feat(help): refactor npm help/help-search

Lots of dead code removed thanks to streamlining of logic.
`npm help` `npm <command>` and `npm help-search` are all now separated
concerns, handling their own use cases. `help` calls `help-search` as a
last resort, but `npm <command>` no longer tries to wind its way through
to `help-search` just to get the basic npm usage displayed.

The `did you mean` output has been expanded. It now always suggests top
level commands, scripts, and bins, and suggests them in the way they
should be called.

PR-URL: https://github.com/npm/cli/pull/2859
Credit: @wraithgar
Close: #2859
Reviewed-by: @ruyadorno

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/npm.js b/lib/npm.js
index d80067a11..78b6ba034 100644
--- a/lib/npm.js
+++ b/lib/npm.js
@@ -38,6 +38,7 @@ const proxyCmds = new Proxy({}, {
 
 const { definitions, flatten, shorthands } = require('./utils/config/index.js')
 const { shellouts } = require('./utils/cmd-list.js')
+const usage = require('./utils/npm-usage.js')
 
 let warnedNonDashArg = false
 const _runCmd = Symbol('_runCmd')
@@ -100,7 +101,7 @@ const npm = module.exports = new class extends EventEmitter {
     }
 
     if (this.config.get('usage')) {
-      console.log(impl.usage)
+      this.output(impl.usage)
       cb()
     } else {
       impl.exec(args, er => {
@@ -274,6 +275,10 @@ const npm = module.exports = new class extends EventEmitter {
     this[k] = r
   }
 
+  get usage () {
+    return usage(this)
+  }
+
   // XXX add logging to see if we actually use this
   get tmp () {
     if (!this[_tmpFolder]) {