
+    bigint,
+    null,
+    undefined,
+};
+
 const types = @import("types.zig");
 pub const i64Num = types.i64Num;
 pub const u64Num = types.u64Num;

src/engines/v8/v8.zig

@@ -426,6 +426,18 @@ pub const JSValue = struct {
     pub fn toString(self: JSValue, alloc: std.mem.Allocator, env: Env) anyerror![]const u8 {
         return valueToUtf8(alloc, self.value, env.isolate, env.js_ctx.?);
     }
+
+    pub fn typeOf(self: JSValue, env: Env) anyerror!public.JSTypes {
+        var buf: [20]u8 = undefined;
+        const str = try self.value.typeOf(env.isolate);
+        const len = str.lenUtf8(env.isolate);
+        const s = buf[0..len];
+        _ = str.writeUtf8(env.isolate, s);
+        return std.meta.stringToEnum(public.JSTypes, s) orelse {
+            std.log.err("JSValueTypeNotHandled: {s}", .{s});
+            return error.JSValueTypeNotHandled;
+        };
+    }
 };
 
 pub const TryCatch = struct {

src/interfaces.zig

@@ -116,6 +116,9 @@ pub fn JSValue(comptime T: type, env: type) void {
 
     // toString()
     assertDecl(T, "toString", fn (self: T, alloc: std.mem.Allocator, env: env) anyerror![]const u8);
+
+    // typeOf()
+    assertDecl(T, "typeOf", fn (self: T, env: env) anyerror!public.JSTypes);
 }
 
 pub fn JSObjectID(comptime T: type) void {