Add `util.inspect.custom` support to `util.inspect/Bun.inspect/console.log` (#4194)

* start work on util.inspect.custom

* asdf

* finish util inspect custom inspect

* inspect

* fix tests

* revert

* tidy

* revert

* oops

* test

* fix issues

1 files changed, 17 insertions, 0 deletions

diff --git a/src/js/builtins/UtilInspect.ts b/src/js/builtins/UtilInspect.ts
new file mode 100644
index 000000000..586f03b57
--- /dev/null
+++ b/src/js/builtins/UtilInspect.ts
@@ -0,0 +1,17 @@
+type Inspect = typeof import("util").inspect;
+
+// This is passed to [util.inspect.custom](..., { stylize }) to help users colorize parts.
+export function getStylizeWithColor(inspect: Inspect) {
+  return function stylizeWithColor(str: string, styleType: string) {
+    const style = inspect.styles[styleType];
+    if (style !== undefined) {
+      const color = inspect.colors[style];
+      if (color !== undefined) return `\u001b[${color[0]}m${str}\u001b[${color[1]}m`;
+    }
+    return str;
+  };
+}
+
+export function stylizeWithNoColor(str: string) {
+  return str;
+}