fix: output description for static options (#3246)

lib/options.json

@@ -7,7 +7,8 @@
       "properties": {
         "directory": {
           "type": "string",
-          "minLength": 1
+          "minLength": 1,
+          "description": "Directory for static contents."
         },
         "staticOptions": {
           "type": "object",
@@ -48,9 +49,11 @@
               "type": "boolean"
             },
             {
-              "type": "object"
+              "type": "object",
+              "description": "options for watch, you can find at https://github.com/paulmillr/chokidar"
             }
-          ]
+          ],
+          "description": "Watch for files in static content directory."
         }
       }
     },

test/__snapshots__/validate-options.test.js.snap.webpack4

@@ -308,6 +308,12 @@ exports[`options validate should throw an error on the "static" option with '' v
  - configuration.static should be an non-empty string."
 `;
 
+exports[`options validate should throw an error on the "static" option with '{"directory":false}' value 1`] = `
+"ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
+ - configuration.static.directory should be a non-empty string.
+   -> Directory for static contents."
+`;
+
 exports[`options validate should throw an error on the "static" option with '{"publicPath":false}' value 1`] = `
 "ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
  - configuration.static should be one of these:
@@ -338,6 +344,22 @@ exports[`options validate should throw an error on the "static" option with '{"s
          object { … }"
 `;
 
+exports[`options validate should throw an error on the "static" option with '{"watch":10}' value 1`] = `
+"ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
+ - configuration.static should be one of these:
+   boolean | non-empty string | object { directory?, staticOptions?, publicPath?, serveIndex?, watch? } | [non-empty string | object { directory?, staticOptions?, publicPath?, serveIndex?, watch? }, ...] (should not have fewer than 1 item)
+   -> It is possible to configure advanced options for serving static files from directory. See the Express documentation for the possible options. https://webpack.js.org/configuration/dev-server/#devserverstatic
+   Details:
+    * configuration.static.watch should be one of these:
+      boolean | object { … }
+      -> Watch for files in static content directory.
+      Details:
+       * configuration.static.watch should be a boolean.
+       * configuration.static.watch should be an object:
+         object { … }
+         -> options for watch, you can find at https://github.com/paulmillr/chokidar"
+`;
+
 exports[`options validate should throw an error on the "static" option with '0' value 1`] = `
 "ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
  - configuration.static should be one of these:

test/__snapshots__/validate-options.test.js.snap.webpack5

@@ -308,6 +308,12 @@ exports[`options validate should throw an error on the "static" option with '' v
  - configuration.static should be an non-empty string."
 `;
 
+exports[`options validate should throw an error on the "static" option with '{"directory":false}' value 1`] = `
+"ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
+ - configuration.static.directory should be a non-empty string.
+   -> Directory for static contents."
+`;
+
 exports[`options validate should throw an error on the "static" option with '{"publicPath":false}' value 1`] = `
 "ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
  - configuration.static should be one of these:
@@ -338,6 +344,22 @@ exports[`options validate should throw an error on the "static" option with '{"s
          object { … }"
 `;
 
+exports[`options validate should throw an error on the "static" option with '{"watch":10}' value 1`] = `
+"ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
+ - configuration.static should be one of these:
+   boolean | non-empty string | object { directory?, staticOptions?, publicPath?, serveIndex?, watch? } | [non-empty string | object { directory?, staticOptions?, publicPath?, serveIndex?, watch? }, ...] (should not have fewer than 1 item)
+   -> It is possible to configure advanced options for serving static files from directory. See the Express documentation for the possible options. https://webpack.js.org/configuration/dev-server/#devserverstatic
+   Details:
+    * configuration.static.watch should be one of these:
+      boolean | object { … }
+      -> Watch for files in static content directory.
+      Details:
+       * configuration.static.watch should be a boolean.
+       * configuration.static.watch should be an object:
+         object { … }
+         -> options for watch, you can find at https://github.com/paulmillr/chokidar"
+`;
+
 exports[`options validate should throw an error on the "static" option with '0' value 1`] = `
 "ValidationError: Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
  - configuration.static should be one of these:

test/validate-options.test.js

@@ -277,6 +277,12 @@ const tests = {
       {
         serveIndex: 'true',
       },
+      {
+        directory: false,
+      },
+      {
+        watch: 10,
+      },
     ],
   },
   transportMode: {