feat(testlab): add skipIf helper

Signed-off-by: Miroslav Bajtoš <mbajtoss@gmail.com>

Author: bajtos

packages/testlab/README.md

@@ -47,6 +47,7 @@ Table of contents:
 - [sinon](#sinon) - Mocks, stubs and more.
 - [shot](#shot) - HTTP Request/Response stubs.
 - [validateApiSpec](#validateapispec) - Open API Spec validator.
+- [skipIf](#skipif) - Skip tests when a condition is met.
 - [skipOnTravis](#skipontravis) - Skip tests on Travis env.
 - [createRestAppClient](#createrestappclient) - Create a supertest client
   connected to a running RestApplication.
@@ -82,6 +83,35 @@ by Shot in your unit tests:
 - Code modifying core HTTP Response, including full request/response handlers
 - Code parsing Express HTTP Request or modifying Express HTTP Response
 
+### `skipIf`
+
+Helper function for skipping tests when a certain condition is met. Use this
+helper together with `it` or `describe`.
+
+```ts
+skipIf(someCondition, it, 'does something', async () => {
+  // the test code
+});
+```
+
+Unfortunately, type inference does not work well for `describe`, you have to
+help the compiler to figure out the correct types.
+
+```ts
+skipIf<[(this: Suite) => void], void>(
+  someCondition,
+  describe,
+  'some suite name',
+  () => {
+    // define the test cases
+  },
+);
+```
+
+Under the hood, `skipIf` invokes the provided test verb by default (e.g. `it`).
+When the provided condition was true, then it calls `.skip` instead (e.g.
+`it.skip`).
+
 ### `skipOnTravis`
 
 Helper function for skipping tests on Travis environment. If you need to skip

packages/testlab/src/index.ts

@@ -10,7 +10,7 @@ export * from './http-server-config';
 export * from './request';
 export * from './shot';
 export * from './sinon';
-export * from './skip-travis';
+export * from './skip';
 export * from './test-sandbox';
 export * from './to-json';
 export * from './validate-api-spec';

packages/testlab/src/skip-travis.ts renamed to packages/testlab/src/skip.ts

@@ -11,6 +11,41 @@ export type TestDefinition<ARGS extends unknown[], RETVAL> = (
   ...args: ARGS
 ) => RETVAL;
 
+/**
+ * Helper function for skipping tests when a certain condition is met.
+ *
+ * @example
+ * ```ts
+ * skipIf(
+ *   !connectorFeatures.freeFormProperties,
+ *   describe,
+ *  'free-form properties (strict: false)',
+ *   () => {
+ *     // the tests
+ *   }
+ * );
+ * ```
+ *
+ * @param skip - Should the test case/suite be skipped?
+ * @param verb - The function to invoke to define the test case or the test
+ * suite, e.g. `it` or `describe`.
+ * @param name - The test name (the first argument of `verb` function).
+ * @param args - Additional arguments (framework specific), typically a function
+ * implementing the test.
+ */
+export function skipIf<ARGS extends unknown[], RETVAL>(
+  skip: boolean,
+  verb: TestDefinition<ARGS, RETVAL> & {skip: TestDefinition<ARGS, RETVAL>},
+  name: string,
+  ...args: ARGS
+): RETVAL {
+  if (skip) {
+    return verb.skip(`[SKIPPED] ${name}`, ...args);
+  } else {
+    return verb(name, ...args);
+  }
+}
+
 /**
  * Helper function for skipping tests on Travis CI.
  *