help: show usage when help-search finds no results

Fix https://github.com/npm/cli/issues/1655

1 files changed, 85 insertions, 0 deletions

diff --git a/lib/utils/npm-usage.js b/lib/utils/npm-usage.js
new file mode 100644
index 000000000..845332915
--- /dev/null
+++ b/lib/utils/npm-usage.js
@@ -0,0 +1,85 @@
+const npm = require('../npm.js')
+const didYouMean = require('./did-you-mean.js')
+const { dirname } = require('path')
+const output = require('./output.js')
+const { cmdList } = require('./cmd-list')
+
+module.exports = (valid = true) => {
+  npm.config.set('loglevel', 'silent')
+  npm.log.level = 'silent'
+  output(`
+Usage: npm <command>
+
+npm install        install all the dependencies in your project
+npm install <foo>  add the <foo> dependency to your project
+npm test           run this project's tests
+npm run <foo>      run the script named <foo>
+npm <command> -h   quick help on <command>
+npm -l             display usage info for all commands
+npm help <term>    search for help on <term>
+npm help npm       more involved overview
+
+All commands:
+${npm.config.get('long') ? usages() : ('\n    ' + wrap(cmdList))}
+
+Specify configs in the ini-formatted file:
+    ${npm.config.get('userconfig')}
+or on the command line via: npm <command> --key=value
+
+More configuration info: npm help config
+Configuration fields: npm help 7 config
+
+npm@${npm.version} ${dirname(dirname(__dirname))}
+`)
+
+  if (npm.argv.length >= 1) {
+    output(didYouMean(npm.argv[0], cmdList))
+  }
+
+  if (!valid) {
+    process.exitCode = 1
+  }
+}
+
+const wrap = (arr) => {
+  var out = ['']
+  var l = 0
+  var line
+
+  line = process.stdout.columns
+  if (!line) {
+    line = 60
+  } else {
+    line = Math.min(60, Math.max(line - 16, 24))
+  }
+
+  arr.sort(function (a, b) { return a < b ? -1 : 1 })
+    .forEach(function (c) {
+      if (out[l].length + c.length + 2 < line) {
+        out[l] += ', ' + c
+      } else {
+        out[l++] += ','
+        out[l] = c
+      }
+    })
+  return out.join('\n    ').substr(2)
+}
+
+const usages = () => {
+  // return a string of <command>: <usage>
+  var maxLen = 0
+  return cmdList.reduce(function (set, c) {
+    set.push([c, require(`./${npm.deref(c)}.js`).usage || ''])
+    maxLen = Math.max(maxLen, c.length)
+    return set
+  }, []).sort((a, b) => {
+    return a[0].localeCompare(b[0])
+  }).map(function (item) {
+    var c = item[0]
+    var usage = item[1]
+    return '\n    ' +
+      c + (new Array(maxLen - c.length + 2).join(' ')) +
+      (usage.split('\n').join('\n' + (new Array(maxLen + 6).join(' '))))
+  }).join('\n')
+}
+