From b74cfa838e221d226b905d58542d6ddabac843c5 Mon Sep 17 00:00:00 2001
From: iddev5 <ayushbardhan5@gmail.com>
Date: Fri, 8 Jul 2022 23:26:09 +0530
Subject: [PATCH] js-runtime: Implement ``fn format()`` for js.Value for easier
 debugging and logging

---
 js-runtime/src/main.zig | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/js-runtime/src/main.zig b/js-runtime/src/main.zig
index 35846300..23eb323a 100644
--- a/js-runtime/src/main.zig
+++ b/js-runtime/src/main.zig
@@ -80,6 +80,21 @@ pub const Value = extern struct {
     pub fn instanceOf(val: *const Value, other: Value) bool {
         return js.zigValueInstanceOf(val, &other);
     }
+
+    pub fn format(val: *const Value, comptime _: []const u8, _: std.fmt.FormatOptions, writer: anytype) !void {
+        switch (val.tag) {
+            .object => try writer.print("Object@{}({})", .{ val.val.ref, val.view(.object).attributeCount() }),
+            .num => if (val.val.num > 10000)
+                try writer.print("{e}", .{val.val.num})
+            else
+                try writer.print("{d}", .{val.val.num}),
+            .bool => try writer.writeAll(if (val.view(.bool)) "true" else "false"),
+            .str => try writer.print("String@{}({})", .{ val.val.ref, val.view(.str).getLength() }),
+            .func => try writer.print("Function@{}({})", .{ val.val.ref, val.view(.func).paramCount() }),
+            .nulled => try writer.writeAll("null"),
+            .undef => try writer.writeAll("undefined"),
+        }
+    }
 };
 
 pub const Object = struct {