Emit "log" events when logging, and some cleanup

lib/utils/log.js

@@ -18,10 +18,11 @@ silent quiets everything
 
 module.exports = log
 var stdio = process.binding("stdio")
-  , doColor
 function colorize (msg, color) {
   if (!msg) return ""
-  if (doColor === undefined) {
+  var logStream = getLogStream()
+    , doColor = false
+  if (logStream) {
     try {
       doColor = stdio.isatty(logStream.fd)
     } catch (ex) {
@@ -95,7 +96,6 @@ Object.defineProperty(log, "level",
       npm.config.set("showlevel", l)
     }
   })
-var logStream
 function log (msg, pref, level, cb) {
   if (typeof level === "function") cb = level, level = null
   var show = log.level
@@ -128,23 +128,37 @@ function log (msg, pref, level, cb) {
     return
   }
   log.level = show
+  npm.emit("log", { level : level, msg : msg, pref : pref, cb : cb })
+}
 
+var logStream
+function getLogStream () {
   var logFD = npm.config.get("logfd")
     , ls
   // effectively sending errors to /dev/null
-  if (!logFD && logFD !== 0) cb && cb() || true
+  if (!logFD && logFD !== 0) return
   if (typeof logFD === "string") logFD = +logFD
   if (logFD && typeof logFD === "object") {
     ls = logFD
     logFD = ls.fd
   }
   if (!logStream || logStream.fd !== logFD) {
     if (!ls) try { ls = new net.Stream(logFD) } catch (ex) {}
-    if (!ls || !ls.writable) return cb && cb() || true
+    if (!ls || !ls.writable) return
     logStream = ls
   }
+  return logStream
+}
 
-  if (!isFinite(level) || level < show) return cb && cb()
+npm.on("log", function (logData) {
+  var level = logData.level
+    , msg = logData.msg
+    , pref = logData.pref
+    , cb = logData.cb || function () {}
+    , logStream = getLogStream()
+    , show = log.level
+    , spaces = "    "
+  if (!isFinite(level) || level < show) return cb()
   // console.error("level, showlevel, show", level, show, (level >= show))
   pref = colorize("npm", COLOR.npm)
        + (COLOR[level] ? " "+colorize(
@@ -163,8 +177,8 @@ function log (msg, pref, level, cb) {
     cb()
   })
   return flushed
-}
-var spaces = "    "
+})
+
 log.er = function (cb, msg) {
   if (!msg) throw new Error(
     "Why bother logging it if you're not going to print a message?")