2 files changed, 24 insertions, 3 deletions
diff --git a/src/ts/utils/assert.ts b/src/ts/utils/assert.ts
index a29ae922d..972047118 100644
--- a/src/ts/utils/assert.ts
+++ b/src/ts/utils/assert.ts
@@ -1,6 +1,7 @@
 import * as _ from 'lodash';
 import * as BigNumber from 'bignumber.js';
 import Web3 = require('web3');
+import {SchemaValidator} from './schema_validator';
 
 export const assert = {
     isBigNumber(variableName: string, value: BigNumber.BigNumber) {
@@ -14,12 +15,18 @@ export const assert = {
         const web3 = new Web3();
         this.assert(web3.isAddress(value), this.typeAssertionMessage(variableName, 'ETHAddressHex', value));
     },
-    isObject(variableName: string, value: object) {
-        this.assert(_.isObject(value), this.typeAssertionMessage(variableName, 'object', value));
-    },
     isNumber(variableName: string, value: number) {
         this.assert(_.isFinite(value), this.typeAssertionMessage(variableName, 'number', value));
     },
+    doesConformToSchema(variableName: string, value: object, schema: Schema) {
+        const schemaValidator = new SchemaValidator();
+        const validationResult = schemaValidator.validate(value, schema);
+        const hasValidationErrors = validationResult.errors.length > 0;
+        const msg = `Expected ${variableName} to conform to schema ${schema.id}
+Encountered: ${JSON.stringify(value, null, '\t')}
+Validation errors: ${validationResult.errors.join(', ')}`;
+        this.assert(!hasValidationErrors, msg);
+    },
     assert(condition: boolean, message: string) {
         if (!condition) {
             throw new Error(message);
diff --git a/src/ts/utils/schema_validator.ts b/src/ts/utils/schema_validator.ts
new file mode 100644
index 000000000..bd2f97d2b
--- /dev/null
+++ b/src/ts/utils/schema_validator.ts
@@ -0,0 +1,14 @@
+import {Validator, ValidatorResult} from 'jsonschema';
+import {ECSignatureSchema, ECSignatureParameter} from '../schemas/ec_signature_schema';
+
+export class SchemaValidator {
+    private validator: Validator;
+    constructor() {
+        this.validator = new Validator();
+        this.validator.addSchema(ECSignatureParameter, ECSignatureParameter.id);
+        this.validator.addSchema(ECSignatureSchema, ECSignatureSchema.id);
+    }
+    public validate(instance: object, schema: Schema): ValidatorResult {
+        return this.validator.validate(instance, schema);
+    }
+}