From 7e3de57bb48486cd6147d5a40335862a6f423baf Mon Sep 17 00:00:00 2001
From: Dan Connolly <connolly@agoric.com>
Date: Tue, 20 Jun 2023 15:21:14 -0500
Subject: [PATCH] chore(inter-cli): makeTUI - Textual User Interface

---
 packages/inter-cli/src/lib/tui.js | 39 +++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 packages/inter-cli/src/lib/tui.js

diff --git a/packages/inter-cli/src/lib/tui.js b/packages/inter-cli/src/lib/tui.js
new file mode 100644
index 00000000000..947fc827ac7
--- /dev/null
+++ b/packages/inter-cli/src/lib/tui.js
@@ -0,0 +1,39 @@
+// @ts-check
+// @jessie-check
+
+/**
+ * JSON.stringify replacer to handle bigint
+ *
+ * @param {unknown} k
+ * @param {unknown} v
+ */
+export const bigintReplacer = (k, v) => (typeof v === 'bigint' ? `${v}` : v);
+
+/**
+ * TUI - a Textual User Interface
+ *
+ * @param {{
+ *   stdout: Pick<import('stream').Writable, 'write'>,
+ *   logger: Pick<typeof console, 'warn'>,
+ * }} io
+ * @typedef {ReturnType<makeTUI>} TUI
+ */
+export const makeTUI = ({ stdout, logger }) => {
+  /**
+   * write info as JSON
+   *
+   * @param {unknown} info JSON.strigify()-able data (bigint replaced with string)
+   * @param {boolean} [indent] normally false, keeping the JSON on one line
+   */
+  const show = (info, indent = false) => {
+    stdout.write(
+      `${JSON.stringify(info, bigintReplacer, indent ? 2 : undefined)}\n`,
+    );
+  };
+
+  return Object.freeze({
+    show,
+    /** @type {typeof console.warn} */
+    warn: (...args) => logger.warn(...args),
+  });
+};