feat: add validationErrors to schema mismatch errors

Author: MoLow

index.js

@@ -122,20 +122,24 @@ function build (schema, options) {
 
   let contextFunctionCode
 
+  const resetValidatorErrors = (context.validatorSchemasIds.size > 0) ? 'validator.resetErrors();' : ''
+
   // If we have only the invocation of the 'anonymous0' function, we would
   // basically just wrap the 'anonymous0' function in the 'main' function and
   // and the overhead of the intermediate variable 'json'. We can avoid the
   // wrapping and the unnecessary memory allocation by aliasing 'anonymous0' to
   // 'main'
   if (code === 'json += anonymous0(input)') {
     contextFunctionCode = `
+    ${resetValidatorErrors}
     ${context.functions.join('\n')}
     const main = anonymous0
     return main
     `
   } else {
     contextFunctionCode = `
     function main (input) {
+      ${resetValidatorErrors}
       let json = ''
       ${code}
       return json
@@ -896,7 +900,7 @@ function buildValue (context, location, input) {
     }
 
     code += `
-      else throw new TypeError(\`The value of '${schemaRef}' does not match schema definition.\`)
+      else validator.throwAccumulatedErrors("${schemaRef}");
     `
     if (schema.type === 'object') {
       code += `

lib/validator.js

@@ -26,6 +26,7 @@ class Validator {
       }
     })
 
+    this._errors = []
     this._ajvSchemas = {}
     this._ajvOptions = ajvOptions || {}
   }
@@ -47,8 +48,20 @@ class Validator {
     }
   }
 
+  resetErrors () {
+    this._errors = []
+  }
+
   validate (schemaRef, data) {
-    return this.ajv.validate(schemaRef, data)
+    const result = this.ajv.validate(schemaRef, data)
+    if (this.ajv.errors) this._errors.push(...this.ajv.errors)
+    return result
+  }
+
+  throwAccumulatedErrors (schemaRef) {
+    const error = new TypeError(`The value of '${schemaRef}' does not match schema definition.`)
+    error.validationErrors = this._errors
+    throw error
   }
 
   // Ajv does not support js date format. In order to properly validate objects containing a date,

test/any.test.js

@@ -186,7 +186,12 @@ 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.'))
+  t.throws(() => stringify({ kind: 'Baz', value: 1 }), Object.assign(new TypeError('The value of \'#\' does not match schema definition.'), {
+    validationErrors: [
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind' },
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind' }
+    ]
+  }))
 })
 
 test('should throw a TypeError with the path to the key of the invalid value /2', (t) => {
@@ -227,5 +232,10 @@ 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.'))
+  t.throws(() => stringify({ data: { kind: 'Baz', value: 1 } }), Object.assign(new TypeError('The value of \'#/properties/data\' does not match schema definition.'), {
+    validationErrors: [
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind' },
+      { message: 'must be equal to one of the allowed values', schemaPath: '#/properties/kind/enum', instancePath: '/kind' }
+    ]
+  }))
 })