feat: streaming debug logfile

This decouples the log file writing from the terminal logging. We now
open an append only file at the start of the process and stream logs to
it. We still only display the log file message in timing mode or if
there is an error, but the file is still written regardless.

All logging now goes through `proc-log` and this is the first step to
removing `npmlog`. For now `npmlog` is still used for the terminal
logging but with a shim in front of it to make it easier to test and
use in conjunction with `proc-log`. Ref: npm/statusboard#366

This also refactors many of the tests to always use an explicit
`t.testdir` for their cache since the file is opened on each `new Npm()`.
Tests are also refactored to use more of `MockNpm` with behavior to
add config items and load `npm` if necessary. A new fixture `mockGlobals`
was also added to make much of this more ergonomic. Ref: npm/statusboard#410

Closes npm/statusboard#411
Closes npm/statusboard#367

PR-URL: https://github.com/npm/cli/pull/4062
Credit: @lukekarrys
Close: #4062
Reviewed-by: @wraithgar

1 files changed, 17 insertions, 16 deletions

diff --git a/lib/cli.js b/lib/cli.js
index 9dcd9d04d..3d0c32d4b 100644
--- a/lib/cli.js
+++ b/lib/cli.js
@@ -4,20 +4,23 @@ module.exports = async process => {
   // leak any private CLI configs to other programs
   process.title = 'npm'
 
-  const { checkForBrokenNode, checkForUnsupportedNode } = require('../lib/utils/unsupported.js')
-
+  // We used to differentiate between known broken and unsupported
+  // versions of node and attempt to only log unsupported but still run.
+  // After we dropped node 10 support, we can use new features
+  // (like static, private, etc) which will only give vague syntax errors,
+  // so now both broken and unsupported use console, but only broken
+  // will process.exit. It is important to now perform *both* of these
+  // checks as early as possible so the user gets the error message.
+  const { checkForBrokenNode, checkForUnsupportedNode } = require('./utils/unsupported.js')
   checkForBrokenNode()
-
-  const log = require('npmlog')
-  // pause it here so it can unpause when we've loaded the configs
-  // and know what loglevel we should be printing.
-  log.pause()
-
   checkForUnsupportedNode()
 
-  const Npm = require('../lib/npm.js')
+  const exitHandler = require('./utils/exit-handler.js')
+  process.on('uncaughtException', exitHandler)
+  process.on('unhandledRejection', exitHandler)
+
+  const Npm = require('./npm.js')
   const npm = new Npm()
-  const exitHandler = require('../lib/utils/exit-handler.js')
   exitHandler.setNpm(npm)
 
   // if npm is called as "npmg" or "npm_g", then
@@ -26,16 +29,14 @@ module.exports = async process => {
     process.argv.splice(1, 1, 'npm', '-g')
   }
 
-  const replaceInfo = require('../lib/utils/replace-info.js')
+  const log = require('./utils/log-shim.js')
+  const replaceInfo = require('./utils/replace-info.js')
   log.verbose('cli', replaceInfo(process.argv))
 
   log.info('using', 'npm@%s', npm.version)
   log.info('using', 'node@%s', process.version)
 
-  process.on('uncaughtException', exitHandler)
-  process.on('unhandledRejection', exitHandler)
-
-  const updateNotifier = require('../lib/utils/update-notifier.js')
+  const updateNotifier = require('./utils/update-notifier.js')
 
   let cmd
   // now actually fire up npm and run the command.
@@ -63,7 +64,7 @@ module.exports = async process => {
     }
 
     await npm.exec(cmd, npm.argv)
-    exitHandler()
+    return exitHandler()
   } catch (err) {
     if (err.code === 'EUNKNOWNCOMMAND') {
       const didYouMean = require('./utils/did-you-mean.js')