docs: auto-generate synopsis sections

Fixes npm#4189

docs/content/commands/npm-init.md

@@ -6,13 +6,17 @@ description: Create a package.json file
 
 ### Synopsis
 
+<!-- AUTOGENERATED USAGE DESCRIPTIONS START -->
+
 ```bash
 npm init [--yes|-y|--scope]
 npm init <@scope> (same as `npm exec <@scope>/create`)
 npm init [<@scope>/]<name> (same as `npm exec [<@scope>/]create-<name>`)
 npm init [-w <dir>] [args...]
 ```
 
+<!-- AUTOGENERATED USAGE DESCRIPTIONS END -->
+
 ### Description
 
 `npm init <initializer>` can be used to set up a new or existing npm

scripts/config-doc-command.js

@@ -6,16 +6,18 @@ const configDoc = process.argv[2]
 const commandFile = process.argv[3]
 
 // Note: commands without params skip this whole process.
-const { params } = require(resolve(commandFile))
+const { params, usage } = require(resolve(commandFile))
 
-const describeAll = () =>
-  params.map(name => definitions[name].describe()).join(
+const describeAll = (content) =>
+  content.map(name => definitions[name].describe()).join(
     '\n\n<!-- automatically generated, do not edit manually -->\n' +
       '<!-- see lib/utils/config/definitions.js -->\n\n'
   )
 
 const addBetweenTags = (doc, startTag, endTag, body) => {
   const startSplit = doc.split(startTag)
+  console.log(startSplit)
+
   if (startSplit.length !== 2) {
     throw new Error('Did not find exactly one start tag')
   }
@@ -42,14 +44,28 @@ const addBetweenTags = (doc, startTag, endTag, body) => {
 const addDescriptions = doc => {
   const startTag = '<!-- AUTOGENERATED CONFIG DESCRIPTIONS START -->'
   const endTag = '<!-- AUTOGENERATED CONFIG DESCRIPTIONS END -->'
-  return addBetweenTags(doc, startTag, endTag, describeAll())
+  return addBetweenTags(doc, startTag, endTag, describeAll(params))
+}
+
+const addUsageDescriptions = doc => {
+  const startTag = '<!-- AUTOGENERATED USAGE DESCRIPTIONS START -->'
+  const endTag = '<!-- AUTOGENERATED USAGE DESCRIPTIONS END -->'
+  return addBetweenTags(doc, startTag, endTag, describeAll(usage))
 }
 
 // always write SOMETHING so that Make sees the file is up to date.
 const doc = readFileSync(configDoc, 'utf8')
 const hasTag = doc.includes('<!-- AUTOGENERATED CONFIG DESCRIPTIONS START -->')
-const newDoc = params && hasTag ? addDescriptions(doc) : doc
+const hasUsageTag = doc.includes('<!-- AUTOGENERATED SYNOPSIS DESCRIPTIONS START -->')
+
+let newDoc = params && hasTag ? addDescriptions(doc) : doc
+newDoc = usage && hasUsageTag ? addUsageDescriptions(newDoc) : newDoc
+
 if (params && !hasTag) {
   console.error('WARNING: did not find config description section', configDoc)
 }
+
+if (usage && !hasUsageTag) {
+  console.error('WARNING: did not find usage description section', configDoc)
+}
 writeFileSync(configDoc, newDoc)