1 files changed, 34 insertions, 0 deletions
diff --git a/spec/frontend/__helpers__/matchers/to_validate_json_schema.js b/spec/frontend/__helpers__/matchers/to_validate_json_schema.js
new file mode 100644
index 00000000000..ff391f08c55
--- /dev/null
+++ b/spec/frontend/__helpers__/matchers/to_validate_json_schema.js
@@ -0,0 +1,34 @@
+// NOTE: Make sure to initialize ajv when using this helper
+
+const getAjvErrorMessage = ({ errors }) => {
+  return (errors || []).map((error) => {
+    return `Error with item ${error.instancePath}: ${error.message}`;
+  });
+};
+
+export function toValidateJsonSchema(testData, validator) {
+  if (!(validator instanceof Function && validator.schema)) {
+    return {
+      validator,
+      message: () =>
+        'Validator must be a validating function with property "schema", created with `ajv.compile`. See https://ajv.js.org/api.html#ajv-compile-schema-object-data-any-boolean-promise-any.',
+      pass: false,
+    };
+  }
+
+  const isValid = validator(testData);
+
+  return {
+    actual: testData,
+    message: () => {
+      if (isValid) {
+        // We can match, but still fail because we're in a `expect...not.` context
+        return 'Expected the given data not to pass the schema validation, but found that it was considered valid.';
+      }
+
+      const errorMessages = getAjvErrorMessage(validator).join('\n');
+      return `Expected the given data to pass the schema validation, but found that it was considered invalid. Errors:\n${errorMessages}`;
+    },
+    pass: isValid,
+  };
+}