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, 18 insertions, 4 deletions

diff --git a/lib/cli.js b/lib/cli.js
index 910b674ea..837d0876c 100644
--- a/lib/cli.js
+++ b/lib/cli.js
@@ -40,11 +40,14 @@ module.exports = (process) => {
   npm.load(async er => {
     if (er)
       return errorHandler(er)
+
+    // npm --version=cli
     if (npm.config.get('version', 'cli')) {
-      console.log(npm.version)
+      npm.output(npm.version)
       return errorHandler.exit(0)
     }
 
+    // npm --versions=cli
     if (npm.config.get('versions', 'cli')) {
       npm.argv = ['version']
       npm.config.set('usage', false, 'cli')
@@ -57,9 +60,20 @@ module.exports = (process) => {
     if (impl)
       impl(npm.argv, errorHandler)
     else {
-      npm.config.set('usage', false)
-      npm.argv.unshift(cmd)
-      npm.commands.help(npm.argv, errorHandler)
+      try {
+        // I don't know why this is needed but we get a cb() not called if we
+        // omit it
+        npm.log.level = 'silent'
+        if (cmd) {
+          const didYouMean = require('./utils/did-you-mean.js')
+          const suggestions = await didYouMean(npm, cmd)
+          npm.output(suggestions)
+        } else
+          npm.output(npm.usage)
+        process.exitCode = 1
+      } catch (err) {
+        errorHandler(err)
+      }
     }
   })
 }