feat(cli): enable timestamped run output by default

src/cli/run/timestamp-output.ts

@@ -0,0 +1,70 @@
+function formatTimestamp(date: Date): string {
+  const hh = String(date.getHours()).padStart(2, "0")
+  const mm = String(date.getMinutes()).padStart(2, "0")
+  const ss = String(date.getSeconds()).padStart(2, "0")
+  return `${hh}:${mm}:${ss}`
+}
+
+export function createTimestampTransformer(now: () => Date = () => new Date()): (chunk: string) => string {
+  let atLineStart = true
+
+  return (chunk: string): string => {
+    if (!chunk) return ""
+
+    let output = ""
+    for (let i = 0; i < chunk.length; i++) {
+      const ch = chunk[i]
+      if (atLineStart) {
+        output += `[${formatTimestamp(now())}] `
+        atLineStart = false
+      }
+
+      output += ch
+
+      if (ch === "\n") {
+        atLineStart = true
+      }
+    }
+
+    return output
+  }
+}
+
+type WriteFn = NodeJS.WriteStream["write"]
+
+export function createTimestampedStdoutController(stdout: NodeJS.WriteStream = process.stdout): {
+  enable: () => void
+  restore: () => void
+} {
+  const originalWrite = stdout.write.bind(stdout)
+  const transform = createTimestampTransformer()
+
+  function enable(): void {
+    const write: WriteFn = (
+      chunk: Uint8Array | string,
+      encodingOrCallback?: BufferEncoding | ((error?: Error | null) => void),
+      callback?: (error?: Error | null) => void,
+    ): boolean => {
+      const text = typeof chunk === "string"
+        ? chunk
+        : Buffer.from(chunk).toString(typeof encodingOrCallback === "string" ? encodingOrCallback : undefined)
+      const stamped = transform(text)
+
+      if (typeof encodingOrCallback === "function") {
+        return originalWrite(stamped, encodingOrCallback)
+      }
+      if (encodingOrCallback !== undefined) {
+        return originalWrite(stamped, encodingOrCallback, callback)
+      }
+      return originalWrite(stamped)
+    }
+
+    stdout.write = write
+  }
+
+  function restore(): void {
+    stdout.write = originalWrite
+  }
+
+  return { enable, restore }
+}