hook up logging to wasm, example uses new zig-js package

src/font/face/web_canvas.zig

@@ -49,6 +49,8 @@ pub const Face = struct {
         const canvas = try doc.call(js.Object, "createElement", .{js.string("canvas")});
         errdefer canvas.deinit();
 
+        log.debug("face initialized: {s}", .{raw});
+
         return Face{
             .alloc = alloc,
             .font_str = font_str,

src/main_wasm.zig

@@ -1,6 +1,17 @@
 // This is the main file for the WASM module. The WASM module has to
 // export a C ABI compatible API.
+const std = @import("std");
+const builtin = @import("builtin");
 
 pub usingnamespace @import("os/wasm.zig");
 pub usingnamespace @import("os/wasm/log.zig");
 pub usingnamespace @import("font/main.zig");
+
+// Set our log level. We try to get as much logging as possible but in
+// ReleaseSmall mode where we're optimizing for space, we elevate the
+// log level.
+pub const log_level: std.log.Level = switch (builtin.mode) {
+    .Debug => .debug,
+    .ReleaseSmall => .warn,
+    else => .info,
+};

src/os/wasm.zig

@@ -37,6 +37,18 @@ pub export fn malloc(len: usize) ?[*]u8 {
     return alloc_(len) catch return null;
 }
 
+fn alloc_(len: usize) ![*]u8 {
+    // Create the allocation
+    const slice = try alloc.alloc(u8, len);
+    errdefer alloc.free(slice);
+
+    // Store the size so we can deallocate later
+    try allocs.putNoClobber(alloc, slice.ptr, slice.len);
+    errdefer _ = allocs.remove(slice.ptr);
+
+    return slice.ptr;
+}
+
 /// Free an allocation from malloc.
 pub export fn free(ptr: ?[*]u8) void {
     if (ptr) |v| {
@@ -79,18 +91,6 @@ pub fn toModuleOwned(ptr: anytype) void {
     _ = allocs.remove(casted);
 }
 
-fn alloc_(len: usize) ![*]u8 {
-    // Create the allocation
-    const slice = try alloc.alloc(u8, len);
-    errdefer alloc.free(slice);
-
-    // Store the size so we can deallocate later
-    try allocs.putNoClobber(alloc, slice.ptr, slice.len);
-    errdefer _ = allocs.remove(slice.ptr);
-
-    return slice.ptr;
-}
-
 test "basics" {
     const testing = std.testing;
     var buf = malloc(32).?;