test: add full validation error output for failed test

Allows developers to directly copy the error to the fixture file.

Author: yT0n1

packages/element-templates-json-schema-shared/test/helpers/index.js

@@ -3,6 +3,8 @@ const {
   set
 } = require('min-dash');
 
+const chai = require('chai');
+
 const { default: Ajv } = require('ajv');
 const AjvErrors = require('ajv-errors');
 
@@ -53,4 +55,20 @@ function setErrorMessage(schema, error) {
   ];
 
   return set(schema, errorMessagePath, errorMessage);
-}
+}
+
+function eqlErrors(chai, utils) {
+
+  const Assertion = chai.Assertion;
+
+  Assertion.addMethod('eqlErrors', function(expectedErrors, filter) {
+
+    const actualErrors = this._obj;
+
+    // formats the validation errors, so that they can be used directly in the fixture files.
+    this.eql(expectedErrors,
+      `Errors from validation do not match expected.\n\tValidation returned this error (you can use it in the fixture):\n\t${JSON.stringify(actualErrors, null, 2).replace(/"([^"]+)":/g, '$1:')}\n`);
+  });
+}
+
+chai.use(eqlErrors);

packages/zeebe-element-templates-json-schema/test/spec/validationSpec.js

@@ -49,7 +49,7 @@ function createTest(name, file, it) {
     } = validateTemplate(template);
 
     // then
-    expect(errors).to.eql(expectedErrors);
+    expect(errors).to.eqlErrors(expectedErrors);
   });
 }