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, 30 insertions, 22 deletions

diff --git a/test/lib/load-all-commands.js b/test/lib/load-all-commands.js
index e31a2b993..2a2d41818 100644
--- a/test/lib/load-all-commands.js
+++ b/test/lib/load-all-commands.js
@@ -1,27 +1,35 @@
-// Thanks to nyc not working properly with proxies this
-// doesn't affect coverage. but it does ensure that every command has a usage
-// that contains its name, and if it has completion it is a function
-const npm = require('../../lib/npm.js')
+// Thanks to nyc not working properly with proxies this doesn't affect
+// coverage. but it does ensure that every command has a usage that contains
+// its name, a description, and if it has completion it is a function
+const requireInject = require('require-inject')
+const npm = requireInject('../../lib/npm.js')
 const t = require('tap')
 const { cmdList } = require('../../lib/utils/cmd-list.js')
 
-t.test('load npm', t => npm.load(er => {
-  if (er)
-    throw er
-}))
-
+let npmOutput = []
+npm.output = (msg) => {
+  npmOutput = msg
+}
 t.test('load each command', t => {
-  t.plan(cmdList.length)
-  for (const cmd of cmdList.sort((a, b) => a.localeCompare(b))) {
-    t.test(cmd, t => {
-      const impl = npm.commands[cmd]
-      if (impl.completion) {
-        t.plan(3)
-        t.isa(impl.completion, 'function', 'completion, if present, is a function')
-      } else
-        t.plan(2)
-      t.isa(impl, 'function', 'implementation is a function')
-      t.match(impl.usage, cmd, 'usage contains the command')
-    })
-  }
+  t.plan(cmdList.length + 1)
+  npm.load((er) => {
+    t.notOk(er)
+    npm.config.set('usage', true)
+    for (const cmd of cmdList.sort((a, b) => a.localeCompare(b))) {
+      t.test(cmd, t => {
+        const impl = npm.commands[cmd]
+        if (impl.completion)
+          t.isa(impl.completion, 'function', 'completion, if present, is a function')
+        t.isa(impl, 'function', 'implementation is a function')
+        t.ok(impl.description, 'implementation has a description')
+        t.ok(impl.name, 'implementation has a name')
+        t.match(impl.usage, cmd, 'usage contains the command')
+        impl([], (err) => {
+          t.notOk(err)
+          t.match(npmOutput, impl.usage, 'usage is output')
+          t.end()
+        })
+      })
+    }
+  })
 })