fix: update schema for index and methods properties (#1397)

Author: snitin315

src/options.json

@@ -24,7 +24,7 @@
       "type": "array",
       "items": {
         "type": "string",
-        "minlength": "1"
+        "minLength": 1
       }
     },
     "headers": {
@@ -116,7 +116,7 @@
         },
         {
           "type": "string",
-          "minlength": "1"
+          "minLength": 1
         }
       ]
     }

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

@@ -42,37 +42,37 @@ exports[`validation should throw an error on the "headers" option with "true" va
 exports[`validation should throw an error on the "index" option with "{}" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.index should be one of these:
-   boolean | string
+   boolean | non-empty string
    -> Allows to serve an index of the directory.
    -> Read more at https://github.com/webpack/webpack-dev-middleware#index
    Details:
     * options.index should be a boolean.
-    * options.index should be a string."
+    * options.index should be a non-empty string."
 `;
 
 exports[`validation should throw an error on the "index" option with "0" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.index should be one of these:
-   boolean | string
+   boolean | non-empty string
    -> Allows to serve an index of the directory.
    -> Read more at https://github.com/webpack/webpack-dev-middleware#index
    Details:
     * options.index should be a boolean.
-    * options.index should be a string."
+    * options.index should be a non-empty string."
 `;
 
 exports[`validation should throw an error on the "methods" option with "{}" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.methods should be an array:
-   [string, ...]
+   [non-empty string, ...]
    -> Allows to pass the list of HTTP request methods accepted by the middleware.
    -> Read more at https://github.com/webpack/webpack-dev-middleware#methods"
 `;
 
 exports[`validation should throw an error on the "methods" option with "true" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.methods should be an array:
-   [string, ...]
+   [non-empty string, ...]
    -> Allows to pass the list of HTTP request methods accepted by the middleware.
    -> Read more at https://github.com/webpack/webpack-dev-middleware#methods"
 `;