Improved error messaging for enums

README.md

@@ -31,9 +31,9 @@ Supported browsers: Chrome, Firefox, Safari, Opera, Internet Explorer 9+.
 - JSON schema validation (powered by [ajv](https://github.com/epoberezkin/ajv)).
 
 ### Code editor
-- Format and compact JSON.
 - Colorized code (powered by [Ace](https://ace.c9.io)).
 - Inspect JSON (powered by [Ace](https://ace.c9.io)).
+- Format and compact JSON.
 - JSON schema validation (powered by [ajv](https://github.com/epoberezkin/ajv)).
 
 ### Text editor

examples/07_json_schema_validation.html

@@ -40,6 +40,9 @@ <h1>JSON schema validation</h1>
       "lastName": {
         "type": "string"
       },
+      "gender": {
+        "enum": ["male", "female"]
+      },
       "age": {
         "description": "Age in years",
         "type": "integer",
@@ -52,7 +55,8 @@ <h1>JSON schema validation</h1>
   var json = {
     firstName: 'John',
     lastName: 'Doe',
-    age: 28.5
+    gender: null,
+    age: 28
   };
 
   var options = {

src/js/treemode.js

@@ -370,12 +370,14 @@ treemode.validate = function () {
   if (this.validateSchema) {
     var valid = this.validateSchema(root.getValue());
     if (!valid) {
+      var schema = this.options.schema;
+
       // apply all new errors
       schemaErrors = this.validateSchema.errors
           .map(function findNode (error) {
             return {
               node: root.findNode(error.dataPath),
-              error: error
+              error: improveErrorMessages(error)
             }
           })
           .filter(function hasNode (entry) {
@@ -412,6 +414,29 @@ treemode.validate = function () {
       });
 };
 
+/**
+ * Improve the error messages of JSON schema errors
+ * @param {Object} error
+ * @return {Object} The error
+ */
+function improveErrorMessages (error) {
+  if (error.keyword === 'enum') {
+    var enums = util.getFromSchema(schema, error.schemaPath);
+    if (enums) {
+      enums = enums.map(function (value) {
+        return JSON.stringify(value);
+      });
+
+      if (enums.length > 5) {
+        enums = enums.slice(0, 5).concat(['(' + (enums.length - 5) + ' more...)']);
+      }
+      error.message = 'should be equal to one of: ' + enums.join(', ');
+    }
+  }
+
+  return error;
+}
+
 /**
  * Start autoscrolling when given mouse position is above the top of the
  * editor contents, or below the bottom.

src/js/util.js

@@ -660,6 +660,25 @@ exports.parsePath = function parsePath(jsonPath) {
   return [prop].concat(parsePath(remainder))
 };
 
+/**
+ * Retrieve a part of the schema
+ * @param {Object} schema
+ * @param {string} schemaPath   A path like "#/properties/gender/enum"
+ * @return {Object} Returns the found part of the schema, or undefined when not found.
+ */
+exports.getFromSchema = function (schema, schemaPath) {
+  var path = schemaPath.split('/');
+  path.shift(); // remove the first #
+
+  var obj = schema;
+  var prop;
+  while (prop = path.shift()) {
+    obj = obj[prop];
+  }
+
+  return obj;
+};
+
 /**
  * Test whether the child rect fits completely inside the parent rect.
  * @param {ClientRect} parent