feat: validate maxFileSize (#3)

* feat: validate `maxFileSize`
* feat: parse file size string like "512KB"
* feat: custom error messages

index.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const Ajv = require('ajv');
+const bytes = require('bytes');
 const jsonSchema = require('./manifest-schema.json');
 const validateUrl = require('./src/validate-https-url');
 
@@ -11,10 +12,14 @@ const validateUrl = require('./src/validate-https-url');
  */
 module.exports = function(json, options) {
   options = options || {};
-  let relativePath = str => true;
-  if (options.relativePath) {
+  let relativePath = () => true;
+  let maxFileSize = () => true;
+  if (typeof options.relativePath === 'function') {
     relativePath = options.relativePath;
   }
+  if (typeof options.maxFileSize === 'function') {
+    maxFileSize = options.maxFileSize;
+  }
   const ajv = new Ajv({
     allErrors: true,
     unknownFormats: true,
@@ -25,6 +30,26 @@ module.exports = function(json, options) {
       'relative-path': relativePath,
     },
   });
+
+  ajv.addKeyword('maxFileSize', {
+    validate: function validateMaxFileSize(schema, data) {
+      // schema: max file size like "512KB" or 123 (in bytes)
+      // data: path to the file
+      const maxBytes = bytes.parse(schema);
+      const valid = maxFileSize(maxBytes, data);
+      if (!valid) {
+        validateMaxFileSize.errors = [{
+          keyword: 'maxFileSize',
+          message: `file size should be <= ${schema}`,
+          params: {
+            limit: maxBytes,
+          },
+        }];
+      }
+      return valid;
+    },
+  });
+
   const validate = ajv.compile(jsonSchema);
   const valid = validate(json);
   return {valid: valid, errors: transformErrors(validate.errors)};

manifest-schema.json

@@ -65,7 +65,8 @@
       "type": "string",
       "description": "internal only",
       "minLength": 1,
-      "format": "relative-path"
+      "format": "relative-path",
+      "maxFileSize": "512KB"
     },
     "homepage_url": {
       "type": "object",
@@ -113,6 +114,7 @@
           "description": "internal only",
           "type": "string",
           "format": "relative-path",
+          "maxFileSize": "65535B",
           "minLength": 1
         },
         "js": {
@@ -149,7 +151,8 @@
         "anyOf": [{
           "format": "https-url"
         }, {
-          "format": "relative-path"
+          "format": "relative-path",
+          "maxFileSize": "512KB"
         }],
         "maxItems": 30
       }

package.json

@@ -15,6 +15,7 @@
   },
   "dependencies": {
     "ajv": "^4.11.5",
+    "bytes": "^2.5.0",
     "isomorphic-url": "1.0.0-alpha12"
   },
   "devDependencies": {

test/index.js

@@ -125,6 +125,43 @@ describe('validator', () => {
     assert(actual.errors[1].keyword === 'format');
     assert(actual.errors[2].keyword === 'anyOf');
   });
+
+  describe('maxFileSize', () => {
+    it('valid file size', () => {
+      let called = 0;
+      const actual = validator(json({
+      }), {
+        maxFileSize(maxFileSizeInBytes, path) {
+          assert(maxFileSizeInBytes === 524288);
+          assert(path === 'image/icon.png');
+          called++;
+          return true;
+        },
+      });
+      assert(called === 1);
+      assert(actual.valid === true);
+    });
+
+    it('invalid file size', () => {
+      const actual = validator(json({
+      }), {
+        maxFileSize(maxFileSizeInBytes, path) {
+          return false;
+        },
+      });
+      assert(actual.valid === false);
+      assert(actual.errors.length === 1);
+      assert.deepEqual(actual.errors[0], {
+        dataPath: '.icon',
+        keyword: 'maxFileSize',
+        message: 'file size should be <= 512KB',
+        params: {
+          limit: 524288,
+        },
+        schemaPath: '#/properties/icon/maxFileSize',
+      });
+    });
+  });
 });
 
 /**

yarn.lock

@@ -122,6 +122,10 @@ builtin-modules@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/builtin-modules/-/builtin-modules-1.1.1.tgz#270f076c5a72c02f5b65a47df94c5fe3a278892f"
 
+bytes@^2.5.0:
+  version "2.5.0"
+  resolved "https://registry.yarnpkg.com/bytes/-/bytes-2.5.0.tgz#4c9423ea2d252c270c41b2bdefeff9bb6b62c06a"
+
 call-matcher@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/call-matcher/-/call-matcher-1.0.1.tgz#5134d077984f712a54dad3cbf62de28dce416ca8"