feature: sk-react-toolkit holds the server helpers, web components and Vite font plugin shared by manage-ui and sql-query-webui.

server/log.ts

@@ -0,0 +1,42 @@
+/** The log of a server: events to stdout, warnings and errors in colour to stderr, and requests when they are on. */
+export type Log = {
+  event: (text: string) => void
+  warn: (text: string) => void
+  error: (text: string) => void
+  request: (text: string) => void
+}
+
+/** A log that writes nothing, for tests. */
+export const QUIET: Log = { event() {}, warn() {}, error() {}, request() {} }
+
+/**
+ * The log of a server. With timestamps each line starts with the local time with milliseconds; requests logs each
+ * request to stderr, otherwise request writes nothing.
+ */
+export function createLog(options: { timestamps: boolean; requests: boolean }): Log {
+  const line = (text: string) => {
+    if (!options.timestamps) {
+      return text
+    }
+    const now = new Date()
+    const pad = (value: number, size = 2) => String(value).padStart(size, '0')
+    return `${pad(now.getHours())}:${pad(now.getMinutes())}:${pad(now.getSeconds())}.${pad(now.getMilliseconds(), 3)} ${text}`
+  }
+  return {
+    event: (text) => console.log(line(text)),
+    warn: (text) => console.error(`\x1b[33m${line(`warning: ${text}`)}\x1b[0m`),
+    error: (text) => console.error(`\x1b[31m${line(`error: ${text}`)}\x1b[0m`),
+    request: options.requests ? (text) => console.error(line(text)) : () => {},
+  }
+}
+
+/** Whether --timestamps auto|on|off asks for timestamps: auto only when stdout is a terminal. */
+export function timestampsOn(choice: string) {
+  return choice === 'on' || (choice === 'auto' && process.stdout.isTTY === true)
+}
+
+/** Prints the message in red to stderr as an error and ends the process with status 2. */
+export function fail(message: string): never {
+  console.error(`\x1b[31merror: ${message}\x1b[0m`)
+  process.exit(2)
+}