feat: add validationErrors to schema mismatch errors

index.js

@@ -866,6 +866,7 @@ function buildValue (context, location, input) {
 
   if ((type === undefined || type === 'object') && (schema.anyOf || schema.oneOf)) {
     context.validatorSchemasIds.add(location.getSchemaId())
+    code = 'const errors = []\n'
 
     if (schema.type === 'object') {
       context.wrapObjects = false
@@ -885,8 +886,9 @@ function buildValue (context, location, input) {
       const schemaRef = optionLocation.getSchemaRef()
       const nestedResult = buildValue(context, optionLocation, input)
       code += `
-        ${index === 0 ? 'if' : 'else if'}(validator.validate("${schemaRef}", ${input}))
+        ${index === 0 ? 'if' : 'else if'}(validator.validate("${schemaRef}", ${input}, errors)) {
           ${nestedResult}
+        }
       `
     }
 
@@ -896,7 +898,9 @@ function buildValue (context, location, input) {
     }
 
     code += `
-      else throw new TypeError(\`The value of '${schemaRef}' does not match schema definition.\`)
+      else throw Object.assign(new TypeError(\`The value of '${schemaRef}' does not match schema definition.\`), {
+        validationErrors: errors
+      })
     `
     if (schema.type === 'object') {
       code += `

lib/validator.js

@@ -47,8 +47,10 @@ class Validator {
     }
   }
 
-  validate (schemaRef, data) {
-    return this.ajv.validate(schemaRef, data)
+  validate (schemaRef, data, errors) {
+    const valid = this.ajv.validate(schemaRef, data)
+    if (this.ajv.errors && Array.isArray(errors)) errors.push(...this.ajv.errors)
+    return valid
   }
 
   // Ajv does not support js date format. In order to properly validate objects containing a date,

test/any.test.js

@@ -154,7 +154,7 @@ test('empty schema on anyOf', (t) => {
 })
 
 test('should throw a TypeError with the path to the key of the invalid value /1', (t) => {
-  t.plan(1)
+  t.plan(3)
 
   // any on Foo codepath.
   const schema = {
@@ -186,11 +186,21 @@ test('should throw a TypeError with the path to the key of the invalid value /1'
 
   const stringify = build(schema)
 
-  t.throws(() => stringify({ kind: 'Baz', value: 1 }), new TypeError('The value of \'#\' does not match schema definition.'))
+  try {
+    stringify({ kind: 'Baz', value: 1 })
+    t.fail('should throw')
+  } catch (err) {
+    t.equal(err.message, 'The value of \'#\' does not match schema definition.')
+    t.same(err.validationErrors, [
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind', keyword: 'enum', params: { allowedValues: ['Foo'] } },
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind', keyword: 'enum', params: { allowedValues: ['Bar'] } }
+    ])
+    t.ok(err instanceof TypeError)
+  }
 })
 
 test('should throw a TypeError with the path to the key of the invalid value /2', (t) => {
-  t.plan(1)
+  t.plan(3)
 
   // any on Foo codepath.
   const schema = {
@@ -227,5 +237,15 @@ test('should throw a TypeError with the path to the key of the invalid value /2'
 
   const stringify = build(schema)
 
-  t.throws(() => stringify({ data: { kind: 'Baz', value: 1 } }), new TypeError('The value of \'#/properties/data\' does not match schema definition.'))
+  try {
+    stringify({ data: { kind: 'Baz', value: 1 } })
+    t.fail('should throw')
+  } catch (err) {
+    t.equal(err.message, 'The value of \'#/properties/data\' does not match schema definition.')
+    t.same(err.validationErrors, [
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind', keyword: 'enum', params: { allowedValues: ['Foo'] } },
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind', keyword: 'enum', params: { allowedValues: ['Bar'] } }
+    ])
+    t.ok(err instanceof TypeError)
+  }
 })